Tropical Cyclones [Index]

Tropical Cyclone PETA Southern Hemisphere Summary

WTXS21 PGTW 20130121 22:00z
MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI//
SUBJ/TROPICAL CYCLONE FORMATION ALERT//
RMKS/
1. FORMATION OF A SIGNIFICANT TROPICAL CYCLONE IS POSSIBLE WITHIN
120 NM EITHER SIDE OF A LINE FROM 19.2S 120.7E TO 20.3S 116.2E
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 25 TO 30 KNOTS. METSAT IMAGERY,
SYNOPTIC DATA AND RADAR DATA AT 212130Z INDICATE THAT A CIRCULATION
CENTER IS LOCATED NEAR 19.2S 120.7E. THE SYSTEM IS MOVING WEST-
SOUTHWESTWARD AT 08 KNOTS.
2. REMARKS: THE AREA OF CONVECTION PREVIOUSLY LOCATED NEAR 18.7S
121.1E IS NOW LOCATED NEAR 19.2S 120.7E, APPROXIMATELY 415 NM EAST-
NORTHEAST OF LEARMONTH, AUSTRALIA. ANIMATED INFRARED SATELLITE
IMAGERY DEPICTS A CONSOLIDATING LOW-LEVEL CIRCULATION CENTER (LLCC)
WITH IMPROVED DEEP CONVECTIVE BANDING. A 211746Z AMSU IMAGE SHOWS
THAT THE LLCC IS BECOMING MORE ORGANIZED WITH DEEP CONVECTIVE
BANDING WRAPPING INTO A SLIGHTLY ELONGATED LLCC. THE BROOME RADAR
SHOWS A DEFINED LLCC WITH A RING OF FRAGMENTED CONVECTION NEAR THE
CENTER AND STRONG CONVECTION PERSISTING OVER THE EAST (CONVERGENT
FLOW) QUADRANT. SURFACE OBSERVATIONS FROM MANDORA SHOW EASTERLY
SUSTAINED WINDS OF 10 KNOTS GUSTING TO 15 TO 20 KNOTS AND SLP 1003
MB. UPPER-LEVEL ANALYSIS INDICATES THAT THE LLCC IS LOCATED UNDER
THE SUBTROPICAL RIDGE AXIS WITH WEAK VERTICAL WIND SHEAR (10 TO 15
KNOTS) AND GOOD POLEWARD OUTFLOW, ENHANCED BY MODEARTE NORTHWESTERLY
FLOW OVER WESTERN AUSTRALIA. MAXIMUM SUSTAINED SURFACE WINDS ARE
ESTIMATED AT 25 TO 30 KNOTS. MINIMUM SEA LEVEL PRESSURE IS ESTIMATED
TO BE NEAR 1002 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
222200Z.//
=========================================================================
WTXS31 PGTW 20130122 21:00z
MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI//
SUBJ/TROPICAL CYCLONE 12S (TWELVE) WARNING NR 001//
REF/A/MSG/JOINT TYPHOON WRNCEN PEARL HARBOR HI/212151ZJAN2013//
AMPN/REF A IS A TROPICAL CYCLONE FORMATION ALERT.//
RMKS/
1. TROPICAL CYCLONE 12S (TWELVE) 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:
   221800Z --- NEAR 19.7S 117.8E
     MOVEMENT PAST SIX HOURS - 275 DEGREES AT 09 KTS
     POSITION ACCURATE TO WITHIN 030 NM
     POSITION BASED ON CENTER LOCATED BY A COMBINATION OF
     SATELLITE, RADAR AND SYNOPTIC DATA
   PRESENT WIND DISTRIBUTION:
   MAX SUSTAINED WINDS - 030 KT, GUSTS 040 KT
   WIND RADII VALID OVER OPEN WATER ONLY
   REPEAT POSIT: 19.7S 117.8E
    ---
   FORECASTS:
   12 HRS, VALID AT:
   230600Z --- 20.0S 117.1E
   MAX SUSTAINED WINDS - 035 KT, GUSTS 045 KT
   WIND RADII VALID OVER OPEN WATER ONLY
   VECTOR TO 24 HR POSIT: 235 DEG/ 05 KTS
    ---
   24 HRS, VALID AT:
   231800Z --- 20.5S 116.3E
   MAX SUSTAINED WINDS - 040 KT, GUSTS 050 KT
   WIND RADII VALID OVER OPEN WATER ONLY
   RADIUS OF 034 KT WINDS - 045 NM NORTHEAST QUADRANT
                            045 NM SOUTHEAST QUADRANT
                            045 NM SOUTHWEST QUADRANT
                            045 NM NORTHWEST QUADRANT
   VECTOR TO 36 HR POSIT: 230 DEG/ 04 KTS
    ---
   36 HRS, VALID AT:
   240600Z --- 21.0S 115.7E
   MAX SUSTAINED WINDS - 035 KT, GUSTS 045 KT
   WIND RADII VALID OVER OPEN WATER ONLY
   VECTOR TO 48 HR POSIT: 245 DEG/ 05 KTS
    ---
   EXTENDED OUTLOOK:
   48 HRS, VALID AT:
   241800Z --- 21.4S 114.8E
   MAX SUSTAINED WINDS - 035 KT, GUSTS 045 KT
   WIND RADII VALID OVER OPEN WATER ONLY
   VECTOR TO 72 HR POSIT: 265 DEG/ 06 KTS
    ---
   72 HRS, VALID AT:
   251800Z --- 21.6S 112.1E
   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 96 HR POSIT: 280 DEG/ 07 KTS
    ---
   LONG RANGE OUTLOOK:
    ---
   96 HRS, VALID AT:
   261800Z --- 21.1S 109.0E
   MAX SUSTAINED WINDS - 030 KT, GUSTS 040 KT
   WIND RADII VALID OVER OPEN WATER ONLY
   DISSIPATED AS A SIGNIFICANT TROPICAL CYCLONE OVER WATER
   VECTOR TO 120 HR POSIT: 290 DEG/ 08 KTS
    ---
   120 HRS, VALID AT:
   271800Z --- 19.9S 105.9E
   MAX SUSTAINED WINDS - 025 KT, GUSTS 035 KT
   WIND RADII VALID OVER OPEN WATER ONLY
   DISSIPATED AS A SIGNIFICANT TROPICAL CYCLONE OVER WATER
    ---
REMARKS:
222100Z POSITION NEAR 19.8S 117.6E.
TROPICAL CYCLONE (TC) 12S, LOCATED APPROXIMATELY 260 NM NORTHEAST OF
LEARMONTH, AUSTRALIA, HAS TRACKED WESTWARD AT 09 KNOTS OVER THE PAST
SIX HOURS. ANIMATED INFRARED SATELLITE IMAGERY DEPICTS A
CONSOLIDATING LOW-LEVEL CIRCULATION CENTER (LLCC) WITH INCREASED
DEEP CONVECTION OVER THE LLCC. A 221736Z AMSU IMAGE DEPICTS IMPROVED
DEEP CONVECTIVE BANDING OVER THE SOUTHERN SEMI-CIRCLE WRAPPING INTO
THE SOUTHWEST QUADRANT OF THE LLCC. THE PORT HEDLAND RADAR SHOWS A
DEFINED LLCC WITH CONVECTIVE BANDING WRAPPING INTO THE LLCC AND
STRONG CONVECTION PERSISTING OVER THE SOUTHEAST (CONVERGENT FLOW)
QUADRANT. SURFACE OBSERVATIONS FROM PORT HEDLAND AND BEDOUT ISLAND
INDICATE SUSTAINED WINDS OF 20 TO 25 KNOTS GUSTING TO 30 KNOTS AND
SLP NEAR 1000 MB. UPPER-LEVEL ANALYSIS INDICATES THAT THE LLCC IS
LOCATED UNDER THE SUBTROPICAL RIDGE AXIS WITH WEAK VERTICAL WIND
SHEAR (10 TO 15 KNOTS) AND GOOD POLEWARD OUTFLOW, ENHANCED BY
MODERATE NORTHWESTERLY FLOW OVER WESTERN AUSTRALIA. THE INITIAL
INTENSITY IS ASSESSED AT 30 KNOTS BASED ON THE AVAILABLE
OBSERVATIONS AND IS BOLSTERED BY SCATTEROMETER DATA AND DVORAK
ESTIMATES OF 30 KNOTS. THERE IS HIGH CONFIDENCE IN THE INITIAL
POSITION BASED ON THE RADAR IMAGERY. TC 12S IS FORECAST TO TURN
SOUTHWESTWARD AS THE LOW-LEVEL STEERING RIDGE WEAKENS IN RESPONSE TO
AN APPROACHING MIDLATITUDE SHORTWAVE TROUGH AFTER TAU 12. AFTER
TROUGH PASSAGE, THE LOW-LEVEL STEERING RIDGE IS FORECAST TO BUILD
WEST OF AUSTRALIA PROVING A WESTWARD TO WEST-NORTHWESTWARD STEERING
INFLUENCE. TC 12S IS FORECAST TO INTENSIFY TO A PEAK OF 35 TO 40
KNOTS BY TAU 24 BUT SHOULD WEAKEN DUE TO LAND INTERACTION,
INITIALLY, THEN WEAKEN FURTHER AS IT TRACKS OVER COOLER SST (24 TO
26C) AFTER TAU 72. DYNAMIC MODEL GUIDANCE IS IN GOOD AGREEMENT,
THEREFORE, THERE IS HIGH CONFIDENCE IN THE JTWC FORECAST TRACK. THIS
WARNING SUPERSEDES AND CANCELS REF A, JOINT TYPHOON WRNCEN PEARL
HARBOR HI 212151Z JAN 13 TROPICAL CYCLONE FORMATION ALERT (WTXS21
PGTW 212200). MAXIMUM SIGNIFICANT WAVE HEIGHT AT 221800Z IS 10 FEET.
NEXT WARNINGS AT 230300Z, 230900Z, 231500Z AND 232100Z.//
=========================================================================
WTXS31 PGTW 20130123 03:00z
MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI//
SUBJ/TROPICAL CYCLONE 12S (TWELVE) WARNING NR 002//
RMKS/
1. TROPICAL CYCLONE 12S (TWELVE) 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:
   230000Z --- NEAR 20.2S 117.7E
     MOVEMENT PAST SIX HOURS - 225 DEGREES AT 04 KTS
     POSITION ACCURATE TO WITHIN 030 NM
     POSITION BASED ON CENTER LOCATED BY A COMBINATION OF
     SATELLITE, RADAR AND SYNOPTIC DATA
   PRESENT WIND DISTRIBUTION:
   MAX SUSTAINED WINDS - 035 KT, GUSTS 045 KT
   WIND RADII VALID OVER OPEN WATER ONLY
   REPEAT POSIT: 20.2S 117.7E
    ---
   FORECASTS:
   12 HRS, VALID AT:
   231200Z --- 20.5S 116.8E
   MAX SUSTAINED WINDS - 040 KT, GUSTS 050 KT
   WIND RADII VALID OVER OPEN WATER ONLY
   RADIUS OF 034 KT WINDS - 045 NM NORTHEAST QUADRANT
                            045 NM SOUTHEAST QUADRANT
                            045 NM SOUTHWEST QUADRANT
                            045 NM NORTHWEST QUADRANT
   VECTOR TO 24 HR POSIT: 235 DEG/ 04 KTS
    ---
   24 HRS, VALID AT:
   240000Z --- 21.0S 116.0E
   MAX SUSTAINED WINDS - 040 KT, GUSTS 050 KT
   WIND RADII VALID OVER OPEN WATER ONLY
   RADIUS OF 034 KT WINDS - 045 NM NORTHEAST QUADRANT
                            045 NM SOUTHEAST QUADRANT
                            045 NM SOUTHWEST QUADRANT
                            045 NM NORTHWEST QUADRANT
   VECTOR TO 36 HR POSIT: 240 DEG/ 04 KTS
    ---
   36 HRS, VALID AT:
   241200Z --- 21.4S 115.3E
   MAX SUSTAINED WINDS - 035 KT, GUSTS 045 KT
   WIND RADII VALID OVER OPEN WATER ONLY
   VECTOR TO 48 HR POSIT: 255 DEG/ 05 KTS
    ---
   EXTENDED OUTLOOK:
   48 HRS, VALID AT:
   250000Z --- 21.7S 114.2E
   MAX SUSTAINED WINDS - 035 KT, GUSTS 045 KT
   WIND RADII VALID OVER OPEN WATER ONLY
   VECTOR TO 72 HR POSIT: 270 DEG/ 07 KTS
    ---
   72 HRS, VALID AT:
   260000Z --- 21.7S 111.4E
   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 96 HR POSIT: 285 DEG/ 07 KTS
    ---
   LONG RANGE OUTLOOK:
    ---
   96 HRS, VALID AT:
   270000Z --- 21.0S 108.3E
   MAX SUSTAINED WINDS - 030 KT, GUSTS 040 KT
   WIND RADII VALID OVER OPEN WATER ONLY
   DISSIPATED AS A SIGNIFICANT TROPICAL CYCLONE OVER WATER
   VECTOR TO 120 HR POSIT: 290 DEG/ 08 KTS
    ---
   120 HRS, VALID AT:
   280000Z --- 19.9S 105.2E
   MAX SUSTAINED WINDS - 025 KT, GUSTS 035 KT
   WIND RADII VALID OVER OPEN WATER ONLY
   DISSIPATED AS A SIGNIFICANT TROPICAL CYCLONE OVER WATER
    ---
REMARKS:
230300Z POSITION NEAR 20.3S 117.5E.
TROPICAL CYCLONE (TC) 12S, LOCATED APPROXIMATELY 235 NM EAST-
NORTHEAST OF LEARMONTH, AUSTRALIA, HAS TRACKED SOUTHWESTWARD AT 04
KNOTS OVER THE PAST SIX HOURS. ANIMATED INFRARED SATELLITE IMAGERY
DEPICTS A CONSOLIDATING LOW-LEVEL CIRCULATION CENTER (LLCC) WITH A
CENTRAL DENSE OVERCAST FEATURE NOW OBSCURING THE LLCC. A 222336Z
SSMIS IMAGE DEPICTS IMPROVED DEEP CONVECTIVE BANDING OVER THE
SOUTHERN SEMI-CIRCLE WRAPPING TIGHTLY INTO THE NORTHWEST QUADRANT OF
THE LLCC. ADDITIONALLY, THE PORT HEDLAND RADAR SHOWS A WELL-DEFINED
CENTER WITH TIGHTLY-CURVED CONVECTIVE BANDING. OVER THE PAST SIX
HOURS, TC 12S HAS TRACKED ERRATICALLY BUT HAS RECENTLY RESUMED A
WESTWARD TRACK PARALLEL TO THE COASTLINE. SURFACE OBSERVATIONS FROM
LEGENDRE ISLAND, LOCATED 50 NM WEST OF THE CENTER, INDICATE
SUSTAINED WINDS OF 25 KNOTS GUSTING UP TO 40 KNOTS. UPPER-LEVEL
ANALYSIS INDICATES THAT THE LLCC IS LOCATED UNDER THE SUBTROPICAL
RIDGE AXIS WITH WEAK VERTICAL WIND SHEAR (10 TO 15 KNOTS) AND GOOD
POLEWARD OUTFLOW, ENHANCED BY MODERATE NORTHWESTERLY FLOW OVER
WESTERN AUSTRALIA. THE INITIAL INTENSITY IS ASSESSED AT 35 KNOTS
BASED ON A DVORAK INTENSITY ESTIMATE OF 35 KNOTS FROM PGTW. THERE IS
HIGH CONFIDENCE IN THE INITIAL POSITION BASED ON THE RADAR IMAGERY.
TC 12S IS FORECAST TO TURN SOUTHWESTWARD AS THE LOW-LEVEL STEERING
RIDGE WEAKENS IN RESPONSE TO AN APPROACHING MIDLATITUDE SHORTWAVE
TROUGH AFTER TAU 12. AFTER TROUGH PASSAGE, THE LOW-LEVEL STEERING
RIDGE IS FORECAST TO BUILD WEST OF AUSTRALIA PROVIDING A WESTWARD TO
WEST-NORTHWESTWARD STEERING INFLUENCE. TC 12S IS FORECAST TO
INTENSIFY TO A PEAK OF 40 KNOTS BY TAU 12 BUT SHOULD WEAKEN BY TAU
48 DUE TO LAND INTERACTION, INITIALLY, THEN WEAKEN FURTHER AS IT
TRACKS OVER COOLER SST (24 TO 26C) AFTER TAU 72. DYNAMIC MODEL
GUIDANCE IS IN GOOD AGREEMENT, THEREFORE, THERE IS HIGH CONFIDENCE
IN THE JTWC FORECAST TRACK. MAXIMUM SIGNIFICANT WAVE HEIGHT AT
230000Z IS 10 FEET. NEXT WARNINGS AT 230900Z, 231500Z, 232100Z AND
240300Z.//
=========================================================================
WTXS31 PGTW 20130123 09:00z
MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI//
SUBJ/TROPICAL CYCLONE 12S (PETA) WARNING NR 003//
RMKS/
1. TROPICAL CYCLONE 12S (PETA) 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:
   230600Z --- NEAR 21.1S 117.6E
     MOVEMENT PAST SIX HOURS - 185 DEGREES AT 09 KTS
     POSITION ACCURATE TO WITHIN 060 NM
     POSITION BASED ON CENTER LOCATED BY A COMBINATION OF
     SATELLITE AND RADAR
   PRESENT WIND DISTRIBUTION:
   MAX SUSTAINED WINDS - 035 KT, GUSTS 045 KT
   WIND RADII VALID OVER OPEN WATER ONLY
   REPEAT POSIT: 21.1S 117.6E
    ---
   FORECASTS:
   12 HRS, VALID AT:
   231800Z --- 21.9S 116.8E
   MAX SUSTAINED WINDS - 035 KT, GUSTS 045 KT
   WIND RADII VALID OVER OPEN WATER ONLY
   VECTOR TO 24 HR POSIT: 260 DEG/ 03 KTS
    ---
   24 HRS, VALID AT:
   240600Z --- 22.0S 116.1E
   MAX SUSTAINED WINDS - 035 KT, GUSTS 045 KT
   WIND RADII VALID OVER OPEN WATER ONLY
   VECTOR TO 36 HR POSIT: 265 DEG/ 05 KTS
    ---
   36 HRS, VALID AT:
   241800Z --- 22.1S 115.1E
   MAX SUSTAINED WINDS - 035 KT, GUSTS 045 KT
   WIND RADII VALID OVER OPEN WATER ONLY
   VECTOR TO 48 HR POSIT: 270 DEG/ 06 KTS
    ---
   EXTENDED OUTLOOK:
   48 HRS, VALID AT:
   250600Z --- 22.1S 113.7E
   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: 275 DEG/ 08 KTS
    ---
   72 HRS, VALID AT:
   260600Z --- 21.8S 110.2E
   MAX SUSTAINED WINDS - 025 KT, GUSTS 035 KT
   WIND RADII VALID OVER OPEN WATER ONLY
   DISSIPATED AS A SIGNIFICANT TROPICAL CYCLONE OVER WATER
    ---
REMARKS:
230900Z POSITION NEAR 21.3S 117.4E.
TROPICAL CYCLONE (TC) 12S (PETA), LOCATED APPROXIMATELY 210 NM EAST-
NORTHEAST OF LEARMONTH, AUSTRALIA, HAS TRACKED SOUTHWARD AT 09 KNOTS
OVER THE PAST SIX HOURS. ANIMATED MULTISPECTRAL SATELLITE IMAGERY
DEPICTS A SYMMETRIC SYSTEM WITH IMPROVED CONVECTIVE BANDING WITH A
CENTRAL DENSE OVERCAST FEATURE THAT CONTINUES TO OBSCURE THE LLCC.
THE DAMPIER AUSTRALIA RADAR SHOWS A DEFINED CENTER WITH TIGHTLY-
CURVED CONVECTIVE BANDING OVER THE SOUTHERN SEMI-CIRCLE. OVER THE
PAST SIX HOURS, TC 12S HAS TRACKED ERRATICALLY AND HAS RECENTLY MADE
A SHARP TURN TO THE SOUTH, MOVING OVERLAND. UPPER-LEVEL ANALYSIS
INDICATES THAT THE LLCC IS LOCATED UNDER THE SUBTROPICAL RIDGE AXIS
WITH WEAK VERTICAL WIND SHEAR (10 TO 15 KNOTS) AND GOOD POLEWARD
OUTFLOW, WHICH IS BEING ENHANCED BY THE NORTHWESTERLY FLOW OVER
WESTERN AUSTRALIA. THE INITIAL INTENSITY IS ASSESSED AT 35 KNOTS
BASED ON OBSERVATIONS IN THE AREA AND PERSISTENCE AS DVORAK
INTENSITY ESTIMATES WERE BEGINNING TO CLIMB PRIOR TO LANDFALL. THERE
IS HIGH CONFIDENCE IN THE INITIAL POSITION BASED ON THE RADAR
IMAGERY. TC 12S IS FORECAST TO TURN SOUTHWESTWARD AS THE LOW-LEVEL
STEERING RIDGE WEAKENS IN RESPONSE TO AN APPROACHING MIDLATITUDE
SHORTWAVE TROUGH THROUGH TAU 12. AFTER TROUGH PASSAGE, THE LOW-LEVEL
STEERING RIDGE IS FORECAST TO BUILD WEST OF AUSTRALIA PROVIDING A
WESTWARD STEERING INFLUENCE. TC 12S IS FORECAST TO MAINTAIN 35 KNOTS
THROUGH TAU 48 AS IT TRACKS ALONG THE COAST AND THEN DISSIPATE AS IT
TRACKS INTO THE INDIAN OCEAN WITH COOL SSTS (24 TO 26C) AND
INCREASING VWS. THERE IS A POSSIBILITY THAT THE SYSTEM COULD
DISSIPATE SOONER THEN TAU 72 DUE TO THE LAND INTERACTION. DYNAMIC
MODEL GUIDANCE IS IN GOOD AGREEMENT, THEREFORE, THERE IS HIGH
CONFIDENCE IN THE JTWC FORECAST TRACK. NEXT WARNINGS AT 231500Z,
232100, 240300Z AND 240900Z.//
=========================================================================
WTXS31 PGTW 20130123 15:00z
MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI//
SUBJ/TROPICAL CYCLONE 12S (PETA) WARNING NR 004//
RMKS/
1. TROPICAL CYCLONE 12S (PETA) 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:
   231200Z --- NEAR 21.6S 117.3E
     MOVEMENT PAST SIX HOURS - 210 DEGREES AT 06 KTS
     POSITION ACCURATE TO WITHIN 060 NM
     POSITION BASED ON CENTER LOCATED BY A COMBINATION OF
     SATELLITE AND RADAR
   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 LAND
   REPEAT POSIT: 21.6S 117.3E
    ---
   FORECASTS:
   12 HRS, VALID AT:
   240000Z --- 22.1S 116.7E
   MAX SUSTAINED WINDS - 030 KT, GUSTS 040 KT
   WIND RADII VALID OVER OPEN WATER ONLY
   DISSIPATED AS A SIGNIFICANT TROPICAL CYCLONE OVER LAND
    ---
REMARKS:
231500Z POSITION NEAR 21.7S 117.1E.
TROPICAL CYCLONE (TC) 12S (PETA), LOCATED APPROXIMATELY 180 NM EAST
OF LEARMONTH, AUSTRALIA, HAS TRACKED SOUTH-SOUTHWESTWARD AT 06 KNOTS
OVER THE PAST SIX HOURS. ANIMATED INFRARED SATELLITE IMAGERY
DEPICTS A WEAKENING SYSTEM AS CLOUD TOPS HAVE WARMED AND OVERALL
STRUCTURE IS BEGINNING TO BECOME IRREGULAR. OBSERVATIONS IN THE AREA
ARE SHOWING RISING PRESSURES AND WINDS HAVE WEAKENED. RADAR IMAGERY
FROM DAMPIER AUSTRALIA ALSO SHOWS A WEAKENING SIGNATURE AND THE LOW-
LEVEL CIRCULATION IS BECOMING DIFFICULT TO DEFINE AS IT HAS
CONTINUED TO TRACK OVER LAND. TC 12S IS FORECAST TO TRACK SOUTHWEST
AND STAY OVER LAND, WEAKENING BELOW WARNING THRESHOLD DUE TO THE
LAND INTERACTION. THE REMNANTS OF TC 12S WILL CONTINUE TO MOVE WEST-
SOUTHWESTWARD TRACKING CLOSE TO LEARMONTH, AUSTRALIA BUT WINDS WILL
BE WEAK (15-20 KNOTS) DUE TO THE CONTINUED LAND INTERACTION AND AN
INCREASE IN VERTICAL WIND SHEAR. DYNAMIC MODELS ARE IN GOOD
AGREEMENT WITH A WEST-SOUTHWESTWARD TRACK AND WEAKENING TREND. GFS
HAS TRACKED THE SYSTEM NORTH OVER WATER IN THE LATEST RUN, IN WHICH
THERE WOULD BE A SMALL POSSIBILITY OF REGENERATION, BUT THIS SEEMS
UNLIKELY DUE TO THE WEAKENING TREND, CURRENT STORM MOTION AND
INCREASING VERTICAL WIND SHEAR. THIS IS THE FINAL WARNING ON THIS
SYSTEM BY THE JOINT TYPHOON WRNCEN PEARL HARBOR HI. THE SYSTEM WILL
BE CLOSELY MONITORED FOR SIGNS OF REGENERATION.//