Tropical
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![]() Tropical Cyclone BENILDE Southern Hemisphere Summary |
WTXS22 PGTW 20111228 02:00z MSGID/GENADMIN/NAVMARFCSTCEN PEARL HARBOR HI/JTWC// SUBJ/TROPICAL CYCLONE FORMATION ALERT// RMKS/ 1. FORMATION OF A SIGNIFICANT TROPICAL CYCLONE IS POSSIBLE WITHIN 090 NM EITHER SIDE OF A LINE FROM 11.8S 91.6E TO 13.2S 85.9E WITHIN THE NEXT 12 TO 24 HOURS. AVAILABLE DATA DOES NOT JUSTIFY ISSUANCE OF NUMBERED TROPICAL CYCLONE WARNINGS AT THIS TIME. WINDS IN THE AREA ARE ESTIMATED TO BE 28 TO 32 KNOTS. METSAT IMAGERY AT 280000Z INDICATES THAT A CIRCULATION CENTER IS LOCATED NEAR 11.9S 91.2E. THE SYSTEM IS MOVING WESTWARD AT 16 KNOTS. 2. REMARKS: THE AREA OF CONVECTION PREVIOUSLY LOCATED NEAR 11.0S 94.0E, IS NOW LOCATED NEAR 11.9S 91.2E, APPROXIMATELY 340 NM WEST OF THE COCOS ISLANDS. RECENT ANIMATED INFRARED SATELLITE IMAGERY INDICATES A BROAD CIRCULATION WITH CONVECTION CONTINUING TO DEEPEN AND CONSOLIDATE AROUND THE LOW LEVEL CIRCULATION CENTER (LLCC). A 272340Z TRMM MICROWAVE IMAGE CONFIRMS THE CONSOLIDATION, DEPICTING FRAGMENTED, BUT CURVED BANDING WRAPPING INTO THE LLCC. UPPER LEVEL ANALYSIS INDICATES THE SYSTEM LIES JUST EQUATORWARD OF THE SUBTROPICAL RIDGE AXIS IN A DIFFLUENT REGION WITH APPROXIMATELY 10 TO 15 KNOTS OF VERTICAL WIND SHEAR. VERTICAL WIND SHEAR IS EXPECTED TO EASE AS THE SYSTEM CONTINUES TO MOVE SLIGHTLY SOUTH OF WEST AND CLOSER TO THE RIDGE AXIS. SEA SURFACE TEMPERATURES IN THE AREA ARE ADEQUATE AT APPROXIMATELY 28 DEGREES CELSIUS. MAXIMUM SUSTAINED SURFACE WINDS ARE ESTIMATED AT 28 TO 32 KNOTS. MINIMUM SEA LEVEL PRESSURE IS ESTIMATED TO BE NEAR 1000 MB. THE POTENTIAL FOR THE DEVELOPMENT OF A SIGNIFICANT TROPICAL CYCLONE WITHIN THE NEXT 24 HOURS IS HIGH. 3. THIS ALERT WILL BE REISSUED, UPGRADED TO WARNING OR CANCELLED BY 290200Z. 4. SEE REF A FOR DETAILS ON A TROPICAL CYCLONE FORMATION ALERT LOCATED NEAR 14.5S 135.8E ========================================================================= WTXS32 PGTW 20111228 09:00z MSGID/GENADMIN/NAVMARFCSTCEN PEARL HARBOR HI/JTWC// SUBJ/TROPICAL CYCLONE 04S (FOUR) WARNING NR 001// REF/A/MSG/NAVMARFCSTCEN PEARL HARBOR HI/280152ZDEC2011// AMPN/REF A IS A TROPICAL CYCLONE FORMATION ALERT.// RMKS/ 1. TROPICAL CYCLONE 04S (FOUR) WARNING NR 001 01 ACTIVE TROPICAL CYCLONE IN SOUTHIO MAX SUSTAINED WINDS BASED ON ONE-MINUTE AVERAGE WIND RADII VALID OVER OPEN WATER ONLY --- WARNING POSITION: 280600Z --- NEAR 12.1S 89.6E MOVEMENT PAST SIX HOURS - 265 DEGREES AT 16 KTS POSITION ACCURATE TO WITHIN 060 NM POSITION BASED ON CENTER LOCATED BY SATELLITE PRESENT WIND DISTRIBUTION: MAX SUSTAINED WINDS - 035 KT, GUSTS 045 KT WIND RADII VALID OVER OPEN WATER ONLY REPEAT POSIT: 12.1S 89.6E --- FORECASTS: 12 HRS, VALID AT: 281800Z --- 12.1S 87.4E MAX SUSTAINED WINDS - 035 KT, GUSTS 045 KT WIND RADII VALID OVER OPEN WATER ONLY VECTOR TO 24 HR POSIT: 265 DEG/ 11 KTS --- 24 HRS, VALID AT: 290600Z --- 12.3S 85.1E MAX SUSTAINED WINDS - 035 KT, GUSTS 045 KT WIND RADII VALID OVER OPEN WATER ONLY VECTOR TO 36 HR POSIT: 265 DEG/ 11 KTS --- 36 HRS, VALID AT: 291800Z --- 12.5S 82.8E MAX SUSTAINED WINDS - 040 KT, GUSTS 050 KT WIND RADII VALID OVER OPEN WATER ONLY RADIUS OF 034 KT WINDS - 060 NM NORTHEAST QUADRANT 050 NM SOUTHEAST QUADRANT 050 NM SOUTHWEST QUADRANT 060 NM NORTHWEST QUADRANT VECTOR TO 48 HR POSIT: 260 DEG/ 11 KTS --- EXTENDED OUTLOOK: 48 HRS, VALID AT: 300600Z --- 12.9S 80.5E MAX SUSTAINED WINDS - 050 KT, GUSTS 065 KT WIND RADII VALID OVER OPEN WATER ONLY RADIUS OF 034 KT WINDS - 070 NM NORTHEAST QUADRANT 060 NM SOUTHEAST QUADRANT 060 NM SOUTHWEST QUADRANT 070 NM NORTHWEST QUADRANT VECTOR TO 72 HR POSIT: 255 DEG/ 08 KTS --- 72 HRS, VALID AT: 310600Z --- 13.8S 77.5E MAX SUSTAINED WINDS - 060 KT, GUSTS 075 KT WIND RADII VALID OVER OPEN WATER ONLY RADIUS OF 050 KT WINDS - 035 NM NORTHEAST QUADRANT 035 NM SOUTHEAST QUADRANT 035 NM SOUTHWEST QUADRANT 035 NM NORTHWEST QUADRANT RADIUS OF 034 KT WINDS - 080 NM NORTHEAST QUADRANT 070 NM SOUTHEAST QUADRANT 070 NM SOUTHWEST QUADRANT 080 NM NORTHWEST QUADRANT VECTOR TO 96 HR POSIT: 240 DEG/ 07 KTS --- LONG RANGE OUTLOOK: --- 96 HRS, VALID AT: 010600Z --- 15.3S 74.9E MAX SUSTAINED WINDS - 070 KT, GUSTS 085 KT WIND RADII VALID OVER OPEN WATER ONLY VECTOR TO 120 HR POSIT: 220 DEG/ 06 KTS --- 120 HRS, VALID AT: 020600Z --- 17.2S 73.3E MAX SUSTAINED WINDS - 065 KT, GUSTS 080 KT WIND RADII VALID OVER OPEN WATER ONLY --- REMARKS: 280900Z POSITION NEAR 12.1S 89.1E. TROPICAL CYCLONE (TC) 04S, LOCATED APPROXIMATELY 1050 NM EAST- SOUTHEAST OF DIEGO GARCIA, HAS TRACKED WESTWARD AT 16 KNOTS OVER THE PAST SIX HOURS. TC 04S HAS CONSOLIDATED OVER THE PAST 12 HOURS WITH A LARGE CLUSTER OF DEEP CONVECTION PERSISTING OVER THE WESTERN SEMI- CIRCLE OF A PARTIALLY-EXPOSED, WELL-DEFINED LOW-LEVEL CIRCULATION CENTER (LLCC). THIS CONSOLIDATION IS EVIDENT IN THE TOTAL PRECIPITABLE WATER LOOP WHICH SHOWS AN ENVELOPE OF DEEP MOISTURE ASSOCIATED WITH THE SYSTEM. THE UPPER-LEVEL ENVIRONMENT IS CURRENTLY MARGINAL WITH AN ANTICYCLONE DISPLACED TO THE SOUTHEAST PRODUCING EASTERLY, DIFFLUENT FLOW AND MODERATE (20-25 KNOTS) VERTICAL WIND SHEAR (VWS). BASED ON MULTISPECTRAL SATELLITE IMAGERY AND A 280313Z METOP-A IMAGE, THE LLCC HAS STRENGTHENED AND THE CURRENT INTENSITY IS ASSESSED AT 35 KNOTS; HOWEVER, DATA HAS BEEN SPARSE AND A 280315Z ASCAT IMAGE SHOWED ONLY 20-25 KNOT WINDS OVER THE WESTERN SEMI- CIRCLE. DVORAK ESTIMATES HAVE INCREASED TO 35 KNOTS FROM BOTH KNES AND PGTW AND PROVIDED JUSTIFICATION FOR THE 35-KNOT ASSESSMENT AND INITIAL WARNING. THERE IS FAIR CONFIDENCE IN THE CURRENT POSITION BASED ON THE METOP-A IMAGE AND MSI. TC 04S IS FORECAST TO TRACK WESTWARD UNDER THE LOW-LEVEL SUBTROPICAL RIDGE (STR) TO THE SOUTH BUT SHOULD TRACK MORE WEST-SOUTHWESTWARD AFTER TAU 36 AS IT STRENGTHENS AND TRACKS TOWARD A DEVELOPING WEAKNESS IN THE STR CREATED BY AN APPROACHING SHORT-WAVE TROUGH. MODEL GUIDANCE IS IN TIGHT AGREEMENT EXCEPT FOR WBAR WHICH INDICATES VERY SLOW TRACK SPEEDS, THEREFORE, THIS FORECAST IS POSITIONED FASTER THAN THE MODEL CONSENSUS. THE GREATEST UNCERTAINTY IN THIS FORECAST DEALS WITH THE INTENSITY FORECAST. BOTH GFDN AND STIPS GUIDANCE INDICATES A PEAK INTENSITY OF 90 KNOTS, HOWEVER, THE MAJORITY OF MODEL GUIDANCE SHOWS AN ANTICYCLONE OVER THE SYSTEM, WHICH AS MENTIONED, IS NOT OCCURRING. THEREFORE, THE INTENSITY TREND IS EXPECTED TO BE FLAT THROUGH TAU 36 UNTIL THE VWS DECREASES. TC 04S IS EXPECTED TO INTENSIFY AT A GREATER RATE AFTER TAU 36 DUE TO IMPROVED POLEWARD OUTFLOW ASSOCIATED WITH THE APPROACHING UPPER-LEVEL TROUGH WITH A PEAK INTENSITY OF 70 KNOTS BY TAU 96. AFTER TAU 96, THE SYSTEM IS FORECAST TO WEAKEN AS IT ENCOUNTERS AN UPPER-LEVEL TROUGH AND INCREASING VWS AND CONVERGENCE ALOFT. THIS WARNING SUPERSEDES AND CANCELS REF A, NAVMARFCSTCEN 280152Z DEC 12 TROPICAL CYCLONE FORMATION ALERT (WTXS22 PGTW 280200). MAXIMUM SIGNIFICANT WAVE HEIGHT AT 280600Z IS 10 FEET. NEXT WARNINGS AT 282100Z AND 290900Z.// ========================================================================= WTXS32 PGTW 20111228 21:00z MSGID/GENADMIN/NAVMARFCSTCEN PEARL HARBOR HI/JTWC// SUBJ/TROPICAL CYCLONE 04S (FOUR) WARNING NR 002// RMKS/ 1. TROPICAL CYCLONE 04S (FOUR) WARNING NR 002 01 ACTIVE TROPICAL CYCLONE IN SOUTHIO MAX SUSTAINED WINDS BASED ON ONE-MINUTE AVERAGE WIND RADII VALID OVER OPEN WATER ONLY --- WARNING POSITION: 281800Z --- NEAR 12.5S 87.2E MOVEMENT PAST SIX HOURS - 255 DEGREES AT 13 KTS POSITION ACCURATE TO WITHIN 060 NM POSITION BASED ON CENTER LOCATED BY SATELLITE PRESENT WIND DISTRIBUTION: MAX SUSTAINED WINDS - 035 KT, GUSTS 045 KT WIND RADII VALID OVER OPEN WATER ONLY REPEAT POSIT: 12.5S 87.2E --- FORECASTS: 12 HRS, VALID AT: 290600Z --- 12.7S 84.8E MAX SUSTAINED WINDS - 035 KT, GUSTS 045 KT WIND RADII VALID OVER OPEN WATER ONLY VECTOR TO 24 HR POSIT: 265 DEG/ 11 KTS --- 24 HRS, VALID AT: 291800Z --- 12.8S 82.5E MAX SUSTAINED WINDS - 040 KT, GUSTS 050 KT WIND RADII VALID OVER OPEN WATER ONLY RADIUS OF 034 KT WINDS - 050 NM NORTHEAST QUADRANT 060 NM SOUTHEAST QUADRANT 060 NM SOUTHWEST QUADRANT 050 NM NORTHWEST QUADRANT VECTOR TO 36 HR POSIT: 265 DEG/ 10 KTS --- 36 HRS, VALID AT: 300600Z --- 13.0S 80.5E MAX SUSTAINED WINDS - 050 KT, GUSTS 065 KT WIND RADII VALID OVER OPEN WATER ONLY RADIUS OF 034 KT WINDS - 060 NM NORTHEAST QUADRANT 070 NM SOUTHEAST QUADRANT 070 NM SOUTHWEST QUADRANT 060 NM NORTHWEST QUADRANT VECTOR TO 48 HR POSIT: 250 DEG/ 09 KTS --- EXTENDED OUTLOOK: 48 HRS, VALID AT: 301800Z --- 13.6S 78.8E MAX SUSTAINED WINDS - 065 KT, GUSTS 080 KT WIND RADII VALID OVER OPEN WATER ONLY RADIUS OF 050 KT WINDS - 030 NM NORTHEAST QUADRANT 035 NM SOUTHEAST QUADRANT 035 NM SOUTHWEST QUADRANT 030 NM NORTHWEST QUADRANT RADIUS OF 034 KT WINDS - 075 NM NORTHEAST QUADRANT 085 NM SOUTHEAST QUADRANT 085 NM SOUTHWEST QUADRANT 075 NM NORTHWEST QUADRANT VECTOR TO 72 HR POSIT: 225 DEG/ 06 KTS --- 72 HRS, VALID AT: 311800Z --- 15.2S 77.1E MAX SUSTAINED WINDS - 090 KT, GUSTS 110 KT WIND RADII VALID OVER OPEN WATER ONLY RADIUS OF 064 KT WINDS - 025 NM NORTHEAST QUADRANT 025 NM SOUTHEAST QUADRANT 025 NM SOUTHWEST QUADRANT 025 NM NORTHWEST QUADRANT RADIUS OF 050 KT WINDS - 040 NM NORTHEAST QUADRANT 045 NM SOUTHEAST QUADRANT 045 NM SOUTHWEST QUADRANT 040 NM NORTHWEST QUADRANT RADIUS OF 034 KT WINDS - 100 NM NORTHEAST QUADRANT 110 NM SOUTHEAST QUADRANT 110 NM SOUTHWEST QUADRANT 100 NM NORTHWEST QUADRANT VECTOR TO 96 HR POSIT: 215 DEG/ 06 KTS --- LONG RANGE OUTLOOK: --- 96 HRS, VALID AT: 011800Z --- 17.2S 75.6E MAX SUSTAINED WINDS - 075 KT, GUSTS 090 KT WIND RADII VALID OVER OPEN WATER ONLY VECTOR TO 120 HR POSIT: 235 DEG/ 08 KTS --- 120 HRS, VALID AT: 021800Z --- 19.0S 72.8E MAX SUSTAINED WINDS - 055 KT, GUSTS 070 KT WIND RADII VALID OVER OPEN WATER ONLY --- REMARKS: 282100Z POSITION NEAR 12.5S 86.6E. TROPICAL CYCLONE (TC) 04S, LOCATED APPROXIMATELY 920 NM EAST- SOUTHEAST OF DIEGO GARCIA, HAS TRACKED WEST-SOUTHWESTWARD AT 13 KNOTS OVER THE PAST SIX HOURS. THE CURRENT POSITION IS BASED ON RECENT FIXES FROM KNES AND PGTW AND A 281547Z METOP-A MICROWAVE SATELLITE PASS. THE CURRENT INTENSITY ESTIMATE IS BASED ON DVORAK T- NUMBER VALUES OF 2.5 FROM BOTH KNES AND PGTW. TC 04S IS TRACKING ALONG THE NORTHWESTERN PERIPHERY OF A DEEP SUBTROPICAL STEERING RIDGE POSITIONED TO THE SOUTHEAST. THE DEEPEST CONVECTION REMAINS ALONG THE WESTERN PERIPHERY OF THE SYSTEM, WHICH LIES IN AN AREA OF MODERATE SHEAR INDUCED BY THE PERIPHERAL FLOW AROUND AN UPPER-LEVEL ANTICYCLONE CENTERED TO THE SOUTHEAST. OVER THE NEXT 48 HOURS, TC 04S IS EXPECTED TO CONTINUE TRACKING GENERALLY WESTWARD TO WEST- SOUTHWESTWARD UNDER THE INFLUENCE OF THE CURRENT SUBTROPICAL STEERING RIDGE. THEREAFTER, A MID-LATITUDE TROUGH APPROACHING FROM THE SOUTHWEST WILL WEAKEN THE RIDGE AND INDUCE A POLEWARD TURN. BETWEEN TAU 36 AND TAU 48, TC 04S SHOULD MOVE INTO AN AREA OF LOW VERTICAL WIND SHEAR BENEATH THE UPPER-LEVEL RIDGE AXIS. POLEWARD OUTFLOW WILL INCREASE SIGNIFICANTLY DURING THIS PERIOD AS THE SYSTEM BEGINS TO INTERACT WITH THE AFOREMENTIONED TROUGH. A COMBINATION OF DECREASING VERTICAL WIND SHEAR AND IMPROVING OUTFLOW WILL CAUSE TC 04S TO INTENSIFY SIGNIFICANTLY BETWEEN TAU 24 AND TAU 72. THEREAFTER, RIDGING WILL BUILD TO THE SOUTH OF THE SYSTEM IN THE WAKE OF THE MID-LATITUDE TROUGH, STEERING THE CYCLONE BACK TO THE WEST. AN INCREASE IN VERTICAL WIND SHEAR, RESTRICTION OF UPPER-LEVEL OUTFLOW, AND THE INTRODUCTION OF SUBSIDENCE ALOFT ASSOCIATED WITH A RESIDUAL UPPER-LEVEL LOW ARE THEN EXPECTED TO INDUCE STEADY WEAKENING. THE NUMERICAL MODEL GUIDANCE IS IN FAIR AGREEMENT WITH THE CURRENT FORECAST. MAXIMUM SIGNIFICANT WAVE HEIGHT AT 281800Z IS 10 FEET. NEXT WARNINGS AT 290900Z AND 292100Z.// ========================================================================= WTXS32 PGTW 20111229 09:00z MSGID/GENADMIN/NAVMARFCSTCEN PEARL HARBOR HI/JTWC// SUBJ/TROPICAL CYCLONE 04S (FOUR) WARNING NR 003// RMKS/ 1. TROPICAL CYCLONE 04S (FOUR) WARNING NR 003 01 ACTIVE TROPICAL CYCLONE IN SOUTHIO MAX SUSTAINED WINDS BASED ON ONE-MINUTE AVERAGE WIND RADII VALID OVER OPEN WATER ONLY --- WARNING POSITION: 290600Z --- NEAR 12.7S 85.5E MOVEMENT PAST SIX HOURS - 265 DEGREES AT 10 KTS POSITION ACCURATE TO WITHIN 040 NM POSITION BASED ON CENTER LOCATED BY SATELLITE PRESENT WIND DISTRIBUTION: MAX SUSTAINED WINDS - 035 KT, GUSTS 045 KT WIND RADII VALID OVER OPEN WATER ONLY REPEAT POSIT: 12.7S 85.5E --- FORECASTS: 12 HRS, VALID AT: 291800Z --- 12.8S 82.8E MAX SUSTAINED WINDS - 035 KT, GUSTS 045 KT WIND RADII VALID OVER OPEN WATER ONLY VECTOR TO 24 HR POSIT: 260 DEG/ 11 KTS --- 24 HRS, VALID AT: 300600Z --- 13.1S 80.6E MAX SUSTAINED WINDS - 040 KT, GUSTS 050 KT WIND RADII VALID OVER OPEN WATER ONLY RADIUS OF 034 KT WINDS - 050 NM NORTHEAST QUADRANT 060 NM SOUTHEAST QUADRANT 060 NM SOUTHWEST QUADRANT 050 NM NORTHWEST QUADRANT VECTOR TO 36 HR POSIT: 250 DEG/ 08 KTS --- 36 HRS, VALID AT: 301800Z --- 13.7S 79.0E MAX SUSTAINED WINDS - 050 KT, GUSTS 065 KT WIND RADII VALID OVER OPEN WATER ONLY RADIUS OF 034 KT WINDS - 060 NM NORTHEAST QUADRANT 070 NM SOUTHEAST QUADRANT 070 NM SOUTHWEST QUADRANT 060 NM NORTHWEST QUADRANT VECTOR TO 48 HR POSIT: 235 DEG/ 07 KTS --- EXTENDED OUTLOOK: 48 HRS, VALID AT: 310600Z --- 14.5S 77.8E MAX SUSTAINED WINDS - 065 KT, GUSTS 080 KT WIND RADII VALID OVER OPEN WATER ONLY RADIUS OF 050 KT WINDS - 030 NM NORTHEAST QUADRANT 035 NM SOUTHEAST QUADRANT 035 NM SOUTHWEST QUADRANT 030 NM NORTHWEST QUADRANT RADIUS OF 034 KT WINDS - 075 NM NORTHEAST QUADRANT 085 NM SOUTHEAST QUADRANT 085 NM SOUTHWEST QUADRANT 075 NM NORTHWEST QUADRANT VECTOR TO 72 HR POSIT: 220 DEG/ 06 KTS --- 72 HRS, VALID AT: 010600Z --- 16.4S 76.0E MAX SUSTAINED WINDS - 090 KT, GUSTS 110 KT WIND RADII VALID OVER OPEN WATER ONLY RADIUS OF 064 KT WINDS - 025 NM NORTHEAST QUADRANT 025 NM SOUTHEAST QUADRANT 025 NM SOUTHWEST QUADRANT 025 NM NORTHWEST QUADRANT RADIUS OF 050 KT WINDS - 040 NM NORTHEAST QUADRANT 045 NM SOUTHEAST QUADRANT 045 NM SOUTHWEST QUADRANT 040 NM NORTHWEST QUADRANT RADIUS OF 034 KT WINDS - 100 NM NORTHEAST QUADRANT 110 NM SOUTHEAST QUADRANT 110 NM SOUTHWEST QUADRANT 100 NM NORTHWEST QUADRANT VECTOR TO 96 HR POSIT: 210 DEG/ 05 KTS --- LONG RANGE OUTLOOK: --- 96 HRS, VALID AT: 020600Z --- 18.1S 74.9E MAX SUSTAINED WINDS - 075 KT, GUSTS 090 KT WIND RADII VALID OVER OPEN WATER ONLY VECTOR TO 120 HR POSIT: 220 DEG/ 04 KTS --- 120 HRS, VALID AT: 030600Z --- 19.4S 73.7E MAX SUSTAINED WINDS - 055 KT, GUSTS 070 KT WIND RADII VALID OVER OPEN WATER ONLY --- REMARKS: 290900Z POSITION NEAR 12.7S 84.8E. TROPICAL CYCLONE (TC) 04S, LOCATED APPROXIMATELY 830 NM EAST- SOUTHEAST OF DIEGO GARCIA, HAS TRACKED WESTWARD AT 10 KNOTS OVER THE PAST SIX HOURS. ANIMATED MULTISPECTRAL SATELLITE IMAGERY (MSI) DEPICTS A PARTIALLY-EXPOSED LOW-LEVEL CIRCULATION CENTER (LLCC) WITH THE BULK OF THE DEEP CONVECTION CONFINED TO THE WESTERN SEMI-CIRCLE DUE TO MODERATE, EASTERLY VERTICAL WIND SHEAR (VWS). OVER THE PAST 12 HOURS, THERE HAS BEEN A SLIGHT INCREASE IN ORGANIZATION WITH MULTIPLE CONVECTIVE BANDS WRAPPING WEAKLY INTO THE CENTER. A 282347Z CORIOLIS IMAGE DEPICTED A BROAD LLCC WITH TIGHTLY-CURVED SHALLOW BANDING AND RECENT ASCAT SHOWS A BROAD WIND FIELD WITH 20-25 KNOT WINDS AROUND THE PERIPHERY. THE UPPER-LEVEL ENVIRONMENT REMAINS MARGINAL DUE TO THE POSITION OF THE ANTICYCLONE TO THE SOUTHEAST, WHICH IS PRODUCING THE MODERATE VWS. BASED ON THE BROAD LLCC AND MARGINAL ENVIRONMENT, THE SYSTEM IS EXPECTED TO INTENSIFY SLOWLY THROUGH TAU 36. THERE IS GOOD CONFIDENCE IN THE CURRENT POSITION AND THE CURRENT INTENSITY IS BASED ON DVORAK ESTIMATES OF 35 KNOTS FROM KNES AND PGTW. TC 04S IS FORECAST TO TRACK WESTWARD TO WEST- SOUTHWESTWARD THROUGH TAU 36 UNDER THE LOW-LEVEL SUBTROPICAL RIDGE (STR) POSITIONED SOUTH. AFTER TAU 36, TC 04S IS EXPECTED TO TURN SOUTHWESTWARD TOWARD A WEAKNESS IN THE STR CREATED BY AN APPROACHING, DEEP MIDLATITUDE SHORTWAVE TROUGH, WHICH WILL LEAD TO A DECREASE IN VWS AND IMPROVED POLEWARD OUTFLOW. THEREFORE, THE SYSTEM IS FORECAST TO INTENSIFY AT A FASTER RATE TO A PEAK INTENSITY OF 90 KNOTS BY TAU 72. MODEL GUIDANCE IS IN TIGHT AGREEMENT THROUGH TAU 72. IN THE EXTENDED PERIOD, TC 04S WILL SLOW AS IT ENCOUNTERS INCREASING VWS AND CONVERGENCE ALOFT ASSOCIATED WITH THE AFOREMENTIONED TROUGH AND WILL WEAKEN. MODEL GUIDANCE DIVERGES AFTER TAU 72 WITH INCREASED UNCERTAINTY IN THE TRACK. MAXIMUM SIGNIFICANT WAVE HEIGHT AT 290600Z IS 15 FEET. NEXT WARNINGS AT 292100Z AND 300900Z.// ========================================================================= WTXS32 PGTW 20111229 21:00z MSGID/GENADMIN/NAVMARFCSTCEN PEARL HARBOR HI/JTWC// SUBJ/TROPICAL CYCLONE 04S (FOUR) WARNING NR 004// RMKS/ 1. TROPICAL CYCLONE 04S (FOUR) WARNING NR 004 01 ACTIVE TROPICAL CYCLONE IN SOUTHIO MAX SUSTAINED WINDS BASED ON ONE-MINUTE AVERAGE WIND RADII VALID OVER OPEN WATER ONLY --- WARNING POSITION: 291800Z --- NEAR 13.2S 82.6E MOVEMENT PAST SIX HOURS - 255 DEGREES AT 15 KTS POSITION ACCURATE TO WITHIN 060 NM POSITION BASED ON CENTER LOCATED BY SATELLITE PRESENT WIND DISTRIBUTION: MAX SUSTAINED WINDS - 040 KT, GUSTS 050 KT WIND RADII VALID OVER OPEN WATER ONLY RADIUS OF 034 KT WINDS - 050 NM NORTHEAST QUADRANT 060 NM SOUTHEAST QUADRANT 060 NM SOUTHWEST QUADRANT 050 NM NORTHWEST QUADRANT REPEAT POSIT: 13.2S 82.6E --- FORECASTS: 12 HRS, VALID AT: 300600Z --- 13.5S 80.2E MAX SUSTAINED WINDS - 050 KT, GUSTS 065 KT WIND RADII VALID OVER OPEN WATER ONLY RADIUS OF 034 KT WINDS - 060 NM NORTHEAST QUADRANT 070 NM SOUTHEAST QUADRANT 070 NM SOUTHWEST QUADRANT 060 NM NORTHWEST QUADRANT VECTOR TO 24 HR POSIT: 250 DEG/ 10 KTS --- 24 HRS, VALID AT: 301800Z --- 14.1S 78.3E MAX SUSTAINED WINDS - 060 KT, GUSTS 075 KT WIND RADII VALID OVER OPEN WATER ONLY RADIUS OF 050 KT WINDS - 030 NM NORTHEAST QUADRANT 035 NM SOUTHEAST QUADRANT 035 NM SOUTHWEST QUADRANT 030 NM NORTHWEST QUADRANT RADIUS OF 034 KT WINDS - 075 NM NORTHEAST QUADRANT 085 NM SOUTHEAST QUADRANT 085 NM SOUTHWEST QUADRANT 075 NM NORTHWEST QUADRANT VECTOR TO 36 HR POSIT: 235 DEG/ 08 KTS --- 36 HRS, VALID AT: 310600Z --- 15.0S 77.0E MAX SUSTAINED WINDS - 070 KT, GUSTS 085 KT WIND RADII VALID OVER OPEN WATER ONLY RADIUS OF 064 KT WINDS - 020 NM NORTHEAST QUADRANT 020 NM SOUTHEAST QUADRANT 020 NM SOUTHWEST QUADRANT 020 NM NORTHWEST QUADRANT RADIUS OF 050 KT WINDS - 035 NM NORTHEAST QUADRANT 040 NM SOUTHEAST QUADRANT 040 NM SOUTHWEST QUADRANT 035 NM NORTHWEST QUADRANT RADIUS OF 034 KT WINDS - 085 NM NORTHEAST QUADRANT 095 NM SOUTHEAST QUADRANT 095 NM SOUTHWEST QUADRANT 085 NM NORTHWEST QUADRANT VECTOR TO 48 HR POSIT: 215 DEG/ 08 KTS --- EXTENDED OUTLOOK: 48 HRS, VALID AT: 311800Z --- 16.3S 76.1E MAX SUSTAINED WINDS - 090 KT, GUSTS 110 KT WIND RADII VALID OVER OPEN WATER ONLY RADIUS OF 064 KT WINDS - 025 NM NORTHEAST QUADRANT 025 NM SOUTHEAST QUADRANT 025 NM SOUTHWEST QUADRANT 025 NM NORTHWEST QUADRANT RADIUS OF 050 KT WINDS - 030 NM NORTHEAST QUADRANT 035 NM SOUTHEAST QUADRANT 035 NM SOUTHWEST QUADRANT 030 NM NORTHWEST QUADRANT RADIUS OF 034 KT WINDS - 100 NM NORTHEAST QUADRANT 110 NM SOUTHEAST QUADRANT 110 NM SOUTHWEST QUADRANT 100 NM NORTHWEST QUADRANT VECTOR TO 72 HR POSIT: 220 DEG/ 07 KTS --- 72 HRS, VALID AT: 011800Z --- 18.5S 74.2E MAX SUSTAINED WINDS - 085 KT, GUSTS 105 KT WIND RADII VALID OVER OPEN WATER ONLY RADIUS OF 064 KT WINDS - 025 NM NORTHEAST QUADRANT 025 NM SOUTHEAST QUADRANT 025 NM SOUTHWEST QUADRANT 025 NM NORTHWEST QUADRANT RADIUS OF 050 KT WINDS - 040 NM NORTHEAST QUADRANT 045 NM SOUTHEAST QUADRANT 045 NM SOUTHWEST QUADRANT 040 NM NORTHWEST QUADRANT RADIUS OF 034 KT WINDS - 095 NM NORTHEAST QUADRANT 105 NM SOUTHEAST QUADRANT 105 NM SOUTHWEST QUADRANT 095 NM NORTHWEST QUADRANT VECTOR TO 96 HR POSIT: 235 DEG/ 06 KTS --- LONG RANGE OUTLOOK: --- 96 HRS, VALID AT: 021800Z --- 19.8S 72.3E MAX SUSTAINED WINDS - 075 KT, GUSTS 090 KT WIND RADII VALID OVER OPEN WATER ONLY VECTOR TO 120 HR POSIT: 265 DEG/ 05 KTS --- 120 HRS, VALID AT: 031800Z --- 20.0S 70.0E MAX SUSTAINED WINDS - 055 KT, GUSTS 070 KT WIND RADII VALID OVER OPEN WATER ONLY --- REMARKS: 292100Z POSITION NEAR 13.3S 82.0E. TROPICAL CYCLONE (TC) 04S, LOCATED APPROXIMATELY 680 NM EAST- SOUTHEAST OF DIEGO GARCIA, HAD TRACKED WEST-SOUTHWESTWARD AT 15 KNOTS OVER THE PAST SIX HOURS. ANIMATED INFRARED (IR) SATELLITE IMAGERY DEPICTS CONSOLIDATING CONVECTION OVER THE LOW-LEVEL CIRCULATION CENTER (LLCC) WITH AN INCREASE IN SYMMETRY. THE CURRENT POSITION IS BASED ON THE PGTW CENTER FIX WITH LOW CONFIDENCE DUE TO THE CLOUD COVER OVER THE LLCC IN THE IR IMAGERY. THE CURRENT INTENSITY IS AN AVERAGE VALUE OF THE DVORAK ESTIMATES RANGING FROM 35-55 KNOTS. UPPER-LEVEL ANALYSIS INDICATES THAT TC 04S IS A FEW DEGREES EQUATORWARD OF THE SUBTROPICAL RIDGE AXIS IN AN AREA OF MODERATE (20-KNOT) EASTERLY VERTICAL WIND SHEAR (VWS) WITH EXCELLENT DIVERGENCE ALOFT. RECENT ANIMATED WATER VAPOR IMAGERY SHOWS GOOD RADIAL OUTFLOW WHICH SEEMS TO BE OVERCOMING THE VWS. TC 04S IS FORECAST TO TRACK WEST-SOUTHWESTWARD THROUGH TAU 36 UNDER THE MID TO UPPER-LEVEL SUBTROPICAL RIDGE (STR) POSITIONED SOUTH. AFTER TAU 36, TC 04S IS EXPECTED TO TURN SOUTHWESTWARD TOWARD A WEAKNESS IN THE SUBTROPICAL RIDGE CREATED BY AN APPROACHING, DEEP MIDLATITUDE SHORTWAVE TROUGH, WHICH WILL LEAD TO A DECREASE IN VWS AND IMPROVED POLEWARD OUTFLOW. THEREFORE, THE SYSTEM IS FORECAST TO INTENSIFY AT A FASTER RATE TO A PEAK INTENSITY OF 90 KNOTS BY TAU 48. MODEL GUIDANCE IS IN TIGHT AGREEMENT THROUGH TAU 72. IN THE EXTENDED PERIOD, TC 04S WILL SLOW AS IT ENCOUNTERS INCREASING VWS AND CONVERGENCE ALOFT ASSOCIATED WITH THE AFOREMENTIONED TROUGH AND WILL BEGIN TO WEAKEN. MODEL GUIDANCE DIVERGES AFTER TAU 72 WITH INCREASED UNCERTAINTY IN THE TRACK. THIS FORECAST FAVORS THE MORE WESTWARD TRACK UNDER THE STEERING INFLUENCE OF A RE-BUILDING SUBTROPICAL RIDGE AS THE MID-LATITUDE TROUGH PROPAGATES OUT OF THE AREA. MAXIMUM SIGNIFICANT WAVE HEIGHT AT 291800Z IS 18 FEET. NEXT WARNINGS AT 300900Z AND 302100Z.// ========================================================================= WTXS32 PGTW 20111230 09:00z MSGID/GENADMIN/NAVMARFCSTCEN PEARL HARBOR HI/JTWC// SUBJ/TROPICAL CYCLONE 04S (BENILDE) WARNING NR 005// RMKS/ 1. TROPICAL CYCLONE 04S (BENILDE) WARNING NR 005 01 ACTIVE TROPICAL CYCLONE IN SOUTHIO MAX SUSTAINED WINDS BASED ON ONE-MINUTE AVERAGE WIND RADII VALID OVER OPEN WATER ONLY --- WARNING POSITION: 300600Z --- NEAR 13.3S 79.5E MOVEMENT PAST SIX HOURS - 265 DEGREES AT 15 KTS POSITION ACCURATE TO WITHIN 060 NM POSITION BASED ON CENTER LOCATED BY SATELLITE PRESENT WIND DISTRIBUTION: MAX SUSTAINED WINDS - 050 KT, GUSTS 065 KT WIND RADII VALID OVER OPEN WATER ONLY RADIUS OF 034 KT WINDS - 050 NM NORTHEAST QUADRANT 060 NM SOUTHEAST QUADRANT 060 NM SOUTHWEST QUADRANT 050 NM NORTHWEST QUADRANT REPEAT POSIT: 13.3S 79.5E --- FORECASTS: 12 HRS, VALID AT: 301800Z --- 13.6S 77.7E MAX SUSTAINED WINDS - 050 KT, GUSTS 065 KT WIND RADII VALID OVER OPEN WATER ONLY RADIUS OF 034 KT WINDS - 050 NM NORTHEAST QUADRANT 060 NM SOUTHEAST QUADRANT 060 NM SOUTHWEST QUADRANT 050 NM NORTHWEST QUADRANT VECTOR TO 24 HR POSIT: 245 DEG/ 06 KTS --- 24 HRS, VALID AT: 310600Z --- 14.1S 76.5E MAX SUSTAINED WINDS - 060 KT, GUSTS 075 KT WIND RADII VALID OVER OPEN WATER ONLY RADIUS OF 050 KT WINDS - 030 NM NORTHEAST QUADRANT 035 NM SOUTHEAST QUADRANT 035 NM SOUTHWEST QUADRANT 030 NM NORTHWEST QUADRANT RADIUS OF 034 KT WINDS - 075 NM NORTHEAST QUADRANT 085 NM SOUTHEAST QUADRANT 085 NM SOUTHWEST QUADRANT 075 NM NORTHWEST QUADRANT VECTOR TO 36 HR POSIT: 225 DEG/ 05 KTS --- 36 HRS, VALID AT: 311800Z --- 14.8S 75.8E MAX SUSTAINED WINDS - 070 KT, GUSTS 085 KT WIND RADII VALID OVER OPEN WATER ONLY RADIUS OF 064 KT WINDS - 020 NM NORTHEAST QUADRANT 020 NM SOUTHEAST QUADRANT 020 NM SOUTHWEST QUADRANT 020 NM NORTHWEST QUADRANT RADIUS OF 050 KT WINDS - 035 NM NORTHEAST QUADRANT 040 NM SOUTHEAST QUADRANT 040 NM SOUTHWEST QUADRANT 035 NM NORTHWEST QUADRANT RADIUS OF 034 KT WINDS - 085 NM NORTHEAST QUADRANT 095 NM SOUTHEAST QUADRANT 095 NM SOUTHWEST QUADRANT 085 NM NORTHWEST QUADRANT VECTOR TO 48 HR POSIT: 215 DEG/ 05 KTS --- EXTENDED OUTLOOK: 48 HRS, VALID AT: 010600Z --- 15.6S 75.2E MAX SUSTAINED WINDS - 085 KT, GUSTS 105 KT WIND RADII VALID OVER OPEN WATER ONLY RADIUS OF 064 KT WINDS - 025 NM NORTHEAST QUADRANT 025 NM SOUTHEAST QUADRANT 025 NM SOUTHWEST QUADRANT 025 NM NORTHWEST QUADRANT RADIUS OF 050 KT WINDS - 040 NM NORTHEAST QUADRANT 045 NM SOUTHEAST QUADRANT 045 NM SOUTHWEST QUADRANT 040 NM NORTHWEST QUADRANT RADIUS OF 034 KT WINDS - 100 NM NORTHEAST QUADRANT 110 NM SOUTHEAST QUADRANT 110 NM SOUTHWEST QUADRANT 100 NM NORTHWEST QUADRANT VECTOR TO 72 HR POSIT: 215 DEG/ 04 KTS --- 72 HRS, VALID AT: 020600Z --- 17.0S 74.1E MAX SUSTAINED WINDS - 085 KT, GUSTS 105 KT WIND RADII VALID OVER OPEN WATER ONLY RADIUS OF 064 KT WINDS - 025 NM NORTHEAST QUADRANT 025 NM SOUTHEAST QUADRANT 025 NM SOUTHWEST QUADRANT 025 NM NORTHWEST QUADRANT RADIUS OF 050 KT WINDS - 040 NM NORTHEAST QUADRANT 045 NM SOUTHEAST QUADRANT 045 NM SOUTHWEST QUADRANT 040 NM NORTHWEST QUADRANT RADIUS OF 034 KT WINDS - 095 NM NORTHEAST QUADRANT 105 NM SOUTHEAST QUADRANT 105 NM SOUTHWEST QUADRANT 095 NM NORTHWEST QUADRANT VECTOR TO 96 HR POSIT: 235 DEG/ 05 KTS --- LONG RANGE OUTLOOK: --- 96 HRS, VALID AT: 030600Z --- 18.3S 72.3E MAX SUSTAINED WINDS - 075 KT, GUSTS 090 KT WIND RADII VALID OVER OPEN WATER ONLY VECTOR TO 120 HR POSIT: 245 DEG/ 05 KTS --- 120 HRS, VALID AT: 040600Z --- 19.2S 70.4E MAX SUSTAINED WINDS - 055 KT, GUSTS 070 KT WIND RADII VALID OVER OPEN WATER ONLY --- REMARKS: 300900Z POSITION NEAR 13.4S 79.0E. TROPICAL CYCLONE (TC) 04S (BENILDE), LOCATED APPROXIMATELY 545 NM SOUTHEAST OF DIEGO GARCIA, HAS TRACKED JUST SOUTH OF WESTWARD AT 15 KNOTS OVER THE PAST SIX HOURS. ANIMATED MULTISPECTRAL SATELLITE IMAGERY SHOWS THE CYCLONE HAS MAINTAINED CONVECTIVE BANDING AND ORGANIZATION. THE INITIAL POSITION WAS BASED ON THE ABOVE ANIMATION AND FROM A 300413Z METOPA MICROWAVE IMAGE. THE INITIAL INTENSITY WAS BASED FROM DVORAK ESTIMATES FROM PGTW, KNES, AND FMEE. UPPER LEVEL ANALYSIS INDICATES TC 04S IS JUST TO THE NORTH OF A RIDGE AXIS IN AN AREA OF MODERATE (15-20 KNOT) EASTERLY VERTICAL WIND SHEAR. IT IS TRACKING ALONG THE NORTHWEST PERIPHERY OF A DEEP-LAYERED SUBTROPICAL RIDGE TO THE SOUTHEAST. THE SYSTEM IS EXPECTED TO TRACK MORE SOUTHWESTWARD AFTER TAU 24 IN RESPONSE TO AN APPROACHING MID- LATITUDE TROUGH APPROACHING FROM THE SOUTHWEST. AFTER TAU 48, TC BENILDE IS EXPECTED TO VEER ON A MORE WESTWARD TRACK AS A SECONDARY RIDGE BEHIND THE TROUGH ASSUMES STEERING. THE AVAILABLE NUMERICAL MODEL GUIDANCE IS IN FAIR AGREEMENT WITH THE EGRR AS THE LEFTMOST OUTLIER, FAVORING A SHARP POLEWARD TRACK. THIS TRACK FORECAST IS JUST TO THE RIGHT OF CONSENSUS TO OFFSET EGRR. MAXIMUM SIGNIFICANT WAVE HEIGHT AT 300600Z IS 18 FEET. NEXT WARNINGS AT 302100Z AND 310900Z.// ========================================================================= WTXS32 PGTW 201112130 21:00z MSGID/GENADMIN/NAVMARFCSTCEN PEARL HARBOR HI/JTWC// SUBJ/TROPICAL CYCLONE 04S (BENILDE) WARNING NR 006// RMKS/ 1. TROPICAL CYCLONE 04S (BENILDE) WARNING NR 006 01 ACTIVE TROPICAL CYCLONE IN SOUTHIO MAX SUSTAINED WINDS BASED ON ONE-MINUTE AVERAGE WIND RADII VALID OVER OPEN WATER ONLY --- WARNING POSITION: 301800Z --- NEAR 13.7S 77.9E MOVEMENT PAST SIX HOURS - 255 DEGREES AT 07 KTS POSITION ACCURATE TO WITHIN 060 NM POSITION BASED ON CENTER LOCATED BY SATELLITE PRESENT WIND DISTRIBUTION: MAX SUSTAINED WINDS - 070 KT, GUSTS 085 KT WIND RADII VALID OVER OPEN WATER ONLY RADIUS OF 064 KT WINDS - 015 NM NORTHEAST QUADRANT 020 NM SOUTHEAST QUADRANT 020 NM SOUTHWEST QUADRANT 015 NM NORTHWEST QUADRANT RADIUS OF 050 KT WINDS - 030 NM NORTHEAST QUADRANT 035 NM SOUTHEAST QUADRANT 035 NM SOUTHWEST QUADRANT 030 NM NORTHWEST QUADRANT RADIUS OF 034 KT WINDS - 065 NM NORTHEAST QUADRANT 075 NM SOUTHEAST QUADRANT 075 NM SOUTHWEST QUADRANT 065 NM NORTHWEST QUADRANT REPEAT POSIT: 13.7S 77.9E --- FORECASTS: 12 HRS, VALID AT: 310600Z --- 14.2S 76.6E MAX SUSTAINED WINDS - 085 KT, GUSTS 105 KT WIND RADII VALID OVER OPEN WATER ONLY RADIUS OF 064 KT WINDS - 020 NM NORTHEAST QUADRANT 025 NM SOUTHEAST QUADRANT 025 NM SOUTHWEST QUADRANT 020 NM NORTHWEST QUADRANT RADIUS OF 050 KT WINDS - 040 NM NORTHEAST QUADRANT 045 NM SOUTHEAST QUADRANT 045 NM SOUTHWEST QUADRANT 040 NM NORTHWEST QUADRANT RADIUS OF 034 KT WINDS - 080 NM NORTHEAST QUADRANT 090 NM SOUTHEAST QUADRANT 090 NM SOUTHWEST QUADRANT 080 NM NORTHWEST QUADRANT VECTOR TO 24 HR POSIT: 245 DEG/ 04 KTS --- 24 HRS, VALID AT: 311800Z --- 14.6S 75.8E MAX SUSTAINED WINDS - 100 KT, GUSTS 125 KT WIND RADII VALID OVER OPEN WATER ONLY RADIUS OF 064 KT WINDS - 025 NM NORTHEAST QUADRANT 030 NM SOUTHEAST QUADRANT 030 NM SOUTHWEST QUADRANT 025 NM NORTHWEST QUADRANT RADIUS OF 050 KT WINDS - 050 NM NORTHEAST QUADRANT 055 NM SOUTHEAST QUADRANT 055 NM SOUTHWEST QUADRANT 050 NM NORTHWEST QUADRANT RADIUS OF 034 KT WINDS - 095 NM NORTHEAST QUADRANT 105 NM SOUTHEAST QUADRANT 105 NM SOUTHWEST QUADRANT 095 NM NORTHWEST QUADRANT VECTOR TO 36 HR POSIT: 215 DEG/ 05 KTS --- 36 HRS, VALID AT: 010600Z --- 15.4S 75.2E MAX SUSTAINED WINDS - 110 KT, GUSTS 135 KT WIND RADII VALID OVER OPEN WATER ONLY RADIUS OF 064 KT WINDS - 035 NM NORTHEAST QUADRANT 040 NM SOUTHEAST QUADRANT 040 NM SOUTHWEST QUADRANT 035 NM NORTHWEST QUADRANT RADIUS OF 050 KT WINDS - 060 NM NORTHEAST QUADRANT 065 NM SOUTHEAST QUADRANT 065 NM SOUTHWEST QUADRANT 060 NM NORTHWEST QUADRANT RADIUS OF 034 KT WINDS - 110 NM NORTHEAST QUADRANT 120 NM SOUTHEAST QUADRANT 120 NM SOUTHWEST QUADRANT 110 NM NORTHWEST QUADRANT VECTOR TO 48 HR POSIT: 195 DEG/ 05 KTS --- EXTENDED OUTLOOK: 48 HRS, VALID AT: 011800Z --- 16.4S 74.9E MAX SUSTAINED WINDS - 115 KT, GUSTS 140 KT WIND RADII VALID OVER OPEN WATER ONLY RADIUS OF 064 KT WINDS - 040 NM NORTHEAST QUADRANT 045 NM SOUTHEAST QUADRANT 045 NM SOUTHWEST QUADRANT 040 NM NORTHWEST QUADRANT RADIUS OF 050 KT WINDS - 065 NM NORTHEAST QUADRANT 070 NM SOUTHEAST QUADRANT 070 NM SOUTHWEST QUADRANT 065 NM NORTHWEST QUADRANT RADIUS OF 034 KT WINDS - 115 NM NORTHEAST QUADRANT 125 NM SOUTHEAST QUADRANT 125 NM SOUTHWEST QUADRANT 115 NM NORTHWEST QUADRANT VECTOR TO 72 HR POSIT: 200 DEG/ 04 KTS --- 72 HRS, VALID AT: 021800Z --- 17.8S 74.3E MAX SUSTAINED WINDS - 095 KT, GUSTS 115 KT WIND RADII VALID OVER OPEN WATER ONLY RADIUS OF 064 KT WINDS - 025 NM NORTHEAST QUADRANT 030 NM SOUTHEAST QUADRANT 030 NM SOUTHWEST QUADRANT 025 NM NORTHWEST QUADRANT RADIUS OF 050 KT WINDS - 045 NM NORTHEAST QUADRANT 050 NM SOUTHEAST QUADRANT 050 NM SOUTHWEST QUADRANT 045 NM NORTHWEST QUADRANT RADIUS OF 034 KT WINDS - 090 NM NORTHEAST QUADRANT 100 NM SOUTHEAST QUADRANT 100 NM SOUTHWEST QUADRANT 090 NM NORTHWEST QUADRANT VECTOR TO 96 HR POSIT: 240 DEG/ 05 KTS --- LONG RANGE OUTLOOK: --- 96 HRS, VALID AT: 031800Z --- 18.8S 72.3E MAX SUSTAINED WINDS - 080 KT, GUSTS 100 KT WIND RADII VALID OVER OPEN WATER ONLY VECTOR TO 120 HR POSIT: 255 DEG/ 05 KTS --- 120 HRS, VALID AT: 041800Z --- 19.4S 70.1E MAX SUSTAINED WINDS - 075 KT, GUSTS 090 KT WIND RADII VALID OVER OPEN WATER ONLY --- REMARKS: 302100Z POSITION NEAR 13.8S 77.6E. TROPICAL CYCLONE (TC) 04S (BENILDE), LOCATED APPROXIMATELY 480 NM SOUTHEAST OF DIEGO GARCIA, HAD TRACKED WEST-SOUTHWESTWARD AT 07 KNOTS OVER THE PAST SIX HOURS. ANIMATED INFRARED SATELLITE IMAGERY (IR) SHOWS SYMMETRIC SPIRAL BANDING AROUND THE LOW-LEVEL CIRCULATION CENTER (LLCC). A 301517Z SSMIS 91 GHZ IMAGE SHOWS DEEP SPIRAL BANDING ENCOMPASSING THE MAJORITY OF THE LLCC WITH A SMALL BREAK OVER THE SOUTHWESTERN QUADRANT. TC 04S SEEMS VERY CLOSE TO FORMING A SUSTAINED EYE-FEATURE AS INTENSITIES HAVE SHARPLY INCREASED OVER THE PAST 12-24 HOURS. THE CURRENT POSITION IS BASED ON THE ABOVEMENTIONED IMAGERY WITH FAIR CONFIDENCE AS THERE IS STILL CIRRUS CLOUD COVER FROM THE OVERSHOOTING TOPS COVERING THE LLCC. THE CURRENT INTENSITY IS BASED ON A BLEND OF DVORAK ESTIMATES RANGING FROM 65-77 KNOTS FROM PGTW, KNES, FMEE, AND FIMP, ALONG WITH A SATCON INTENSITY ESTIMATE OF 69 KNOTS. UPPER-LEVEL ANALYSIS INDICATES THAT TC BENILDE IS JUST EQUATORWARD OF THE SUBTROPICAL RIDGE AXIS IN AN AREA OF MODERATE (15-20 KNOT) EASTERLY VERTICAL WIND SHEAR (VWS) AND EXCELLENT DIVERGENCE ALOFT. HOWEVER, RECENT ANIMATED WATER VAPOR IMAGERY SHOWS ABUNDANT RADIAL OUTFLOW WITH A POLEWARD TAP INTO A MID-LATITUDE TROUGH LOCATED TO THE SOUTHWEST. TC 04S IS EXPECTED TO TRACK MORE SOUTHWESTWARD AFTER TAU 24 IN RESPONSE TO THE APPROACHING TROUGH. FROM THE CURRENT TIME OUT TO TAU 48, TC BENILDE WILL FURTHER INTENSIFY AS OUTFLOW BECOMES ENHANCED BY THE PROPAGATING TROUGH. TC 04S SHOULD REACH A MAXIMUM INTENSITY OF 115 KNOTS BY TAU 48. AFTERWARDS, THE SYSTEM SHOULD BEGIN TO SLOWLY SPIN- DOWN DUE TO INCREASING VWS AND BEGIN TO VEER ON A MORE WESTWARD TRACK AS A SECONDARY RIDGE BEHIND THE TROUGH ASSUMES THE STEERING FLOW. NUMERICAL MODEL GUIDANCE IS IN GOOD AGREEMENT OUT TO TAU 36. FROM TAU 48 ONWARDS THERE IS DISCREPANCY ABOUT THE TIMING OF THE TROUGH PASSAGE AND POSSIBLE INTERACTION WITH ANOTHER AREA OF SUBSTANTIAL VORTICITY ASSOCIATED WITH AN INVEST AREA (98S). MODEL GUIDANCE HAS BEEN CONSISTENTLY PORTRAYING SOME KIND OF INTERACTION BETWEEN THE TWO SYSTEMS. THEREFORE, THIS FORECAST IS IN LINE WITH THE MODEL CONSENSUS OUT TO TAU 36. THE EXTENDED FORECAST FAVORS A MORE WESTWARD TRACK AS DEPICTED BY THE GFS. TRACK SPEEDS ARE ALSO FASTER DURING THIS TIME TO OFFSET THE RE-CURVING SCENARIOS DEPICTED BY THE EGRR AND WBAR. MAXIMUM SIGNIFICANT WAVE HEIGHT AT 301800Z IS 20 FEET. NEXT WARNINGS AT 310900Z AND 312100Z.// ========================================================================= WTXS32 PGTW 20111231 09:00z MSGID/GENADMIN/NAVMARFCSTCEN PEARL HARBOR HI/JTWC// SUBJ/TROPICAL CYCLONE 04S (BENILDE) WARNING NR 007// RMKS/ 1. TROPICAL CYCLONE 04S (BENILDE) WARNING NR 007 01 ACTIVE TROPICAL CYCLONE IN SOUTHIO MAX SUSTAINED WINDS BASED ON ONE-MINUTE AVERAGE WIND RADII VALID OVER OPEN WATER ONLY --- WARNING POSITION: 310600Z --- NEAR 14.7S 76.6E MOVEMENT PAST SIX HOURS - 240 DEGREES AT 08 KTS POSITION ACCURATE TO WITHIN 030 NM POSITION BASED ON EYE FIXED BY SATELLITE PRESENT WIND DISTRIBUTION: MAX SUSTAINED WINDS - 090 KT, GUSTS 110 KT WIND RADII VALID OVER OPEN WATER ONLY RADIUS OF 064 KT WINDS - 020 NM NORTHEAST QUADRANT 025 NM SOUTHEAST QUADRANT 025 NM SOUTHWEST QUADRANT 020 NM NORTHWEST QUADRANT RADIUS OF 050 KT WINDS - 040 NM NORTHEAST QUADRANT 045 NM SOUTHEAST QUADRANT 045 NM SOUTHWEST QUADRANT 040 NM NORTHWEST QUADRANT RADIUS OF 034 KT WINDS - 095 NM NORTHEAST QUADRANT 110 NM SOUTHEAST QUADRANT 110 NM SOUTHWEST QUADRANT 095 NM NORTHWEST QUADRANT REPEAT POSIT: 14.7S 76.6E --- FORECASTS: 12 HRS, VALID AT: 311800Z --- 15.7S 75.7E MAX SUSTAINED WINDS - 095 KT, GUSTS 115 KT WIND RADII VALID OVER OPEN WATER ONLY RADIUS OF 064 KT WINDS - 020 NM NORTHEAST QUADRANT 025 NM SOUTHEAST QUADRANT 025 NM SOUTHWEST QUADRANT 020 NM NORTHWEST QUADRANT RADIUS OF 050 KT WINDS - 040 NM NORTHEAST QUADRANT 045 NM SOUTHEAST QUADRANT 045 NM SOUTHWEST QUADRANT 040 NM NORTHWEST QUADRANT RADIUS OF 034 KT WINDS - 095 NM NORTHEAST QUADRANT 110 NM SOUTHEAST QUADRANT 110 NM SOUTHWEST QUADRANT 095 NM NORTHWEST QUADRANT VECTOR TO 24 HR POSIT: 210 DEG/ 06 KTS --- 24 HRS, VALID AT: 010600Z --- 16.7S 75.1E MAX SUSTAINED WINDS - 105 KT, GUSTS 130 KT WIND RADII VALID OVER OPEN WATER ONLY RADIUS OF 064 KT WINDS - 020 NM NORTHEAST QUADRANT 025 NM SOUTHEAST QUADRANT 025 NM SOUTHWEST QUADRANT 020 NM NORTHWEST QUADRANT RADIUS OF 050 KT WINDS - 040 NM NORTHEAST QUADRANT 045 NM SOUTHEAST QUADRANT 045 NM SOUTHWEST QUADRANT 040 NM NORTHWEST QUADRANT RADIUS OF 034 KT WINDS - 100 NM NORTHEAST QUADRANT 120 NM SOUTHEAST QUADRANT 120 NM SOUTHWEST QUADRANT 100 NM NORTHWEST QUADRANT VECTOR TO 36 HR POSIT: 205 DEG/ 06 KTS --- 36 HRS, VALID AT: 011800Z --- 17.7S 74.6E MAX SUSTAINED WINDS - 110 KT, GUSTS 135 KT WIND RADII VALID OVER OPEN WATER ONLY RADIUS OF 064 KT WINDS - 030 NM NORTHEAST QUADRANT 030 NM SOUTHEAST QUADRANT 030 NM SOUTHWEST QUADRANT 030 NM NORTHWEST QUADRANT RADIUS OF 050 KT WINDS - 045 NM NORTHEAST QUADRANT 050 NM SOUTHEAST QUADRANT 050 NM SOUTHWEST QUADRANT 045 NM NORTHWEST QUADRANT RADIUS OF 034 KT WINDS - 105 NM NORTHEAST QUADRANT 125 NM SOUTHEAST QUADRANT 125 NM SOUTHWEST QUADRANT 105 NM NORTHWEST QUADRANT VECTOR TO 48 HR POSIT: 205 DEG/ 05 KTS --- EXTENDED OUTLOOK: 48 HRS, VALID AT: 020600Z --- 18.6S 74.2E MAX SUSTAINED WINDS - 110 KT, GUSTS 135 KT WIND RADII VALID OVER OPEN WATER ONLY RADIUS OF 064 KT WINDS - 030 NM NORTHEAST QUADRANT 030 NM SOUTHEAST QUADRANT 030 NM SOUTHWEST QUADRANT 030 NM NORTHWEST QUADRANT RADIUS OF 050 KT WINDS - 045 NM NORTHEAST QUADRANT 050 NM SOUTHEAST QUADRANT 050 NM SOUTHWEST QUADRANT 045 NM NORTHWEST QUADRANT RADIUS OF 034 KT WINDS - 105 NM NORTHEAST QUADRANT 125 NM SOUTHEAST QUADRANT 125 NM SOUTHWEST QUADRANT 105 NM NORTHWEST QUADRANT VECTOR TO 72 HR POSIT: 205 DEG/ 02 KTS --- 72 HRS, VALID AT: 030600Z --- 19.4S 73.8E MAX SUSTAINED WINDS - 090 KT, GUSTS 110 KT WIND RADII VALID OVER OPEN WATER ONLY RADIUS OF 064 KT WINDS - 020 NM NORTHEAST QUADRANT 025 NM SOUTHEAST QUADRANT 025 NM SOUTHWEST QUADRANT 020 NM NORTHWEST QUADRANT RADIUS OF 050 KT WINDS - 040 NM NORTHEAST QUADRANT 045 NM SOUTHEAST QUADRANT 045 NM SOUTHWEST QUADRANT 040 NM NORTHWEST QUADRANT RADIUS OF 034 KT WINDS - 100 NM NORTHEAST QUADRANT 120 NM SOUTHEAST QUADRANT 120 NM SOUTHWEST QUADRANT 100 NM NORTHWEST QUADRANT VECTOR TO 96 HR POSIT: 235 DEG/ 02 KTS --- LONG RANGE OUTLOOK: --- 96 HRS, VALID AT: 040600Z --- 19.9S 73.1E MAX SUSTAINED WINDS - 065 KT, GUSTS 080 KT WIND RADII VALID OVER OPEN WATER ONLY VECTOR TO 120 HR POSIT: 285 DEG/ 04 KTS --- 120 HRS, VALID AT: 050600Z --- 19.4S 71.4E MAX SUSTAINED WINDS - 045 KT, GUSTS 055 KT WIND RADII VALID OVER OPEN WATER ONLY --- REMARKS: 310900Z POSITION NEAR 15.0S 76.4E. TROPICAL CYCLONE (TC) 04S (BENILDE), LOCATED APPROXIMATELY 510 NM SOUTH-SOUTHEAST OF DIEGO GARCIA, HAD TRACKED WEST-SOUTHWESTWARD AT 08 KNOTS OVER THE PAST SIX HOURS. ANIMATED MULTISPECTRAL SATELLITE IMAGERY INDICATES THAT THE SYSTEM HAS STRENGTHENED SLIGHTLY DURING THE PAST 12 HOURS WITH A 25-NM ROUND EYE EVIDENT. RECENT MICROWAVE IMAGERY, INCLUDING A 310053Z CORIOLIS IMAGE AND A 310228Z SSMIS IMAGE, DEPICTS TIGHTLY CURVED BANDING AND STRONG OVERALL ORGANIZATION. UPPER-LEVEL ANALYSIS INDICATES A STRONG POLEWARD OUTFLOW CHANNEL ENHANCED BY A DEEP UPPER-LEVEL TROUGH APPROACHING FROM THE SOUTHWEST. THERE IS HIGH CONFIDENCE IN THE CURRENT POSITION BASED ON THE VISIBLE EYE. THE CURRENT INTENSITY IS BASED ON DVORAK ESTIMATES OF 90 KNOTS FROM KNES AND PGTW. TC 04S IS TRACKING ALONG THE NORTHWEST PERIPHERY OF A DEEP SUBTROPICAL RIDGE (STR) AND IS FORECAST TO TURN SOUTH-SOUTHWESTWARD ALONG THE WESTERN PERIPHERY OF THE STR WITHIN THE NEXT 24 HOURS, MAINTAINING THIS TRACK THROUGH TAU 96. TC 04S SHOULD CONTINUE TO INTENSIFY DUE TO FAVORABLE CONDITIONS THROUGH TAU 48. THEREAFTER, THE SYSTEM IS EXPECTED TO WEAKEN AS IT ENCOUNTERS INCREASING VERTICAL WIND SHEAR ASSOCIATED WITH THE AFOREMENTIONED TROUGH. IN THE EXTENDED TAUS, TC 04S SHOULD WEAKEN SIGNIFICANTLY AND TRACK WESTWARD UNDER THE STEERING INFLUENCE OF THE LOW-LEVEL STR EXPECTED TO BUILD TO ITS SOUTH. MODEL GUIDANCE IS IN POOR AGREEMENT DUE TO POOR INITIALIZATION OF THE INTENSITY BY BOTH NOGAPS AND UKMO, WHICH THEN EXHIBIT EXCESSIVE INTERACTION WITH A DEVELOPING LOW TO THE NORTHWEST. THE GFS AND ECMWF MODEL INITIALIZATION AND SOUTH-SOUTHWESTWARD TRACK SOLUTIONS APPEAR MORE REALISTIC AND ARE, THEREFORE, FAVORED. MAXIMUM SIGNIFICANT WAVE HEIGHT AT 310600Z IS 25 FEET. NEXT WARNINGS AT 312100Z AND 010900Z.// ========================================================================= WTXS32 PGTW 20111231 21:00z MSGID/GENADMIN/NAVMARFCSTCEN PEARL HARBOR HI/JTWC// SUBJ/TROPICAL CYCLONE 04S (BENILDE) WARNING NR 008// RMKS/ 1. TROPICAL CYCLONE 04S (BENILDE) WARNING NR 008 01 ACTIVE TROPICAL CYCLONE IN SOUTHIO MAX SUSTAINED WINDS BASED ON ONE-MINUTE AVERAGE WIND RADII VALID OVER OPEN WATER ONLY --- WARNING POSITION: 311800Z --- NEAR 15.9S 75.6E MOVEMENT PAST SIX HOURS - 215 DEGREES AT 07 KTS POSITION ACCURATE TO WITHIN 030 NM POSITION BASED ON EYE FIXED BY SATELLITE PRESENT WIND DISTRIBUTION: MAX SUSTAINED WINDS - 090 KT, GUSTS 110 KT WIND RADII VALID OVER OPEN WATER ONLY RADIUS OF 064 KT WINDS - 030 NM NORTHEAST QUADRANT 035 NM SOUTHEAST QUADRANT 035 NM SOUTHWEST QUADRANT 030 NM NORTHWEST QUADRANT RADIUS OF 050 KT WINDS - 045 NM NORTHEAST QUADRANT 050 NM SOUTHEAST QUADRANT 050 NM SOUTHWEST QUADRANT 045 NM NORTHWEST QUADRANT RADIUS OF 034 KT WINDS - 095 NM NORTHEAST QUADRANT 100 NM SOUTHEAST QUADRANT 100 NM SOUTHWEST QUADRANT 095 NM NORTHWEST QUADRANT REPEAT POSIT: 15.9S 75.6E --- FORECASTS: 12 HRS, VALID AT: 010600Z --- 16.8S 75.1E MAX SUSTAINED WINDS - 085 KT, GUSTS 105 KT WIND RADII VALID OVER OPEN WATER ONLY RADIUS OF 064 KT WINDS - 030 NM NORTHEAST QUADRANT 035 NM SOUTHEAST QUADRANT 035 NM SOUTHWEST QUADRANT 030 NM NORTHWEST QUADRANT RADIUS OF 050 KT WINDS - 045 NM NORTHEAST QUADRANT 050 NM SOUTHEAST QUADRANT 050 NM SOUTHWEST QUADRANT 045 NM NORTHWEST QUADRANT RADIUS OF 034 KT WINDS - 090 NM NORTHEAST QUADRANT 095 NM SOUTHEAST QUADRANT 095 NM SOUTHWEST QUADRANT 090 NM NORTHWEST QUADRANT VECTOR TO 24 HR POSIT: 205 DEG/ 05 KTS --- 24 HRS, VALID AT: 011800Z --- 17.7S 74.7E MAX SUSTAINED WINDS - 075 KT, GUSTS 090 KT WIND RADII VALID OVER OPEN WATER ONLY RADIUS OF 064 KT WINDS - 025 NM NORTHEAST QUADRANT 030 NM SOUTHEAST QUADRANT 030 NM SOUTHWEST QUADRANT 025 NM NORTHWEST QUADRANT RADIUS OF 050 KT WINDS - 040 NM NORTHEAST QUADRANT 045 NM SOUTHEAST QUADRANT 045 NM SOUTHWEST QUADRANT 040 NM NORTHWEST QUADRANT RADIUS OF 034 KT WINDS - 085 NM NORTHEAST QUADRANT 090 NM SOUTHEAST QUADRANT 090 NM SOUTHWEST QUADRANT 085 NM NORTHWEST QUADRANT VECTOR TO 36 HR POSIT: 205 DEG/ 05 KTS --- 36 HRS, VALID AT: 020600Z --- 18.6S 74.3E MAX SUSTAINED WINDS - 065 KT, GUSTS 080 KT WIND RADII VALID OVER OPEN WATER ONLY RADIUS OF 050 KT WINDS - 035 NM NORTHEAST QUADRANT 040 NM SOUTHEAST QUADRANT 040 NM SOUTHWEST QUADRANT 035 NM NORTHWEST QUADRANT RADIUS OF 034 KT WINDS - 080 NM NORTHEAST QUADRANT 085 NM SOUTHEAST QUADRANT 085 NM SOUTHWEST QUADRANT 080 NM NORTHWEST QUADRANT VECTOR TO 48 HR POSIT: 210 DEG/ 04 KTS --- EXTENDED OUTLOOK: 48 HRS, VALID AT: 021800Z --- 19.3S 73.9E MAX SUSTAINED WINDS - 055 KT, GUSTS 070 KT WIND RADII VALID OVER OPEN WATER ONLY RADIUS OF 050 KT WINDS - 030 NM NORTHEAST QUADRANT 035 NM SOUTHEAST QUADRANT 035 NM SOUTHWEST QUADRANT 030 NM NORTHWEST QUADRANT RADIUS OF 034 KT WINDS - 075 NM NORTHEAST QUADRANT 080 NM SOUTHEAST QUADRANT 080 NM SOUTHWEST QUADRANT 075 NM NORTHWEST QUADRANT VECTOR TO 72 HR POSIT: 230 DEG/ 02 KTS --- 72 HRS, VALID AT: 031800Z --- 19.8S 73.3E MAX SUSTAINED WINDS - 045 KT, GUSTS 055 KT WIND RADII VALID OVER OPEN WATER ONLY RADIUS OF 034 KT WINDS - 070 NM NORTHEAST QUADRANT 075 NM SOUTHEAST QUADRANT 075 NM SOUTHWEST QUADRANT 070 NM NORTHWEST QUADRANT VECTOR TO 96 HR POSIT: 260 DEG/ 02 KTS --- LONG RANGE OUTLOOK: --- 96 HRS, VALID AT: 041800Z --- 19.9S 72.5E MAX SUSTAINED WINDS - 035 KT, GUSTS 045 KT WIND RADII VALID OVER OPEN WATER ONLY DISSIPATING AS A SIGNIFICANT TROPICAL CYCLONE OVER WATER VECTOR TO 120 HR POSIT: 285 DEG/ 02 KTS --- 120 HRS, VALID AT: 051800Z --- 19.7S 71.8E MAX SUSTAINED WINDS - 030 KT, GUSTS 040 KT WIND RADII VALID OVER OPEN WATER ONLY DISSIPATED AS A SIGNIFICANT TROPICAL CYCLONE OVER WATER --- REMARKS: 312100Z POSITION NEAR 16.1S 75.5E. TROPICAL CYCLONE (TC) 04S (BENILDE), LOCATED APPROXIMATELY 540 NM SOUTH-SOUTHEAST OF DIEGO GARCIA, HAS TRACKED SOUTHWESTWARD AT 07 KNOTS OVER THE PAST SIX HOURS. THE CURRENT POSITION IS BASED ON SATELLITE FIXES FROM VARIOUS REPORTING AGENCIES AND A 311504Z SSMIS PASS. THE INTENSITY OF 90 KNOTS IS CONSISTENT WITH DVORAK CURRENT INTENSITY ESTIMATES FROM PGTW, KNES, AND FMEE. ANIMATED INFRARED SATELLITE IMAGERY SHOWS A SLIGHT DECREASE IN DEEP CONVECTION AROUND AN INCREASINGLY RAGED EYE, SUGGESTING A HALT IN THE INTENSIFICATION TREND. FORECAST INTENSITIES HAVE BEEN REDUCED SIGNIFICANTLY FROM THE PREVIOUS WARNING. THE INTRODUCTION OF DRIER AIR APPEARS TO BE DISRUPTING THE ORGANIZATION OF THE CYCLONE. A RECENT TOTAL PRECIPITABLE WATER LOOP INDICATES THAT TC 04S IS ENTRAINING DRIER AIR WRAPPING INTO THE SYSTEM FROM THE SOUTHWEST, ALTHOUGH A THIN RIBBON OF MOIST, TROPICAL AIR IS ALSO FEEDING INTO THE SYSTEM FROM THE NORTHEAST. THE CYCLONE REMAINS UNDER AN UPPER-LEVEL RIDGE AXIS, WITH LOW VERTICAL WIND SHEAR AND STRONG POLEWARD OUTFLOW AHEAD OF AN APPROACHING UPPER-LEVEL TROUGH TO THE SOUTHWEST. THE SYSTEM IS TURNING POLEWARD UNDER THE STEERING INFLUENCE OF A SUBTROPICAL RIDGE TO THE EAST. GENERALLY SOUTHWESTWARD TO SOUTH-SOUTHWESTWARD MOTION IS EXPECTED TO CONTINUE THROUGH TAU 48 UNDER THE CONTINUED INFLUENCE OF THIS RIDGE. THEREAFTER, STEADY WEAKENING INDUCED BY DRY AIR ENTRAINMENT, PASSAGE OVER WATER WITH DECREASING MIXED LAYER HEAT CONTENT, INCREASING VERTICAL WIND SHEAR, AND SUBSIDENCE ALOFT WILL CAUSE THE SYSTEM TO TURN WESTWARD WITH THE LOW TO MID-LEVEL FLOW. UNDER THE COMBINED NEGATIVE INTENSITY INFLUENCES, THE SYSTEM IS NOW EXPECTED TO DISSIPATE BELOW THE WARNING THRESHOLD INTENSITY OF 35 KNOTS BY TAU 120. MODEL GUIDANCE IS IN FAIR AGREEMENT THROUGH TAU 48 AND DIVERGES THEREAFTER, WITH GFS DEPICTING RECURVATURE, NOGAPS AND GFDN SHOWING A RAPID TRACK TO THE WEST, AND ECMWF SUGGESTING A VERY SLOW WESTWARD TRACK. BECAUSE THE CHANGE IN STEERING INFLUENCES FAVORS A SLOW DOWN IN THE EXTENDED PERIOD, THIS FORECAST IS CONSISTENT WITH THE ECMWF SCENARIO. MAXIMUM SIGNIFICANT WAVE HEIGHT AT 311800Z IS 28 FEET. NEXT WARNINGS AT 010900Z AND 012100Z.// ========================================================================= WTXS32 PGTW 20120101 09:00z 1. TROPICAL CYCLONE 04S (BENILDE) WARNING NR 009 01 ACTIVE TROPICAL CYCLONE IN SOUTHIO MAX SUSTAINED WINDS BASED ON ONE-MINUTE AVERAGE WIND RADII VALID OVER OPEN WATER ONLY --- WARNING POSITION: 010600Z --- NEAR 16.9S 75.1E MOVEMENT PAST SIX HOURS - 195 DEGREES AT 04 KTS POSITION ACCURATE TO WITHIN 060 NM POSITION BASED ON CENTER LOCATED BY SATELLITE PRESENT WIND DISTRIBUTION: MAX SUSTAINED WINDS - 070 KT, GUSTS 085 KT WIND RADII VALID OVER OPEN WATER ONLY RADIUS OF 064 KT WINDS - 030 NM NORTHEAST QUADRANT 035 NM SOUTHEAST QUADRANT 035 NM SOUTHWEST QUADRANT 030 NM NORTHWEST QUADRANT RADIUS OF 050 KT WINDS - 045 NM NORTHEAST QUADRANT 050 NM SOUTHEAST QUADRANT 050 NM SOUTHWEST QUADRANT 045 NM NORTHWEST QUADRANT RADIUS OF 034 KT WINDS - 090 NM NORTHEAST QUADRANT 100 NM SOUTHEAST QUADRANT 100 NM SOUTHWEST QUADRANT 095 NM NORTHWEST QUADRANT REPEAT POSIT: 16.9S 75.1E --- FORECASTS: 12 HRS, VALID AT: 011800Z --- 18.0S 74.4E MAX SUSTAINED WINDS - 065 KT, GUSTS 080 KT WIND RADII VALID OVER OPEN WATER ONLY RADIUS OF 050 KT WINDS - 045 NM NORTHEAST QUADRANT 050 NM SOUTHEAST QUADRANT 050 NM SOUTHWEST QUADRANT 045 NM NORTHWEST QUADRANT RADIUS OF 034 KT WINDS - 090 NM NORTHEAST QUADRANT 095 NM SOUTHEAST QUADRANT 095 NM SOUTHWEST QUADRANT 090 NM NORTHWEST QUADRANT VECTOR TO 24 HR POSIT: 210 DEG/ 05 KTS --- 24 HRS, VALID AT: 020600Z --- 18.9S 73.8E MAX SUSTAINED WINDS - 065 KT, GUSTS 080 KT WIND RADII VALID OVER OPEN WATER ONLY RADIUS OF 050 KT WINDS - 040 NM NORTHEAST QUADRANT 045 NM SOUTHEAST QUADRANT 045 NM SOUTHWEST QUADRANT 040 NM NORTHWEST QUADRANT RADIUS OF 034 KT WINDS - 085 NM NORTHEAST QUADRANT 090 NM SOUTHEAST QUADRANT 090 NM SOUTHWEST QUADRANT 085 NM NORTHWEST QUADRANT VECTOR TO 36 HR POSIT: 230 DEG/ 04 KTS --- 36 HRS, VALID AT: 021800Z --- 19.5S 73.1E MAX SUSTAINED WINDS - 060 KT, GUSTS 075 KT WIND RADII VALID OVER OPEN WATER ONLY RADIUS OF 050 KT WINDS - 035 NM NORTHEAST QUADRANT 040 NM SOUTHEAST QUADRANT 040 NM SOUTHWEST QUADRANT 035 NM NORTHWEST QUADRANT RADIUS OF 034 KT WINDS - 080 NM NORTHEAST QUADRANT 085 NM SOUTHEAST QUADRANT 085 NM SOUTHWEST QUADRANT 080 NM NORTHWEST QUADRANT VECTOR TO 48 HR POSIT: 260 DEG/ 04 KTS --- EXTENDED OUTLOOK: 48 HRS, VALID AT: 030600Z --- 19.6S 72.3E MAX SUSTAINED WINDS - 055 KT, GUSTS 070 KT WIND RADII VALID OVER OPEN WATER ONLY RADIUS OF 050 KT WINDS - 030 NM NORTHEAST QUADRANT 035 NM SOUTHEAST QUADRANT 035 NM SOUTHWEST QUADRANT 030 NM NORTHWEST QUADRANT RADIUS OF 034 KT WINDS - 075 NM NORTHEAST QUADRANT 080 NM SOUTHEAST QUADRANT 080 NM SOUTHWEST QUADRANT 075 NM NORTHWEST QUADRANT VECTOR TO 72 HR POSIT: 275 DEG/ 04 KTS --- 72 HRS, VALID AT: 040600Z --- 19.4S 70.6E MAX SUSTAINED WINDS - 050 KT, GUSTS 065 KT WIND RADII VALID OVER OPEN WATER ONLY RADIUS OF 034 KT WINDS - 070 NM NORTHEAST QUADRANT 075 NM SOUTHEAST QUADRANT 075 NM SOUTHWEST QUADRANT 070 NM NORTHWEST QUADRANT VECTOR TO 96 HR POSIT: 275 DEG/ 04 KTS --- LONG RANGE OUTLOOK: --- 96 HRS, VALID AT: 050600Z --- 19.3S 68.7E MAX SUSTAINED WINDS - 050 KT, GUSTS 065 KT WIND RADII VALID OVER OPEN WATER ONLY VECTOR TO 120 HR POSIT: 260 DEG/ 03 KTS --- 120 HRS, VALID AT: 060600Z --- 19.5S 67.5E MAX SUSTAINED WINDS - 045 KT, GUSTS 055 KT WIND RADII VALID OVER OPEN WATER ONLY --- REMARKS: 010900Z POSITION NEAR 17.2S 74.9E. MAXIMUM SIGNIFICANT WAVE HEIGHT AT 010600Z IS 30 FEET. NEXT WARNINGS AT 012100Z AND 020900Z. ========================================================================= WTXS32 PGTW 20120101 21:00z MSGID/GENADMIN/NAVMARFCSTCEN PEARL HARBOR HI/JTWC// SUBJ/TROPICAL CYCLONE 04S (BENILDE) WARNING NR 010// RMKS/ 1. TROPICAL CYCLONE 04S (BENILDE) WARNING NR 010 01 ACTIVE TROPICAL CYCLONE IN SOUTHIO MAX SUSTAINED WINDS BASED ON ONE-MINUTE AVERAGE WIND RADII VALID OVER OPEN WATER ONLY --- WARNING POSITION: 011800Z --- NEAR 18.6S 74.6E MOVEMENT PAST SIX HOURS - 190 DEGREES AT 09 KTS POSITION ACCURATE TO WITHIN 045 NM POSITION BASED ON EYE FIXED BY SATELLITE PRESENT WIND DISTRIBUTION: MAX SUSTAINED WINDS - 085 KT, GUSTS 105 KT WIND RADII VALID OVER OPEN WATER ONLY RADIUS OF 064 KT WINDS - 035 NM NORTHEAST QUADRANT 035 NM SOUTHEAST QUADRANT 035 NM SOUTHWEST QUADRANT 035 NM NORTHWEST QUADRANT RADIUS OF 050 KT WINDS - 050 NM NORTHEAST QUADRANT 050 NM SOUTHEAST QUADRANT 050 NM SOUTHWEST QUADRANT 050 NM NORTHWEST QUADRANT RADIUS OF 034 KT WINDS - 110 NM NORTHEAST QUADRANT 130 NM SOUTHEAST QUADRANT 130 NM SOUTHWEST QUADRANT 110 NM NORTHWEST QUADRANT REPEAT POSIT: 18.6S 74.6E --- FORECASTS: 12 HRS, VALID AT: 020600Z --- 19.8S 74.1E MAX SUSTAINED WINDS - 075 KT, GUSTS 090 KT WIND RADII VALID OVER OPEN WATER ONLY RADIUS OF 064 KT WINDS - 030 NM NORTHEAST QUADRANT 030 NM SOUTHEAST QUADRANT 030 NM SOUTHWEST QUADRANT 030 NM NORTHWEST QUADRANT RADIUS OF 050 KT WINDS - 045 NM NORTHEAST QUADRANT 045 NM SOUTHEAST QUADRANT 045 NM SOUTHWEST QUADRANT 045 NM NORTHWEST QUADRANT RADIUS OF 034 KT WINDS - 100 NM NORTHEAST QUADRANT 120 NM SOUTHEAST QUADRANT 120 NM SOUTHWEST QUADRANT 100 NM NORTHWEST QUADRANT VECTOR TO 24 HR POSIT: 215 DEG/ 05 KTS --- 24 HRS, VALID AT: 021800Z --- 20.6S 73.5E MAX SUSTAINED WINDS - 065 KT, GUSTS 080 KT WIND RADII VALID OVER OPEN WATER ONLY RADIUS OF 050 KT WINDS - 045 NM NORTHEAST QUADRANT 045 NM SOUTHEAST QUADRANT 045 NM SOUTHWEST QUADRANT 045 NM NORTHWEST QUADRANT RADIUS OF 034 KT WINDS - 090 NM NORTHEAST QUADRANT 110 NM SOUTHEAST QUADRANT 110 NM SOUTHWEST QUADRANT 090 NM NORTHWEST QUADRANT VECTOR TO 36 HR POSIT: 235 DEG/ 04 KTS --- 36 HRS, VALID AT: 030600Z --- 21.1S 72.7E MAX SUSTAINED WINDS - 055 KT, GUSTS 070 KT WIND RADII VALID OVER OPEN WATER ONLY RADIUS OF 050 KT WINDS - 040 NM NORTHEAST QUADRANT 040 NM SOUTHEAST QUADRANT 040 NM SOUTHWEST QUADRANT 040 NM NORTHWEST QUADRANT RADIUS OF 034 KT WINDS - 080 NM NORTHEAST QUADRANT 100 NM SOUTHEAST QUADRANT 100 NM SOUTHWEST QUADRANT 080 NM NORTHWEST QUADRANT VECTOR TO 48 HR POSIT: 270 DEG/ 04 KTS --- EXTENDED OUTLOOK: 48 HRS, VALID AT: 031800Z --- 21.1S 71.8E MAX SUSTAINED WINDS - 050 KT, GUSTS 065 KT WIND RADII VALID OVER OPEN WATER ONLY RADIUS OF 050 KT WINDS - 030 NM NORTHEAST QUADRANT 035 NM SOUTHEAST QUADRANT 035 NM SOUTHWEST QUADRANT 030 NM NORTHWEST QUADRANT RADIUS OF 034 KT WINDS - 075 NM NORTHEAST QUADRANT 080 NM SOUTHEAST QUADRANT 080 NM SOUTHWEST QUADRANT 075 NM NORTHWEST QUADRANT VECTOR TO 72 HR POSIT: 285 DEG/ 05 KTS --- 72 HRS, VALID AT: 041800Z --- 20.6S 69.8E MAX SUSTAINED WINDS - 040 KT, GUSTS 050 KT WIND RADII VALID OVER OPEN WATER ONLY DISSIPATING AS A SIGNIFICANT TROPICAL CYCLONE OVER WATER RADIUS OF 034 KT WINDS - 070 NM NORTHEAST QUADRANT 075 NM SOUTHEAST QUADRANT 075 NM SOUTHWEST QUADRANT 070 NM NORTHWEST QUADRANT VECTOR TO 96 HR POSIT: 290 DEG/ 05 KTS --- LONG RANGE OUTLOOK: --- 96 HRS, VALID AT: 051800Z --- 20.0S 67.9E MAX SUSTAINED WINDS - 030 KT, GUSTS 040 KT WIND RADII VALID OVER OPEN WATER ONLY DISSIPATED AS A SIGNIFICANT TROPICAL CYCLONE OVER WATER --- REMARKS: 012100Z POSITION NEAR 18.9S 74.5E. TROPICAL CYCLONE (TC) 04S (BENILDE), LOCATED APPROXIMATELY 690 NM SOUTH OF DIEGO GARCIA, HAS TRACKED SOUTHWARD AT 09 KNOTS OVER THE PAST SIX HOURS. ANIMATED INFRARED (IR) SATELLITE IMAGERY INDICATES A 9-NM RAGGED EYE WITH DEEP CONVECTION INCREASING IN AREAL EXTENT OVER THE PAST 12 HOURS AND LOCATED PRIMARILY OVER THE WESTERN SEMI- CIRCLE. ANIMATED WATER VAPOR IMAGERY DEPICTS EXCELLENT POLEWARD OUTFLOW ENHANCED BY A DEEP MIDLATITUDE TROUGH TO THE SOUTHWEST. THE CURRENT POSITION IS EXTRAPOLATED FROM A 011452Z SSMIS IMAGE AND THE EYE IN IR IMAGERY. THE CURRENT INTENSITY IS BASED ON DVORAK ESTIMATES OF 90 KNOTS FROM KNES AND PGTW BUT HEDGED LOWER BASED ON A 65 KNOT ESTIMATE FROM FMEE. THE SYSTEM IS TRACKING POLEWARD ALONG THE WESTERN PERIPHERY OF THE DEEP SUBTROPICAL RIDGE (STR) AND IS FORECAST TO CONTINUE TRACKING SOUTHWARD TO SOUTH-SOUTHWESTWARD THROUGH TAU 24. THEREAFTER, TC 04S SHOULD TURN INCREASINGLY WESTWARD UNDER THE STEERING INFLUENCE OF A LOW- TO MID-LEVEL STR EXPECTED TO BUILD IN TO THE SOUTH AFTER PASSAGE OF THE SHORTWAVE TROUGH. MODEL GUIDANCE IS IN GOOD AGREEMENT THROUGH THE FORECAST PERIOD. TC 04S SHOULD STEADILY WEAKEN DUE TO INCREASING VERTICAL WIND SHEAR AND SUBSIDENCE ALOFT ASSOCIATED WITH PERSISTENT UPPER-LEVEL WESTERLY FLOW. THE SYSTEM IS FORECAST TO DISSIPATE OVER WATER BY TAU 96. MAXIMUM SIGNIFICANT WAVE HEIGHT AT 011800Z IS 30 FEET. NEXT WARNINGS AT 020900Z AND 022100Z.// ========================================================================= WTXS32 PGTW 20120102 09:00z MSGID/GENADMIN/NAVMARFCSTCEN PEARL HARBOR HI/JTWC// SUBJ/TROPICAL CYCLONE 04S (BENILDE) WARNING NR 011// RMKS/ 1. TROPICAL CYCLONE 04S (BENILDE) WARNING NR 011 01 ACTIVE TROPICAL CYCLONE IN SOUTHIO MAX SUSTAINED WINDS BASED ON ONE-MINUTE AVERAGE WIND RADII VALID OVER OPEN WATER ONLY --- WARNING POSITION: 020600Z --- NEAR 19.7S 73.9E MOVEMENT PAST SIX HOURS - 170 DEGREES AT 05 KTS POSITION ACCURATE TO WITHIN 060 NM POSITION BASED ON CENTER LOCATED BY SATELLITE PRESENT WIND DISTRIBUTION: MAX SUSTAINED WINDS - 075 KT, GUSTS 090 KT WIND RADII VALID OVER OPEN WATER ONLY RADIUS OF 064 KT WINDS - 035 NM NORTHEAST QUADRANT 035 NM SOUTHEAST QUADRANT 035 NM SOUTHWEST QUADRANT 035 NM NORTHWEST QUADRANT RADIUS OF 050 KT WINDS - 050 NM NORTHEAST QUADRANT 050 NM SOUTHEAST QUADRANT 050 NM SOUTHWEST QUADRANT 050 NM NORTHWEST QUADRANT RADIUS OF 034 KT WINDS - 110 NM NORTHEAST QUADRANT 130 NM SOUTHEAST QUADRANT 130 NM SOUTHWEST QUADRANT 110 NM NORTHWEST QUADRANT REPEAT POSIT: 19.7S 73.9E --- FORECASTS: 12 HRS, VALID AT: 021800Z --- 20.5S 73.2E MAX SUSTAINED WINDS - 065 KT, GUSTS 080 KT WIND RADII VALID OVER OPEN WATER ONLY RADIUS OF 050 KT WINDS - 035 NM NORTHEAST QUADRANT 040 NM SOUTHEAST QUADRANT 040 NM SOUTHWEST QUADRANT 035 NM NORTHWEST QUADRANT RADIUS OF 034 KT WINDS - 085 NM NORTHEAST QUADRANT 090 NM SOUTHEAST QUADRANT 090 NM SOUTHWEST QUADRANT 085 NM NORTHWEST QUADRANT VECTOR TO 24 HR POSIT: 240 DEG/ 04 KTS --- 24 HRS, VALID AT: 030600Z --- 20.9S 72.5E MAX SUSTAINED WINDS - 060 KT, GUSTS 075 KT WIND RADII VALID OVER OPEN WATER ONLY RADIUS OF 050 KT WINDS - 035 NM NORTHEAST QUADRANT 040 NM SOUTHEAST QUADRANT 040 NM SOUTHWEST QUADRANT 035 NM NORTHWEST QUADRANT RADIUS OF 034 KT WINDS - 080 NM NORTHEAST QUADRANT 085 NM SOUTHEAST QUADRANT 085 NM SOUTHWEST QUADRANT 080 NM NORTHWEST QUADRANT VECTOR TO 36 HR POSIT: 275 DEG/ 04 KTS --- 36 HRS, VALID AT: 031800Z --- 20.8S 71.7E MAX SUSTAINED WINDS - 055 KT, GUSTS 070 KT WIND RADII VALID OVER OPEN WATER ONLY RADIUS OF 050 KT WINDS - 030 NM NORTHEAST QUADRANT 035 NM SOUTHEAST QUADRANT 035 NM SOUTHWEST QUADRANT 030 NM NORTHWEST QUADRANT RADIUS OF 034 KT WINDS - 075 NM NORTHEAST QUADRANT 080 NM SOUTHEAST QUADRANT 080 NM SOUTHWEST QUADRANT 075 NM NORTHWEST QUADRANT VECTOR TO 48 HR POSIT: 285 DEG/ 05 KTS --- EXTENDED OUTLOOK: 48 HRS, VALID AT: 040600Z --- 20.5S 70.6E MAX SUSTAINED WINDS - 050 KT, GUSTS 065 KT WIND RADII VALID OVER OPEN WATER ONLY RADIUS OF 034 KT WINDS - 075 NM NORTHEAST QUADRANT 080 NM SOUTHEAST QUADRANT 080 NM SOUTHWEST QUADRANT 075 NM NORTHWEST QUADRANT VECTOR TO 72 HR POSIT: 275 DEG/ 03 KTS --- 72 HRS, VALID AT: 050600Z --- 20.4S 69.3E MAX SUSTAINED WINDS - 040 KT, GUSTS 050 KT WIND RADII VALID OVER OPEN WATER ONLY RADIUS OF 034 KT WINDS - 060 NM NORTHEAST QUADRANT 075 NM SOUTHEAST QUADRANT 075 NM SOUTHWEST QUADRANT 060 NM NORTHWEST QUADRANT VECTOR TO 96 HR POSIT: 280 DEG/ 05 KTS --- LONG RANGE OUTLOOK: --- 96 HRS, VALID AT: 060600Z --- 20.1S 67.2E MAX SUSTAINED WINDS - 030 KT, GUSTS 040 KT WIND RADII VALID OVER OPEN WATER ONLY DISSIPATED AS A SIGNIFICANT TROPICAL CYCLONE OVER WATER --- REMARKS: 020900Z POSITION NEAR 19.9S 73.7E. TROPICAL CYCLONE (TC) 04S (BENILDE), LOCATED APPROXIMATELY 750 NM SOUTH OF DIEGO GARCIA, HAS TRACKED SOUTHWARD AT 05 KNOTS OVER THE PAST SIX HOURS. ANIMATED MULTISPECTRAL SATELLITE IMAGERY SHOWS A CLEAR WEAKENING TREND, WITH CONVECTION OVER THE NORTHWEST QUADRANT WANING AND THE EYE FILLING. INFRARED IMAGERY ANALYSIS INDICATES THE RAGGED EYE HAS SHRUNK TO 5 NM AND COOLED SIGNIFICANTLY OVER THE PAST 12 HOURS. LIKEWISE, A TIME SERIES OF AMSUB RADIAL CROSS SECTIONS VERIFY THE MID-LEVEL WARM ANOMALY HAS STEADILY COOLED AND SANK DURING THE PAST 48 HOURS. DVORAK INTENSITY ASSESSMENTS HAVE FALLEN TO 75 KNOTS FROM PGTW AND 65 KNOTS FROM FMEE. INFRARED ANIMATION INDICATES THE SYSTEM HAS DEVELOPED SOME VERTICAL TILT AS THE CONVECTIVE CLOUD SHIELD HAS STRETCHED TO THE SOUTHEAST IN RESPONSE TO ENCROACHING UPPER LEVEL WESTERLIES. SO FAR, THE BENEFITS OF ENHANCED POLEWARD OUTFLOW HAS BALANCED THE INCREASING VERTICAL WIND SHEAR ASSOCIATED WITH THE UPPER LEVEL WESTERLIES, BUT THE WESTERLIES HAVE ALTERED STORM MOTION TOWARDS THE SOUTH, WHICH WILL BRING THE SYSTEM INTO COOLER WATERS AND HIGHER VERTICAL WIND SHEAR. CURRENTLY, VERTICAL WIND SHEAR IS ESTIMATED AT 20 KNOTS AND SEA SURFACE TEMPERATURES ARE A MINIMALLY SUPPORTIVE 26 DEGREES. ONE FACTOR SUSTAINING SYSTEM INTENSITY IS THE PRESENCE OF DEEP MOISTURE, EVEN IN AREAS LACKING CONVECTION. TOTAL PRECIPITABLE WATER LOOPS DEPICT TC 04S TAPPING INTO THE DEEP MOISTURE SOURCE ASSOCIATED WITH THE SOUTHERN HEMISPHERE MONSOON TROUGH, WHILE ON THE POLEWARD SIDE IT REMAINS RELATIVELY WELL ENSCONCED FROM THE DRIER AIR ASSOCIATED WITH THE MID-LATITUDE FLOW. ANIMATED WATER VAPOR IMAGERY SHOWS INCREASING IMPINGEMENT ON OUTFLOW OVER THE NORTHEAST QUADRANT, BUT OUTFLOW OVER THE EASTERN SEMICIRCLE LOOKS GOOD AND A WELL-DEVELOPED POLEWARD CHANNEL PERSISTS. THE SYSTEM IS TRACKING POLEWARD ALONG THE WESTERN PERIPHERY OF THE DEEP SUBTROPICAL RIDGE (STR) AND IS FORECAST TO CONTINUE TRACKING SOUTHWARD TO SOUTH-SOUTHWESTWARD THROUGH TAU 12, THEN BEND WESTWARD AS A LOW- TO MID-LEVEL STEERING RIDGE ASSOCIATED WITH MID-LATITUDE FLOW BECOMES THE DOMINANT STEERING MECHANISM. MODEL GUIDANCE CONTINUES TO COME INTO BETTER AGREEMENT WITH EACH SUCCESSIVE MODEL RUN. THUS FAR, GFS AND ECMWF HAVE BEEN PERFORMING THE BEST OF THE CONSENSUS AIDS. THE FORECAST TRACK IS CLOSE TO, BUT SLOWER THAN CONSENSUS. THE PROJECTED TRACK WILL BRING TC 04S INTO A REGION OF INCREASING VERTICAL WIND SHEAR AND UPPER LEVEL SUBSIDENCE, AND THOSE IMPEDIMENTS COMBINED WITH THE COOLING SEA WATERS WILL RESULT IN STEADY DISSIPATION OVER WATER. MAXIMUM SIGNIFICANT WAVE HEIGHT AT 020600Z IS 20 FEET. NEXT WARNINGS AT 022100Z AND 030900Z.// ========================================================================= WTXS32 PGTW 20120102 21:00z MSGID/GENADMIN/NAVMARFCSTCEN PEARL HARBOR HI/JTWC// SUBJ/TROPICAL CYCLONE 04S (BENILDE) WARNING NR 012// RMKS/ 1. TROPICAL CYCLONE 04S (BENILDE) WARNING NR 012 01 ACTIVE TROPICAL CYCLONE IN SOUTHIO MAX SUSTAINED WINDS BASED ON ONE-MINUTE AVERAGE WIND RADII VALID OVER OPEN WATER ONLY --- WARNING POSITION: 021800Z --- NEAR 20.9S 73.3E MOVEMENT PAST SIX HOURS - 210 DEGREES AT 06 KTS POSITION ACCURATE TO WITHIN 060 NM POSITION BASED ON CENTER LOCATED BY SATELLITE PRESENT WIND DISTRIBUTION: MAX SUSTAINED WINDS - 070 KT, GUSTS 085 KT WIND RADII VALID OVER OPEN WATER ONLY RADIUS OF 064 KT WINDS - 035 NM NORTHEAST QUADRANT 035 NM SOUTHEAST QUADRANT 035 NM SOUTHWEST QUADRANT 035 NM NORTHWEST QUADRANT RADIUS OF 050 KT WINDS - 050 NM NORTHEAST QUADRANT 050 NM SOUTHEAST QUADRANT 050 NM SOUTHWEST QUADRANT 050 NM NORTHWEST QUADRANT RADIUS OF 034 KT WINDS - 085 NM NORTHEAST QUADRANT 105 NM SOUTHEAST QUADRANT 105 NM SOUTHWEST QUADRANT 085 NM NORTHWEST QUADRANT REPEAT POSIT: 20.9S 73.3E --- FORECASTS: 12 HRS, VALID AT: 030600Z --- 21.5S 72.5E MAX SUSTAINED WINDS - 055 KT, GUSTS 070 KT WIND RADII VALID OVER OPEN WATER ONLY RADIUS OF 050 KT WINDS - 040 NM NORTHEAST QUADRANT 040 NM SOUTHEAST QUADRANT 040 NM SOUTHWEST QUADRANT 040 NM NORTHWEST QUADRANT RADIUS OF 034 KT WINDS - 075 NM NORTHEAST QUADRANT 090 NM SOUTHEAST QUADRANT 090 NM SOUTHWEST QUADRANT 075 NM NORTHWEST QUADRANT VECTOR TO 24 HR POSIT: 275 DEG/ 04 KTS --- 24 HRS, VALID AT: 031800Z --- 21.4S 71.6E MAX SUSTAINED WINDS - 045 KT, GUSTS 055 KT WIND RADII VALID OVER OPEN WATER ONLY RADIUS OF 034 KT WINDS - 060 NM NORTHEAST QUADRANT 075 NM SOUTHEAST QUADRANT 075 NM SOUTHWEST QUADRANT 060 NM NORTHWEST QUADRANT VECTOR TO 36 HR POSIT: 295 DEG/ 05 KTS --- 36 HRS, VALID AT: 040600Z --- 21.0S 70.6E MAX SUSTAINED WINDS - 040 KT, GUSTS 050 KT WIND RADII VALID OVER OPEN WATER ONLY RADIUS OF 034 KT WINDS - 045 NM NORTHEAST QUADRANT 055 NM SOUTHEAST QUADRANT 055 NM SOUTHWEST QUADRANT 045 NM NORTHWEST QUADRANT VECTOR TO 48 HR POSIT: 285 DEG/ 04 KTS --- EXTENDED OUTLOOK: 48 HRS, VALID AT: 041800Z --- 20.8S 69.8E MAX SUSTAINED WINDS - 035 KT, GUSTS 045 KT WIND RADII VALID OVER OPEN WATER ONLY DISSIPATING AS A SIGNIFICANT TROPICAL CYCLONE OVER WATER VECTOR TO 72 HR POSIT: 270 DEG/ 04 KTS --- 72 HRS, VALID AT: 051800Z --- 20.8S 68.1E MAX SUSTAINED WINDS - 030 KT, GUSTS 040 KT WIND RADII VALID OVER OPEN WATER ONLY DISSIPATED AS A SIGNIFICANT TROPICAL CYCLONE OVER WATER --- REMARKS: 022100Z POSITION NEAR 21.1S 73.1E. TROPICAL CYCLONE (TC) 04S (BENILDE), LOCATED APPROXIMATELY 810 NM SOUTH OF DIEGO GARCIA, HAS TRACKED SOUTH-SOUTHWESTWARD AT 06 KNOTS OVER THE PAST SIX HOURS. ANIMATED INFRARED SATELLITE IMAGERY REVEALS THAT TC 04S HAS BEGUN TRACKING MORE SOUTHWESTWARD AS FORECAST AND CONTINUES ITS WEAKENING TREND, WITH SIGNIFICANT WESTERLY VERTICAL WIND SHEAR (VWS) IMPINGING ON THE NORTHERN QUADRANT LEADING THE LOW LEVEL CIRCULATION CENTER (LLCC) TO BECOME NEARLY EXPOSED. VWS VALUES ARE BETWEEN 20-30 KTS. AN ANIMATED TOTAL PRECIPITABLE WATER PRODUCT REVEALS THAT TC 04S CONTINUES TO HAVE AN ABUNDANT SUPPLY OF ATMOSPHERIC MOISTURE FROM THE SOUTHERN HEMISPHERE MONSOON TROUGH. ADDITIONALLY, IT IS NOW BEING SUPPLIED MOISTURE BY DISTURBANCE 98S WHICH IS ALMOST DIRECTLY NORTH OF AND APPROACHING TC 04S. ANIMATED WATER VAPOR IMAGERY SHOWS THAT TC 04S STILL HAS A DECENT POLEWARD OUTFLOW CHANNEL DUE TO STRONG WESTERLIES TO THE SOUTH OF THE SYSTEM. HOWEVER, THE EFFECTS OF SHEAR AND COOLER SEA SURFACE TEMPERATURES (SST) AS IT CONTINUES MOVING SOUTHWARD ARE TOO MUCH TO OVERCOME. SST VALUES ARE NOW ESTIMATED AT 25 DEGREES CELSIUS WHICH IS NOT SUPPORTIVE OF FURTHER DEVELOPMENT. THE SYSTEM IS FORECAST TO TRACK GENERALLY WESTWARD ALONG A LOW- TO MID- LEVEL STEERING RIDGE THAT HAS BUILT IN TO THE SOUTH AND WILL CONTINUE TO STEADILY WEAKEN DUE TO INCREASING VWS AND DECREASING SSTS UNTIL DISSIPATING OVER WATER BY TAU 72. THE AVAILABLE NUMERICAL MODEL GUIDANCE IS IN GOOD AGREEMENT WITH THIS SCENARIO, EXCEPT FOR THE GFS MODEL WHICH TRIES TO TAKE TC 04S DUE SOUTH INTO THE RIDGE. THE FORECAST TRACK CLOSELY FOLLOWS THE PREVIOUS FORECAST AND IS SLIGHTLY NORTH OF CONSENSUS TO ACCOUNT FOR THE EFFECTS OF THE GFS SOLUTION. MAXIMUM SIGNIFICANT WAVE HEIGHT AT 021800Z IS 30 FEET. NEXT WARNINGS AT 030900Z AND 032100Z. ========================================================================= WTXS32 PGTW 20120103 09:00z MSGID/GENADMIN/NAVMARFCSTCEN PEARL HARBOR HI/JTWC// SUBJ/TROPICAL CYCLONE 04S (BENILDE) WARNING NR 013// RMKS/ 1. TROPICAL CYCLONE 04S (BENILDE) WARNING NR 013 01 ACTIVE TROPICAL CYCLONE IN SOUTHIO MAX SUSTAINED WINDS BASED ON ONE-MINUTE AVERAGE WIND RADII VALID OVER OPEN WATER ONLY --- WARNING POSITION: 030600Z --- NEAR 21.6S 73.0E MOVEMENT PAST SIX HOURS - 195 DEGREES AT 03 KTS POSITION ACCURATE TO WITHIN 060 NM POSITION BASED ON CENTER LOCATED BY SATELLITE PRESENT WIND DISTRIBUTION: MAX SUSTAINED WINDS - 055 KT, GUSTS 070 KT WIND RADII VALID OVER OPEN WATER ONLY RADIUS OF 050 KT WINDS - 030 NM NORTHEAST QUADRANT 035 NM SOUTHEAST QUADRANT 025 NM SOUTHWEST QUADRANT 020 NM NORTHWEST QUADRANT RADIUS OF 034 KT WINDS - 090 NM NORTHEAST QUADRANT 120 NM SOUTHEAST QUADRANT 095 NM SOUTHWEST QUADRANT 070 NM NORTHWEST QUADRANT REPEAT POSIT: 21.6S 73.0E --- FORECASTS: 12 HRS, VALID AT: 031800Z --- 22.0S 72.6E MAX SUSTAINED WINDS - 045 KT, GUSTS 055 KT WIND RADII VALID OVER OPEN WATER ONLY RADIUS OF 034 KT WINDS - 085 NM NORTHEAST QUADRANT 115 NM SOUTHEAST QUADRANT 090 NM SOUTHWEST QUADRANT 065 NM NORTHWEST QUADRANT VECTOR TO 24 HR POSIT: 285 DEG/ 04 KTS --- 24 HRS, VALID AT: 040600Z --- 21.8S 71.7E MAX SUSTAINED WINDS - 040 KT, GUSTS 050 KT WIND RADII VALID OVER OPEN WATER ONLY RADIUS OF 034 KT WINDS - 080 NM NORTHEAST QUADRANT 110 NM SOUTHEAST QUADRANT 085 NM SOUTHWEST QUADRANT 060 NM NORTHWEST QUADRANT VECTOR TO 36 HR POSIT: 275 DEG/ 06 KTS --- 36 HRS, VALID AT: 041800Z --- 21.7S 70.5E MAX SUSTAINED WINDS - 035 KT, GUSTS 045 KT WIND RADII VALID OVER OPEN WATER ONLY VECTOR TO 48 HR POSIT: 265 DEG/ 06 KTS --- EXTENDED OUTLOOK: 48 HRS, VALID AT: 050600Z --- 21.8S 69.3E MAX SUSTAINED WINDS - 030 KT, GUSTS 040 KT WIND RADII VALID OVER OPEN WATER ONLY DISSIPATING AS A SIGNIFICANT TROPICAL CYCLONE OVER WATER VECTOR TO 72 HR POSIT: 250 DEG/ 06 KTS --- 72 HRS, VALID AT: 060600Z --- 22.5S 66.9E MAX SUSTAINED WINDS - 025 KT, GUSTS 035 KT WIND RADII VALID OVER OPEN WATER ONLY DISSIPATED AS A SIGNIFICANT TROPICAL CYCLONE OVER WATER --- REMARKS: 030900Z POSITION NEAR 21.7S 72.9E. TROPICAL CYCLONE (TC) 04S (BENILDE), LOCATED APPROXIMATELY 840 NM SOUTH OF DIEGO GARCIA, HAD TRACKED SOUTHWARD AT 03 KNOTS DURING THE PAST SIX HOURS. ANIMATED MULTISPECTRAL SATELLITE IMAGERY SHOWS A PARTIALLY EXOPOSED LOW-LEVEL CIRCULATION CENTER (LLCC) DUE TO MODERATE (30-KNOT) WESTERLY VERTICAL WIND SHEAR (VWS). A 030335Z SSMIS 37 GHZ IMAGE DEPICTS TIGHTLY CURVED BANDING OVER THE SOUTHERN SEMICIRCLE OF THE LLCC WITH MUCH WEAKER BANDING TO THE NORTH. A COMPARISON OF THE 91 GHZ VERSION OF THE SAME IMAGE INDICATES THAT THE VORTEX ASSOCIATED WITH TC 04S IS TILITED TO THE EAST AS ALTITUDE INCREASES. A 030435Z PARTIAL ASCAT PASS INDICATES 40-45 KNOT WINDS APPROXIMATELY 70 NM EAST OF THE LLCC. THE CURRENT POSITION IS BASED ON AN EXTRAPOLATION FROM THE SSMIS IMAGE AND A FMEE CENTER FIX. THE CURRENT INTENSITY IS BASED ON THE LOW SIDE OF DVORAK ESTIMATES RANGING FROM 55-65 KNOTS FROM FMEE/KNES AND PGTW RESPECTIVELY. RECENT UPPER-LEVEL ANALYSIS DEPICTS TC BENILDE TO BE JUST EQUATORWARD OF THE SUBTROPICAL RIDGE AXIS IN AN AREA OF MODERATE WESTERLY VWS PRODUCED BY A BAROCLINIC ANTICYCLONE TO THE WEST COMBINED WITH THE STRONG WESTERLY FLOW OVER THE MID-LATITUDES. UPPER DIVERGENCE IS STRONG TO THE EAST OF THE LLCC BUT THE ENTIRE WESTERN PORTION IS DOMINATED BY CONVERGENCE. TOTAL PRECIPITABLE ANIMATION REVEALS THAT THE CYCLONIC MOSITURE FIELD THAT WAS ONCE ASSOCIATED WITH THE LLCC TO THE NORTH (98S) OF TC 04S IS NOW A CONTINUOUS BAND OF MOISTURE FEEDING INTO TC BENILDE. THIS INDICATES THAT THE SYSTEMS HAVE MERGED AND ANY POSSIBLE DIRECT CYCLONE INTERACTION HAS DISSIPATED. TC 04S IS CURRENTLY TRACKING SLOWLY SOUTHWARDS TOWARDS A FLEETING BREAK IN THE LOW- TO MID-LEVEL SUBTROPICAL RIDGING. BY TAU 12 THE BAROCLINIC LOW- TO MID-LEVEL ANTICYCLONE WILL HAVE BUILT INTO THE AREA AND INFLUENCE TC 04S TO TRACK GENERALLY WESTWARDS AS THE SYSTEM CONTINUES TO WEAKEN DUE TO CONTINUED MODERATE TO STRONG VWS AND DECREASING SEA SURFACE TEMPERATURES. NUMERICAL MODEL GUIDANCE IS IN OVERALL GOOD AGREEMENT AS TO THE WESTWARD TRACK WITH THE GFDN AND EGRR BEING TO RIGHT MOST OUTLIERS AND THE WBAR BEING THE LEFT MOST OUTLIER. THE OFFICIAL FORECAST LIES CLOSE TO THE MODEL CONSENSUS DUE TO THE GENERAL GOOD AGREEMENT OF THE OBJECTIVE AIDS. MAXIMUM SIGNIFICANT WAVE HEIGHT AT 030600Z IS 25 FEET. NEXT WARNINGS AT 032100Z AND 040900Z.// ========================================================================= WTXS32 PGTW 20120103 21:00z MSGID/GENADMIN/NAVMARFCSTCEN PEARL HARBOR HI/JTWC// SUBJ/TROPICAL CYCLONE 04S (BENILDE) WARNING NR 014// RMKS/ 1. TROPICAL CYCLONE 04S (BENILDE) WARNING NR 014 01 ACTIVE TROPICAL CYCLONE IN SOUTHIO MAX SUSTAINED WINDS BASED ON ONE-MINUTE AVERAGE WIND RADII VALID OVER OPEN WATER ONLY --- WARNING POSITION: 031800Z --- NEAR 21.8S 73.5E MOVEMENT PAST SIX HOURS - 030 DEGREES AT 04 KTS POSITION ACCURATE TO WITHIN 060 NM POSITION BASED ON CENTER LOCATED BY SATELLITE PRESENT WIND DISTRIBUTION: MAX SUSTAINED WINDS - 040 KT, GUSTS 050 KT WIND RADII VALID OVER OPEN WATER ONLY DISSIPATING AS A SIGNIFICANT TROPICAL CYCLONE OVER WATER RADIUS OF 034 KT WINDS - 040 NM NORTHEAST QUADRANT 055 NM SOUTHEAST QUADRANT 055 NM SOUTHWEST QUADRANT 040 NM NORTHWEST QUADRANT REPEAT POSIT: 21.8S 73.5E --- FORECASTS: 12 HRS, VALID AT: 040600Z --- 21.6S 72.9E MAX SUSTAINED WINDS - 035 KT, GUSTS 045 KT WIND RADII VALID OVER OPEN WATER ONLY DISSIPATING AS A SIGNIFICANT TROPICAL CYCLONE OVER WATER VECTOR TO 24 HR POSIT: 280 DEG/ 03 KTS --- 24 HRS, VALID AT: 041800Z --- 21.5S 72.3E MAX SUSTAINED WINDS - 030 KT, GUSTS 040 KT WIND RADII VALID OVER OPEN WATER ONLY DISSIPATED AS A SIGNIFICANT TROPICAL CYCLONE OVER WATER --- REMARKS: 032100Z POSITION NEAR 21.8S 73.4E. TROPICAL CYCLONE (TC) 04S (BENILDE), LOCATED APPROXIMATELY 865 NM SOUTH OF DIEGO GARCIA HAS TRACKED NORTH-NORTHEASTWARD AT 04 KNOTS DURING THE PAST SIX HOURS. ANIMATED INFRARED SATELLITE IMAGERY REVEALS A FULLY EXPOSED LOW-LEVEL CIRCULATION CENTER (LLCC) UNDER THE EFFECTS OF STRONG (30-40 KNOT) WESTERLY VERTICAL WIND SHEAR (VWS). THE LLCC HAS BECOME QUASI-STATIONARY AS A MID- TO LOW- LEVEL RIDGE IS BUILDING TO THE SOUTH. A 031701Z METOP-A 89 GHZ IMAGE SHOWS THAT TIGHTLY CURVED BANDING REMAINS IN PLACE IN THE SOUTHERN QUADRANT WITH MUCH WEAKER BANDING TO THE NORTH. THE MOST RECENT AMSU RADIAL CROSS SECTION SHOWS THAT TC 04S HAS MAINTAINED ITS WARM CORE STRUCTURE DESPITE THE STRONG VWS. THE CURRENT INTENSITY IS BASED ON A 031658Z PARTIAL ASCAT IMAGE WHICH REVEALS THE SYSTEM STILL HAS MAXIMUM WINDS OF 40 KNOTS IN THE SOUTHERN QUADRANT. UPPER LEVEL ANALYSIS INDICATES TC 04S IS NOW SOUTH OF THE RIDGE AXIS IN A COL REGION. A STRONG BAROCLINIC ANTICYCLONE TO THE WEST IS AMPLIFYING THE MIDLATITUDE WESTERLIES PRODUCING THE VWS NOTED ABOVE AND RESTRICTING THE OUTFLOW TO THE EASTERN SIDE OF THE SYSTEM. AFTER A BRIEF BURST OF CONVECTIVE ENERGY DUE TO THE ABSORPTION OF A PREVIOUS DISTURBANCE TO THE NORTH (98S), THE INTENSITY TREND HAS RESUMED WEAKENING UNDER THE EFFECTS OF THE VWS AND IS EXPECTED TO DISSIPATE BY TAU 24. AS THE MID- TO LOW- LEVEL ANTICYCLONE CONTINUES TO BUILD, THE SYSTEM SHOULD BE STEERED GENERALLY WESTWARD PRIOR TO DISSIPATING OVER WATER. THE NUMERICAL MODEL GUIDANCE IS SPLIT ON THE TRACK FORECAST WITH THE GFS AND ECMWF MODELS TAKING TC 04S SOUTH FOLLOWING A WEAKNESS IN THE RIDGE WHILE THE REST OF THE GUIDANCE SHOWS A SLOW WESTWARD MOTION, WHICH IS MOST CONSISTENT WITH THE RECENT TRACK. THE GUIDANCE IS IN VERY GOOD AGREEMENT ON THE DISSIPATION OF TC 04S BY TAU 24. MAXIMUM SIGNIFICANT WAVE HEIGHT AT 031800Z IS 22 FEET. NEXT WARNING AT 040900Z. ========================================================================= WTXS32 PGTW 20120104 09:00z MSGID/GENADMIN/NAVMARFCSTCEN PEARL HARBOR HI/JTWC// SUBJ/TROPICAL CYCLONE 04S (BENILDE) WARNING NR 015// RMKS/ 1. TROPICAL CYCLONE 04S (BENILDE) WARNING NR 015 01 ACTIVE TROPICAL CYCLONE IN SOUTHIO MAX SUSTAINED WINDS BASED ON ONE-MINUTE AVERAGE WIND RADII VALID OVER OPEN WATER ONLY --- WARNING POSITION: 040600Z --- NEAR 21.9S 74.7E MOVEMENT PAST SIX HOURS - 115 DEGREES AT 10 KTS POSITION ACCURATE TO WITHIN 060 NM POSITION BASED ON CENTER LOCATED BY SATELLITE PRESENT WIND DISTRIBUTION: MAX SUSTAINED WINDS - 035 KT, GUSTS 045 KT WIND RADII VALID OVER OPEN WATER ONLY DISSIPATING AS A SIGNIFICANT TROPICAL CYCLONE OVER WATER REPEAT POSIT: 21.9S 74.7E --- FORECASTS: 12 HRS, VALID AT: 041800Z --- 22.5S 75.7E MAX SUSTAINED WINDS - 030 KT, GUSTS 040 KT WIND RADII VALID OVER OPEN WATER ONLY DISSIPATED AS A SIGNIFICANT TROPICAL CYCLONE OVER WATER --- REMARKS: 040900Z POSITION NEAR 22.1S 75.0E. TROPICAL CYCLONE (TC) 04S (BENILDE), LOCATED APPROXIMATELY 870 NM SOUTH OF DIEGO GARCIA HAD TRACKED EAST-SOUTHEASTWARD AT 10 KNOTS DURING THE PAST SIX HOURS. ANIMATED MULTISPECTRAL SATELLITE IMAGERY REVEALS A FULLY-EXPOSED LOW-LEVEL CIRCULATION CENTER (LLCC) UNDER THE EFFECTS OF STRONG (40-KNOT) WESTERLY VERTICAL WIND SHEAR (VWS). THE LLCC HAS CONTINUED TO WEAKEN AND ELONGATE OVER THE PAST 12 HOURS AND THE CONVECTION IS CURRENTLY SHEARED APPROXIMATELY 205 NM TO THE SOUTH-SOUTHEAST. A 040414Z PARTIAL ASCAT PASS INDICATES 30-KNOT WINDS OVER THE SOUTHEASTERN QUADRANT OF THE LLCC. THE CURRENT POSITION IS BASED ON AGREEABLE PGTW AND KNES CENTER FIXES WITH FAIR CONFIDENCE DUE TO THE WEAKENING AND ILL-DEFINED LLCC. THE CURRENT INTENSITY IS BASED ON A DVORAK ESTIMATE OF 35 KNOTS FROM PGTW AND THE ASCAT PARTIAL PASS. RECENT UPPER-LEVEL ANALYSIS PUTS THE LLCC APPROXIMATELY 5 DEGREES POLEWARD OF THE SUBTROPICAL RIDGE AXIS WITH AN UPPER-LEVEL TROUGH APPROXIAMTELY 6 DEGREES TO THE WEST AND CLOSING. ANIMATED WATER VAPOR IMAGERY CLEARLY SHOWS THE NEGATIVE EFFECTS OF UPPER-LEVEL CONVERGENCE AND STRONG VWS OVER TC 04S. THE SYSTEM IS CURRENTLY SURROUNDED BY UNFAVORABLE 25 DEGREE SEA SURFACE TEMPERATURES. TC 04S WILL SUCCUMB TO THE STRONG VWS AND UNFAVORABLE SEA SURFACE TEMPERATURES DURING THE NEXT 12 HOURS AND DISSIPATE OVER WATER. THIS IS THE FINAL WARNING ON THIS SYSTEM BY THE JOINT TYPHOON WARNING CENTER (NAVMARFCSTCEN). THE SYSTEM WILL BE CLOSELY MONI- TORED FOR SIGNS OF REGENERATION. MAXIMUM SIGNIFICANT WAVE HEIGHT AT 040600Z IS 20 FEET.//
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Document: tropical_cyclone_benilde.htm | Updated: 8 January 2012 |