Tropical Cyclones [Index]

Tropical Cyclone CHANDA Southern Hemisphere Summary

WTXS21 PGTW 201206 19:30z
MSGID/GENADMIN/NAVMARFCSTCEN PEARL HARBOR HI/JTWC//
SUBJ/TROPICAL CYCLONE FORMATION ALERT//
RMKS/
1. FORMATION OF A SIGNIFICANT TROPICAL CYCLONE IS POSSIBLE WITHIN
185 NM EITHER SIDE OF A LINE FROM 16.0S 40.2E TO 21.1S 44.1E
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 IM-
AGERY AT 061830Z INDICATES THAT A CIRCULATION CENTER IS LOCATED
NEAR 16.5S 40.7E.  THE SYSTEM IS MOVING WEST-SOUTHWESTWARD AT 02
KNOTS.
2. REMARKS: THE AREA OF CONVECTION PREVIOUSLY LOCATED NEAR 15.2S
43.0E, IS NOW LOCATED NEAR 16.2S 41.0E, APPROXIMATELY 380 NM WEST-
NORTHWEST OF ANTANANARIVO, MADAGASCAR. ANIMATED INFRARED SATELLITE
IMAGERY SHOWS A BROAD AREA OF FLARING CONVECTION LOCATED OVER A
CONSOLIDATING LOW LEVEL CIRCULATION CENTER (LLCC). UPPER LEVEL
ANALYSIS INDICATES THAT THE DISTURBANCE IS LOCATED IN A DIFFLUENT
REGION, WITH LOW (10 KNOT) VERTICAL WIND SHEAR. THE LLCC LIES
DIRECTLY BENEATH THE SUBTROPICAL RIDGE AXIS, PROVIDING AMPLE DUAL
CHANNEL OUTFLOW,PARTICULARLY ON THE EQUATORWARD SIDE. A 061715Z
SSMIS MICROWAVE IMAGE REVEALS BANDING STRUCTURES ARE BECOMING MORE
ORGANIZED AND DEEP CONVECTION IS WRAPPING AROUND THE LLCC ALONG THE
EASTERN SEMICIRCLE.  NUMERICAL MODEL GUIDANCE DEVELOPS THIS SYSTEM
FAIRLY AGGRESSIVELY OVER THE NEXT 24 HOURS. SEA SURFACE TEMPERATURES
IN THE REGION REMAIN FAVORABLE AT APPROXIMATELY 29 TO 30 DEGREES
CELSIUS. MAXIMUM SUSTAINED SURFACE WINDS ARE ESTIMATED AT 27 TO 32
KNOTS. MINIMUM SEA LEVEL PRESSURE IS ESTIMATED TO BE NEAR 1000 MB.
DUE TO INCREASED CONSOLIDATION OF THE LLCC AND THE IMPROVED
CONVECTIVE BANDING, 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
071930Z.
=========================================================================
WTXS31 PGTW 20120107 21:00z
MSGID/GENADMIN/NAVMARFCSTCEN PEARL HARBOR HI/JTWC//
SUBJ/TROPICAL CYCLONE 05S (FIVE) WARNING NR 001//
REF/A/NAVMARFCSTCEN PEARL HARBOR HI/061921Z JAN 12//
AMPN/TROPICAL CYCLONE FORMATION ALERT//
1. TROPICAL CYCLONE 05S (FIVE) 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:
   071800Z --- NEAR 18.4S 41.3E
     MOVEMENT PAST SIX HOURS - 160 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: 18.4S 41.3E
    ---
   FORECASTS:
   12 HRS, VALID AT:
   080600Z --- 19.1S 42.0E
   MAX SUSTAINED WINDS - 040 KT, GUSTS 050 KT
   WIND RADII VALID OVER OPEN WATER ONLY
   RADIUS OF 034 KT WINDS - 035 NM NORTHEAST QUADRANT
                            040 NM SOUTHEAST QUADRANT
                            040 NM SOUTHWEST QUADRANT
                            035 NM NORTHWEST QUADRANT
   VECTOR TO 24 HR POSIT: 140 DEG/ 05 KTS
    ---
   24 HRS, VALID AT:
   081800Z --- 19.9S 42.7E
   MAX SUSTAINED WINDS - 045 KT, GUSTS 055 KT
   WIND RADII VALID OVER OPEN WATER ONLY
   RADIUS OF 034 KT WINDS - 040 NM NORTHEAST QUADRANT
                            045 NM SOUTHEAST QUADRANT
                            045 NM SOUTHWEST QUADRANT
                            040 NM NORTHWEST QUADRANT
   VECTOR TO 36 HR POSIT: 140 DEG/ 07 KTS
    ---
   36 HRS, VALID AT:
   090600Z --- 20.9S 43.6E
   MAX SUSTAINED WINDS - 045 KT, GUSTS 055 KT
   WIND RADII VALID OVER OPEN WATER ONLY
   RADIUS OF 034 KT WINDS - 040 NM NORTHEAST QUADRANT
                            045 NM SOUTHEAST QUADRANT
                            045 NM SOUTHWEST QUADRANT
                            040 NM NORTHWEST QUADRANT
   VECTOR TO 48 HR POSIT: 130 DEG/ 07 KTS
    ---
   EXTENDED OUTLOOK:
   48 HRS, VALID AT:
   091800Z --- 21.8S 44.7E
   MAX SUSTAINED WINDS - 035 KT, GUSTS 045 KT
   WIND RADII VALID OVER OPEN WATER ONLY
   DISSIPATING AS A SIGNIFICANT TROPICAL CYCLONE OVER LAND
   VECTOR TO 72 HR POSIT: 105 DEG/ 06 KTS
    ---
   72 HRS, VALID AT:
   101800Z --- 22.4S 47.2E
   MAX SUSTAINED WINDS - 030 KT, GUSTS 040 KT
   WIND RADII VALID OVER OPEN WATER ONLY
   DISSIPATED AS A SIGNIFICANT TROPICAL CYCLONE OVER LAND
    ---
REMARKS:
072100Z POSITION NEAR 18.6S 41.5E.
TROPICAL CYCLONE (TC) 05S LOCATED APPROXIMATELY 330 NM WEST OF
ANTANANARIVO, MADAGASCAR, HAS TRACKED SOUTH-SOUTHEASTWARD AT 05
KNOTS DURING THE PAST SIX HOURS. ANIMATED INFRARED SATELLITE IMAGERY
SHOWS AN ELONGATED AREA OF FLARING CONVECTION LOCATED OVER A LOW
LEVEL CIRCULATION CENTER (LLCC). THE CURRENT POSITION AND INTENSITY
ARE BASED ON THE PGTW FIX AND DVORAK ESTIMATE OF 35 KNOTS,
RESPECTIVELY. UPPER LEVEL ANALYSIS INDICATES THAT TC 05S IS LOCATED
IN A DIFFLUENT REGION 5 DEGREES TO THE SOUTH OF A RIDGE AXIS.
HOWEVER, THE UPPER LEVEL WESTERLIES ARE IN CONTRAST TO THE LOW LEVEL
EASTERLIES PROVIDING MODERATE (10-15 KNOT) VERTICAL WIND SHEAR
(VWS). AS A RESULT OF THE VWS, THE DEEP CONVECTION IS DISPLACED
EASTWARD OF THE LLCC, HAMPERING DEVELOPMENT IN AN OTHERWISE
FAVORABLE ENVIRONMENT. ANIMATED WATER VAPOR IMAGERY REVEALS THAT
DESPITE THE VWS, THE SYSTEM IS BENEFITTING FROM AMPLE DUAL-CHANNEL
OUTFLOW. ADDITIONALLY, SEA SURFACE TEMPERATURES ARE FAVORABLE AT AN
ESTIMATED 28-29 DEGREES CELSIUS. 071507Z SSMIS 91GHZ MICROWAVE IMAGE
REVEALS CLEAR LOW-LEVEL BANDING STRUCTURES SPIRALING INTO THE LLCC,
WITH A FRAGMENTED DEEP CONVECTION WRAPPING AROUND THE EASTERN
PERIPHERY. TC 05S IS EXPECTED TO TRACK SOUTHEASTWARD AS IT MOVES
ALONG THE PERIPHERY OF A LOW- TO MID-LEVEL STEERING RIDGE TO THE
NORTH AND SHOULD INTENSIFY SLIGHTLY PRIOR TO MAKING LANDFALL ON
MADAGASCAR AFTER WHICH TC 05S WILL DISSIPATE. THE NUMERICAL MODEL
GUIDANCE IS IN GOOD AGREEMENT WITH THIS SCENARIO, AND THE FORECAST
TRACK IS IN LINE WITH CONSENSUS. MAXIMUM SIGNIFICANT WAVE HEIGHT AT
071800Z IS 11 FEET. NEXT WARNINGS AT 080900Z AND 082100Z. THIS
WARNING SUPERSEDES AND CANCELS REF A (WTXS21 PGTW 061930).//
=========================================================================
WTXS31 PGTW 20120108 09:00z
MSGID/GENADMIN/NAVMARFCSTCEN PEARL HARBOR HI/JTWC//
SUBJ/TROPICAL CYCLONE 05S (FIVE) WARNING NR 002//
1. TROPICAL CYCLONE 05S (FIVE) 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:
   080600Z --- NEAR 19.0S 42.1E
     MOVEMENT PAST SIX HOURS - 120 DEGREES AT 06 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: 19.0S 42.1E
    ---
   FORECASTS:
   12 HRS, VALID AT:
   081800Z --- 20.1S 42.8E
   MAX SUSTAINED WINDS - 040 KT, GUSTS 050 KT
   WIND RADII VALID OVER OPEN WATER ONLY
   RADIUS OF 034 KT WINDS - 035 NM NORTHEAST QUADRANT
                            040 NM SOUTHEAST QUADRANT
                            040 NM SOUTHWEST QUADRANT
                            035 NM NORTHWEST QUADRANT
   VECTOR TO 24 HR POSIT: 135 DEG/ 06 KTS
    ---
   24 HRS, VALID AT:
   090600Z --- 21.0S 43.7E
   MAX SUSTAINED WINDS - 045 KT, GUSTS 055 KT
   WIND RADII VALID OVER OPEN WATER ONLY
   RADIUS OF 034 KT WINDS - 040 NM NORTHEAST QUADRANT
                            045 NM SOUTHEAST QUADRANT
                            045 NM SOUTHWEST QUADRANT
                            040 NM NORTHWEST QUADRANT
   VECTOR TO 36 HR POSIT: 130 DEG/ 05 KTS
    ---
   36 HRS, VALID AT:
   091800Z --- 21.6S 44.5E
   MAX SUSTAINED WINDS - 035 KT, GUSTS 045 KT
   WIND RADII VALID OVER OPEN WATER ONLY
   DISSIPATING AS A SIGNIFICANT TROPICAL CYCLONE OVER LAND
   VECTOR TO 48 HR POSIT: 115 DEG/ 06 KTS
    ---
   EXTENDED OUTLOOK:
   48 HRS, VALID AT:
   100600Z --- 22.1S 45.6E
   MAX SUSTAINED WINDS - 030 KT, GUSTS 040 KT
   WIND RADII VALID OVER OPEN WATER ONLY
   DISSIPATED AS A SIGNIFICANT TROPICAL CYCLONE OVER LAND
    ---
REMARKS:
080900Z POSITION NEAR 19.3S 42.3E.
TROPICAL CYCLONE (TC) 05S, LOCATED APPROXIMATELY 270 NM WEST OF
ANTANANARIVO, MADAGASCAR, HAD TRACKED EAST-SOUTHEASTWARD AT 06
KNOTS DURING THE PAST SIX HOURS. RECENT ANIMATED MULTISPECTRAL
SATELLITE IMAGERY SHOWS AN IRREGULAR CENTRAL DENSE OVERCAST
OBSCURING THE LOW-LEVEL CIRCULATION CENTER (LLCC) WITH MULTIPLE
FORMATIVE FEEDER BANDS TO THE NORTH AND EAST. THE CURRENT POSITION
IS BASED ON THE PGTW CENTER FIX WITH POOR CONFIDENCE DUE TO THE
BECLOUDED LLCC AND LACK OF RECENT APPLICABLE MICROWAVE IMAGERY. THE
CURRENT INTENSITY IS BASED ON AGREEABLE DVORAK ESTIMATES OF 35 KNOTS
FROM PGTW, KNES, AND FMEE. UPPER-LEVEL ANALYSIS INDICATES THAT TC
05S IS LOCATED JUST POLEWARD OF A POINT SOURCE OF DIFFLUENCE UNDER
WEAK VERTICAL WIND SHEAR AND EXCELLENT DIVERGENCE ALOFT. ANIMATED
WATER VAPOR IMAGERY SHOWS SUSTAINED DUAL-CHANNEL OUTFLOW INTO CROSS
EQUATORIAL FLOW TO THE NORTH AND STRONG WESTERLY FLOW TO THE SOUTH,
WHICH IS FURTHER ENHANCED BY A DEEP MID-LATITUDE TROUGH LOCATED
FURTHER TO THE EAST OF THE LLCC. TC 05S IS CURRENTLY BEING STEERED
BY THE SOUTHWESTERN PERIPHERY OF A MID- TO UPPER-LEVEL SUBTROPICAL
RIDGE, AND WILL CONTINUE UNDER THIS STEERING INFLUENCE FOR THE
REMAINDER OF THE FORECAST PERIOD. AS UPPER- AND LOWER-LEVEL
CONDITIONS MAINTAIN A FAVORABLE ENVIRONMENT FOR TC 05S, THE SYSTEM
WILL CONTINUE TO INTENSIFY TO 45 KNOTS BY TAU 24, JUST BEFORE MAKING
LANDFALL OVER WEST-CENTRAL MADAGASCAR. DURING TAUS 36-48, TC 05S
SHOULD GRADUALLY DISSIPATE OVERLAND DUE TO LAND INTERACTION AND
FRICTIONAL FORCES BETWEEN THE LLCC AND THE APPROXIMATELY 3,000 FOOT
MOUNTAIN RANGES OF CENTRAL-EASTERN MADAGASCAR. THE MODEL CONSENSUS
IS BEING SKEWED BY THE SUDDEN POLEWARD TRACK OF THE EGRR AND WESTERN
TRACK PORTRAYED BY THE FLUCTUATING GFDN. THEREFORE, THE OFFICIAL
FORECAST LIES SLIGHTLY TO THE RIGHT OF CONSENSUS AND FASTER TO
OFFSET THE NOTED DISCREPANCIES. MAXIMUM SIGNIFICANT WAVE HEIGHT AT
080600Z IS 12 FEET. NEXT WARNINGS AT 082100Z AND 090900Z.//
=========================================================================
WTXS31 PGTW 20120108 21:00z
MSGID/GENADMIN/NAVMARFCSTCEN PEARL HARBOR HI/JTWC//
SUBJ/TROPICAL CYCLONE 05S (CHANDA) WARNING NR 003//
1. TROPICAL CYCLONE 05S (CHANDA) 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:
   081800Z --- NEAR 20.3S 43.8E
     MOVEMENT PAST SIX HOURS - 130 DEGREES AT 06 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: 20.3S 43.8E
    ---
   FORECASTS:
   12 HRS, VALID AT:
   090600Z --- 21.2S 44.6E
   MAX SUSTAINED WINDS - 030 KT, GUSTS 040 KT
   WIND RADII VALID OVER OPEN WATER ONLY
   DISSIPATED AS A SIGNIFICANT TROPICAL CYCLONE OVER LAND
    ---
REMARKS:
082100Z POSITION NEAR 20.5S 44.0E.
TROPICAL CYCLONE (TC) 05S (CHANDA), LOCATED APPROXIMATELY 200 NM
WEST-SOUTHWEST OF ANTANANARIVO, MADAGASCAR, HAS TRACKED
SOUTHEASTWARD AT 06 KNOTS OVER THE PAST SIX HOURS. THE LOW LEVEL
CIRCULATION CENTER (LLCC) IS NOW APPROXIMATELY 25 NM FROM THE COAST
OF MADAGASCAR. ANIMATED INFRARED SATELLITE IMAGERY REVEALS THAT THE
CENTRAL DEEP CONVECTION AROUND THE LLCC HAS SIGNIFICANTLY DEGRADED
AS TC 05S INTERACTS WITH LAND. THE CURRENT POSITION AND INTENSITY
ESTIMATES ARE BASED ON AGREEABLE FIXES FROM PGTW, KNES AND FMEE. TC
05S IS EXPECTED TO CONTINUE TO WEAKEN AS IT TRACKS OVER THE TERRAIN
OF MADAGASCAR. THE AVAILABLE MODEL GUIDANCE IS IN AGREEMENT WITH
THIS SCENARIO. 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 081800Z IS 11 FEET.//