Tropical Cyclones [Index]

Tropical Cyclone 201202 Southern Hemisphere Summary

WTXS21 PGTW 20111206 03:00z
MSGID/GENADMIN/NAVMARFCSTCEN PEARL HARBOR HI/JTWC//
SUBJ/TROPICAL CYCLONE FORMATION ALERT//
RMKS/
1. FORMATION OF A SIGNIFICANT TROPICAL CYCLONE IS POSSIBLE WITHIN
120 NM EITHER SIDE OF A LINE FROM 16.9S 69.9E TO 17.5S 65.5E
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 IM-
AGERY AT 060000Z INDICATES THAT A CIRCULATION CENTER IS LOCATED
NEAR 17.0S 69.6E.  THE SYSTEM IS MOVING WEST-SOUTHWESTWARD AT 06
KNOTS.
2. REMARKS: THE AREA OF CONVECTION PREVIOUSLY LOCATED NEAR 16.4S
69.9E, IS NOW LOCATED NEAR 17.0S 69.6E, APPROXIMATELY 830 NM EAST-
NORTHEAST OF LA REUNION. ANIMATED INFRARED SATELLITE IMAGERY SHOWS
CONVECTION DEEPENING AND CONSOLIDATING OVER THE LOW LEVEL
CIRCULATION CENTER (LLCC). AGENCY DVORAK ESTIMATES HAVE RISEN TO
BETWEEN 25 AND 35 KNOTS, AND A 060055Z SSMIS IMAGES REVEALS THICK
CURVED CONVECTIVE BANDING ORGANIZING AROUND THE LLCC. THE MOST
RECENT UPPER LEVEL ANALYSIS DEPICTS THE LLCC DIRECTLY UNDERNEATH THE
SUBTROPICAL RIDGE AXIS IN A REGION OF MINIMAL VERTICAL WIND SHEAR.
27 DEGREE SEA SURFACE TEMPERATURES ARE FAVORABLE FOR FURTHER
DEVELOPMENT. THE LATEST MODEL GUIDANCE, ALTHOUGH SPARSE, INDICATES
WESTWARD MOVEMENT FOR THE LLCC, WHICH WILL KEEP THE SYSTEM OVER WARM
WATERS. ANIMATED WATER VAPOR IMAGERY REVEALS SOME IMPINGEMENT ON
OUTFLOW OVER THE WESTERN SEMICIRCLE BUT GOOD OUTFLOW ELSEWHERE,
INCLUDING A DEVELOPING POLEWARD CHANNEL OVER THE SOUTHWEST
QUADRANT.  MAXIMUM SUSTAINED SURFACE WINDS ARE ESTIMATED AT 25 TO 30
KNOTS. MINIMUM SEA LEVEL PRESSURE IS ESTIMATED TO BE NEAR 1001 MB.
THE POTENTIAL FOR THE DEVELOPMENT OF A SIGNIFICANT TROPICAL CYCLONE
WITHIN THE NEXT 24 HOURS IS UPGRADED TO HIGH.
3. THIS ALERT WILL BE REISSUED, UPGRADED TO WARNING OR CANCELLED BY
070300Z.
=========================================================================
WTXS32 PGTW 20111206 09:00z
MSGID/GENADMIN/NAVMARFCSTCEN PEARL HARBOR HI/JTWC//
SUBJ/TROPICAL CYCLONE 02S (TWO) WARNING NR 001//
REF/A/MSG/NAVMARFCSTCEN PEARL HARBOR HI/060251ZDEC2011//
AMPN/REF A IS A TROPICAL CYCLONE FORMATION ALERT.//
RMKS/
1. TROPICAL CYCLONE 02S (TWO) WARNING NR 001
   02 ACTIVE TROPICAL CYCLONES IN SOUTHIO
   MAX SUSTAINED WINDS BASED ON ONE-MINUTE AVERAGE
   WIND RADII VALID OVER OPEN WATER ONLY
    ---
   WARNING POSITION:
   060600Z --- NEAR 17.2S 69.1E
     MOVEMENT PAST SIX HOURS - 230 DEGREES AT 05 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: 17.2S 69.1E
    ---
   FORECASTS:
   12 HRS, VALID AT:
   061800Z --- 17.6S 67.7E
   MAX SUSTAINED WINDS - 035 KT, GUSTS 045 KT
   WIND RADII VALID OVER OPEN WATER ONLY
   VECTOR TO 24 HR POSIT: 255 DEG/ 07 KTS
    ---
   24 HRS, VALID AT:
   070600Z --- 17.9S 66.3E
   MAX SUSTAINED WINDS - 040 KT, GUSTS 050 KT
   WIND RADII VALID OVER OPEN WATER ONLY
   RADIUS OF 034 KT WINDS - 040 NM NORTHEAST QUADRANT
                            040 NM SOUTHEAST QUADRANT
                            040 NM SOUTHWEST QUADRANT
                            040 NM NORTHWEST QUADRANT
   VECTOR TO 36 HR POSIT: 260 DEG/ 07 KTS
    ---
   36 HRS, VALID AT:
   071800Z --- 18.1S 64.9E
   MAX SUSTAINED WINDS - 040 KT, GUSTS 050 KT
   WIND RADII VALID OVER OPEN WATER ONLY
   RADIUS OF 034 KT WINDS - 040 NM NORTHEAST QUADRANT
                            040 NM SOUTHEAST QUADRANT
                            040 NM SOUTHWEST QUADRANT
                            040 NM NORTHWEST QUADRANT
   VECTOR TO 48 HR POSIT: 270 DEG/ 07 KTS
    ---
   EXTENDED OUTLOOK:
   48 HRS, VALID AT:
   080600Z --- 18.1S 63.5E
   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 72 HR POSIT: 270 DEG/ 04 KTS
    ---
   72 HRS, VALID AT:
   090600Z --- 18.1S 62.0E
   MAX SUSTAINED WINDS - 030 KT, GUSTS 040 KT
   WIND RADII VALID OVER OPEN WATER ONLY
   DISSIPATED AS A SIGNIFICANT TROPICAL CYCLONE OVER WATER
    ---
REMARKS:
060900Z POSITION NEAR 17.3S 68.7E.
TROPICAL CYCLONE (TC) 02S, LOCATED APPROXIMATELY 685 NM EAST-
NORTHEAST OF PORT LOUIS, HAS TRACKED SOUTHWESTWARD AT 05 KNOTS
OVER THE PAST SIX HOURS. ANIMATED MULTISPECTRAL SATELLITE IMAGERY
DEPICTS TIGHTLY-CURVED LOW-LEVEL BANDING WRAPPING INTO A WELL-
DEFINED LOW-LEVEL CIRCULATION CENTER (LLCC) WITH LIMITED DEEP
CONVECTION OVER THE EASTERN SEMI-CIRCLE. ANIMATED INFRARED SATELLITE
IMAGERY INDICATES THAT DEEP CONVECTIVE ORGANIZATION HAS WEAKENED
SINCE AN IMPRESSIVE, CONSOLIDATED SIGNATURE NEAR 06/0200Z (ALSO SEE
THE 052325Z SSMI). HOWEVER, A 060410Z ASCAT IMAGE (25-KM) SHOWS 30-
35 KNOT WINDS OVER THE SOUTHERN SEMI-CIRCLE SUPPORTING THE CURRENT
INTENSITY ASSESSMENT OF 35 KNOTS. DVORAK INTENSITY ESTIMATES ALSO
RANGE FROM 30-35 KNOTS. TC 02S IS FORECAST TO TRACK GENERALLY
WESTWARD UNDER THE STEERING INFLUENCE OF A LOW-LEVEL SUBTROPICAL
RIDGE (STR) SITUATED TO THE SOUTH. MODEL GUIDANCE IS LIMITED BUT IS
IN GOOD AGREEMENT THROUGH THE FORECAST PERIOD. TC 02S IS EXPECTED TO
INTENSIFY SLIGHTLY BUT SHOULD WEAKEN AND DISSIPATE BY TAU 72 DUE TO
INCREASING VERTICAL WIND SHEAR ASSOCIATED WITH STRONG WESTERLY FLOW.
THIS WARNING SUPERSEDES AND CANCELS REF A, NAVMARFCSTCEN 060251Z
DEC 11 TROPICAL CYCLONE FORMATION ALERT (WTXS21 PGTW 060300).
MAXIMUM SIGNIFICANT WAVE HEIGHT AT 060600Z IS 11 FEET. NEXT WARNINGS
AT 062100Z AND 070900Z. REFER TO TROPICAL CYCLONE 01S (ALENGA)
WARNINGS (WTXS31 PGTW) FOR TWELVE-HOURLY UPDATES.//
=========================================================================
WTXS32 PGTW 20121206 21:00z
MSGID/GENADMIN/NAVMARFCSTCEN PEARL HARBOR HI/JTWC//
SUBJ/TROPICAL CYCLONE 02S (TWO) WARNING NR 002//
RMKS/
1. TROPICAL CYCLONE 02S (TWO) WARNING NR 002
   02 ACTIVE TROPICAL CYCLONES IN SOUTHIO
   MAX SUSTAINED WINDS BASED ON ONE-MINUTE AVERAGE
   WIND RADII VALID OVER OPEN WATER ONLY
    ---
   WARNING POSITION:
   061800Z --- NEAR 17.5S 68.4E
     MOVEMENT PAST SIX HOURS - 215 DEGREES AT 05 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: 17.5S 68.4E
    ---
   FORECASTS:
   12 HRS, VALID AT:
   070600Z --- 17.9S 67.5E
   MAX SUSTAINED WINDS - 035 KT, GUSTS 045 KT
   WIND RADII VALID OVER OPEN WATER ONLY
   VECTOR TO 24 HR POSIT: 265 DEG/ 05 KTS
    ---
   24 HRS, VALID AT:
   071800Z --- 18.0S 66.5E
   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:
   080600Z --- 18.1S 65.5E
   MAX SUSTAINED WINDS - 035 KT, GUSTS 045 KT
   WIND RADII VALID OVER OPEN WATER ONLY
   VECTOR TO 48 HR POSIT: 270 DEG/ 05 KTS
    ---
   EXTENDED OUTLOOK:
   48 HRS, VALID AT:
   081800Z --- 18.1S 64.4E
   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: 285 DEG/ 05 KTS
    ---
   72 HRS, VALID AT:
   091800Z --- 17.6S 62.4E
   MAX SUSTAINED WINDS - 020 KT, GUSTS 030 KT
   WIND RADII VALID OVER OPEN WATER ONLY
   DISSIPATED AS A SIGNIFICANT TROPICAL CYCLONE OVER WATER
    ---
REMARKS:
062100Z POSITION NEAR 17.6S 68.2E.
TROPICAL CYCLONE (TC) 02S, LOCATED APPROXIMATELY 760 NM EAST-
NORTHEAST OF LA REUNION HAS TRACKED SOUTHWESTWARD AT 05 KNOTS OVER
THE PAST SIX HOURS. ANIMATED INFRARED SATELLITE IMAGERY OVER THE
PAST SIX HOURS SHOWS CONVECTIVE CLOUD TOPS COOLING AND STRETCHING.
THE SYSTEM IS EXHIBITING STRONG DIURNAL CYCLING AND STRUGGLING TO
INTENSIFY. A 061643Z ASCAT IMAGE DOES REVEAL A TIGHTLY ORGANIZED LOW
LEVEL CIRCULATION CENTER, HOWEVER, AS WELL AS A SIGNIFICANT BAND OF
30-35 KNOT WINDS OVER THE SOUTHWESTERN QUADRANT. ALTHOUGH AGENCY
DVORAK ASSESSMENTS HAVE FALLEN TO 25-35 KNOTS, THE CURRENT INTENSITY
REMAINS 35 KNOTS BASED ON THE ASCAT IMAGE. ANIMATED WATER VAPOR
IMAGERY INDICATES GOOD RADIAL OUTFLOW. THE 061200Z PGTW UPPER LEVEL
STREAMLINE ANALYSIS DEPICTS TC 02S JUST POLEWARD OF THE SUBTROPICAL
RIDGE AXIS BENEATH A REGION OF DIFFLUENT FLOW AND LOW VERTICAL WIND
SHEAR. ALONG-TRACK SEA SURFACE TEMPERATURES OF 27 DEGREES ARE
MINIMALLY SUPPORTIVE OF DEVELOPMENT. THE SLOW AND ERRATIC
DEVELOPMENT OF TC 02S, WHICH ORIGINATED AS A DISTURBANCE NINE DAYS
AGO, INDICATE THAT THE SYSTEM WILL MAINTAIN A RELATIVELY FLAT
INTENSITY TREND OVER THE NEXT 48 HOURS AS IT TRACKS WESTWARD. NEAR
TAU 48, SURGING UPPER LEVEL WESTERLIES SURING OVER MADAGASCAR AND
INTO THE SOUTHWEST INDIAN OCEAN WILL INCREASE VERTICAL WIND SHEAR
AND THE SYSTEM WILL DISSIPATE OVER WATER. MODEL GUIDANCE IS IN GOOD
AGREEMENT REGARDING BOTH TRACK AND INTENSITY. MAXIMUM SIGNIFICANT
WAVE HEIGHT AT 061800Z IS 11 FEET. NEXT WARNINGS AT 070900Z AND
072100Z. REFER TO TROPICAL CYCLONE 01S (ALENGA)WARNINGS (WTXS31 PGTW)
FOR TWELVE-HOURLY UPDATES.//
=========================================================================
WTXS32 PGTW 20111207 09:00z
MSGID/GENADMIN/NAVMARFCSTCEN PEARL HARBOR HI/JTWC//
SUBJ/TROPICAL CYCLONE 02S (TWO) WARNING NR 003//
RMKS/
1. TROPICAL CYCLONE 02S (TWO) WARNING NR 003
   02 ACTIVE TROPICAL CYCLONES IN SOUTHIO
   MAX SUSTAINED WINDS BASED ON ONE-MINUTE AVERAGE
   WIND RADII VALID OVER OPEN WATER ONLY
    ---
   WARNING POSITION:
   070600Z --- NEAR 16.3S 67.3E
     MOVEMENT PAST SIX HOURS - 270 DEGREES AT 05 KTS
     POSITION ACCURATE TO WITHIN 060 NM
     POSITION BASED ON CENTER LOCATED BY SATELLITE
   PRESENT WIND DISTRIBUTION:
   MAX SUSTAINED WINDS - 030 KT, GUSTS 040 KT
   WIND RADII VALID OVER OPEN WATER ONLY
   DISSIPATING AS A SIGNIFICANT TROPICAL CYCLONE OVER WATER
   REPEAT POSIT: 16.3S 67.3E
    ---
   FORECASTS:
   12 HRS, VALID AT:
   071800Z --- 16.4S 66.6E
   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 24 HR POSIT: 280 DEG/ 03 KTS
    ---
   24 HRS, VALID AT:
   080600Z --- 16.3S 66.0E
   MAX SUSTAINED WINDS - 025 KT, GUSTS 035 KT
   WIND RADII VALID OVER OPEN WATER ONLY
   DISSIPATED AS A SIGNIFICANT TROPICAL CYCLONE OVER WATER
    ---
REMARKS:
070900Z POSITION NEAR 16.3S 67.1E.
TROPICAL CYCLONE (TC) 02S, LOCATED APPROXIMATELY 605 NM SOUTH-
SOUTHWEST OF DIEGO GARCIA HAS TRACKED WESTWARD AT 05 KNOTS OVER THE
PAST SIX HOURS. ANIMATED MULTISPECTRAL SATELLITE IMAGERY REVEALS A
FULLY EXPOSED LOW LEVEL CIRCULATION CENTER (LLCC) WITH MINIMAL
CONVECTION TO THE SOUTH. A 070119Z CORIOLIS 37GHZ MICROWAVE IMAGE
SHOWS SHALLOW FRAGMENTED CONVECTION AROUND THE LLCC. THE INITIAL
INTENSITY IS BASED ON THE PGTW DVORAK ESTIMATE OF 25 TO 30 KNOTS AND
A 070117Z WINDSAT PASS DEPICTING 25-30 KNOT WINDS ALONG THE SOUTHERN
PERIPHERY OF THE LLCC. UPPER LEVEL ANALYSIS INDICATES THE SYSTEM IS
LOCATED DIRECTLY BENEATH THE SUBTROPICAL RIDGE AXIS, IN AN AREA OF
LOW (05-10 KNOT) VERTICAL WIND SHEAR. TC 02S IS CURRENTLY LOCATED
WITHIN A WEAK STEERING ENVIRONMENT, PRIMARILY DRIVEN BY A WEAK LOW-
TO MID-LEVEL STEERING RIDGE TO THE SOUTH OF THE SYSTEM. TC 02S
SHOULD CONTINUE TO TRACK SLOWLY WESTWARD AND WEAKEN AS IT ENCOUNTERS
INCREASED VERTICAL WIND SHEAR. MODEL GUIDANCE IS IN GOOD AGREEMENT
REGARDING BOTH TRACK AND INTENSITY. THIS IS THE FINAL WARNING ON
THIS SYSTEM BY THE JOINT TYPHOON WARNING CENTER (NAVMARFCSTCEN).
THE SYSTEM WILL BE CLOSELY MONITORED FOR SIGNS OF REGENERATION.
MAXIMUM SIGNIFICANT WAVE HEIGHT AT 070600Z IS 12 FEET.
REFER TO TROPICAL CYCLONE 01S (ALENGA) WARNINGS (WTXS31 PGTW)
FOR TWELVE-HOURLY UPDATES.//