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Tropical Cyclone GABRIELLE : JTWC Advisories
Season 2008-2009 Summaries (Operational Data): [AU] [SIO] [SPAC] [SH]
---> Tropical Cyclone GABRIELLE Track Map and Data

WTXS21 PGTW 20090301 14:00z
SUBJ/TROPICAL CYCLONE FORMATION ALERT//
RMKS/
1. FORMATION OF A SIGNIFICANT TROPICAL CYCLONE IS POSSIBLE WITHIN
180 NM EITHER SIDE OF A LINE FROM 11.6S 102.6E TO 15.0S 107.2E
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 IM-
AGERY AT 011300Z INDICATES THAT A CIRCULATION CENTER IS LOCATED
NEAR 12.1S 103.3E. THE SYSTEM IS MOVING SOUTHEASTWARD AT 14
KNOTS.
2. REMARKS: THE AREA OF CONVECTION PREVIOUSLY LOCATED NEAR 11.0S
101.1E, IS NOW LOCATED NEAR 12.1S 103.3E, APPROXIMATELY 375 NM EAST
OF COCOS ISLAND. ANIMATED MULTISPECTRAL SATELLITE IMAGERY DEPICTS A
WELL-DEFINED, EXPOSED LOW-LEVEL CIRCULATION CENTER (LLCC) WITH DEEP
CONVECTION RE-DEVELOPING JUST WEST OF THE CENTER. A 01/1226Z SSMIS
IMAGE INDICATED AN IMPROVING LLCC WITH ISOLATED CONVECTION NEAR
THE CENTER. EARLIER SCATTEROMETER SUPPORTS 25-30 KNOT WINDS WRAPPING
INTO THE CENTER. HIGH VERTICAL WIND SHEAR (VWS) REMAINS THE PRIMARY
LIMITING FACTOR WITH 30-40 KNOTS OVER THE SYSTEM. HOWEVER, VWS IS
EXPECTED TO DECREASE SIGNIFICANTLY WITHIN THE NEXT 12 HOURS AS THE
SYSTEM BEGINS TO TURN SOUTHEASTWARD, TRACKING UNDER THE UPPER-
LEVEL RIDGE AXIS AND REDUCED VWS. ADDITIONALLY, AN APPROACHING
SHORTWAVE TROUGH CURRENTLY SOUTHWEST OF THE SYSTEM IS FORECAST TO
SHIFT EAST PROVIDING AN IMPROVED POLEWARD OUTFLOW CHANNEL WITHIN
THE NEXT 24 HOURS. SST AND OCEAN HEAT CONTENT ARE FAVORABLE FOR
FURTHER DEVELOPMENT. MAXIMUM SUSTAINED SURFACE WINDS ARE ESTIMATED
AT 25 TO 30 KNOTS. MINIMUM SEA LEVEL PRESSURE IS ESTIMATED TO BE
NEAR 1002 MB. BASED ON THE FORECAST TRACK SOUTHEASTWARD TO SOUTH-
WARD, THE POTENTIAL FOR THE DEVELOPMENT OF A SIGNIFICANT TROPICAL
CYCLONE WITHIN THE NEXT 24 HOURS IS GOOD.
3. THIS ALERT WILL BE REISSUED, UPGRADED TO WARNING OR CANCELLED
BY 021400Z.//
=========================================================================
WTXS31 PGTW 20090302 03:00z COR
MSGID/GENADMIN/NAVMARFCSTCEN PEARL HARBOR HI/JTWC//
SUBJ/TROPICAL CYCLONE 17S (SEVENTEEN) WARNING NR 001 CORRECTED//
RMKS/
1. TROPICAL CYCLONE 17S (SEVENTEEN) WARNING NR 001A CORRECTED
   01 ACTIVE TROPICAL CYCLONE IN SOUTHIO
   MAX SUSTAINED WINDS BASED ON ONE-MINUTE AVERAGE
    ---
   WARNING POSITION:
   020000Z --- NEAR 13.2S 105.6E
     MOVEMENT PAST SIX HOURS - 115 DEGREES AT 11 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: 13.2S 105.6E
    ---
   FORECASTS:
   12 HRS, VALID AT:
   021200Z --- 14.2S 107.1E
   MAX SUSTAINED WINDS - 040 KT, GUSTS 050 KT
   WIND RADII VALID OVER OPEN WATER ONLY
   RADIUS OF 034 KT WINDS - 050 NM NORTHEAST QUADRANT
                            050 NM SOUTHEAST QUADRANT
                            050 NM SOUTHWEST QUADRANT
                            050 NM NORTHWEST QUADRANT
   VECTOR TO 24 HR POSIT: 180 DEG/ 04 KTS
    ---
   24 HRS, VALID AT:
   030000Z --- 15.0S 107.1E
   MAX SUSTAINED WINDS - 045 KT, GUSTS 055 KT
   WIND RADII VALID OVER OPEN WATER ONLY
   RADIUS OF 034 KT WINDS - 055 NM NORTHEAST QUADRANT
                            055 NM SOUTHEAST QUADRANT
                            055 NM SOUTHWEST QUADRANT
                            055 NM NORTHWEST QUADRANT
   VECTOR TO 36 HR POSIT: 245 DEG/ 05 KTS
    ---
   36 HRS, VALID AT:
   031200Z --- 15.4S 106.2E
   MAX SUSTAINED WINDS - 050 KT, GUSTS 065 KT
   WIND RADII VALID OVER OPEN WATER ONLY
   RADIUS OF 034 KT WINDS - 055 NM NORTHEAST QUADRANT
                            055 NM SOUTHEAST QUADRANT
                            055 NM SOUTHWEST QUADRANT
                            055 NM NORTHWEST QUADRANT
   VECTOR TO 48 HR POSIT: 245 DEG/ 07 KTS
    ---
   EXTENDED OUTLOOK:
   48 HRS, VALID AT:
   040000Z --- 16.0S 104.9E
   MAX SUSTAINED WINDS - 045 KT, GUSTS 055 KT
   WIND RADII VALID OVER OPEN WATER ONLY
   RADIUS OF 034 KT WINDS - 050 NM NORTHEAST QUADRANT
                            050 NM SOUTHEAST QUADRANT
                            050 NM SOUTHWEST QUADRANT
                            050 NM NORTHWEST QUADRANT
    ---
REMARKS:
020300Z POSITION NEAR 13.5S 106.0E.
TROPICAL CYCLONE (TC) 17S (SEVENTEEN), LOCATED APPROXIMATELY 515 NM
EAST OF THE COCOS ISLANDS HAS TRACKED EAST-SOUTHEASTWARD AT 11 KNOTS
OVER THE PAST 06 HOURS. THE CYCLONE HAS A WELL DEFINED LOW-LEVEL
CIRCULATION CENTER (LLCC) AND DVORAK ESTIMATES SUGGEST THE 35-KNOT
THRESHOLD HAS BEEN REACHED. A 01/2243Z SSMI/S IMAGE CONTINUES TO
SHOW THE MAIN CONVECTION SHEARED TO THE SOUTHWEST OF THE LLCC.
TC 17S HAS BEEN TRACKING EAST-SOUTHEASTWARD IN RESPONSE TO A
MIDLATITUDE TROUGH WEST OF AUSTRALIA. BY TAU 24, THIS TROUGH WILL
MOVE EASTWARD, ALLOWING AN ANTICYCLONE TO BUILD IN SOUTH OF THE
SYSTEM. THIS ANTICYCLONE WILL CAUSE TC 17S TO TURN BACK TO THE WEST.
TC 17S IS CURRENT IN A REGION OF MODERATE VERTICAL WIND SHEAR.
HOWEVER, AS THE PREVIOUSLY MENTIONED MIDLATITUDE TROUGH MOVES
OUT, THE WIND SHEAR GRADIENT IS FORECAST TO RELAX, ALLOWING FOR
SLOW INTENSIFICATION THROUGH THE FORECAST PERIOD. THE AVAILABLE
OBJECTIVE AIDS ARE IN GOOD AGREEMENT WITH THE TRACK FORECAST.
THIS WARNING SUPERSEDES AND CANCELS REF A, NAVMARFCSTCEN 011351Z
MAR 09 TROPICAL CYCLONE FORMATION ALERT (WTXS21 PGTW 011400 )
MAXIMUM SIGNIFICANT WAVE HEIGHT AT 020000Z IS 12 FEET.
NEXT WARNINGS AT 021500Z AND 030300Z. JUSTIFICATION FOR CORRECTION:
CHANGED DIRECTION CONVECTION WAS SHEARED FROM SOUTHEAST TO SOUTHWEST.
=========================================================================
WTXS31 PGTW 20090302 15:00z
SUBJ:  TROPICAL CYCLONE 17S (GABRIELLE) WARNING NR 002
1. TROPICAL CYCLONE 17S (GABRIELLE) WARNING NR 002
   01 ACTIVE TROPICAL CYCLONE IN SOUTHIO
   MAX SUSTAINED WINDS BASED ON ONE-MINUTE AVERAGE
    ---
   WARNING POSITION:
   021200Z --- NEAR 14.4S 106.5E
     MOVEMENT PAST SIX HOURS - 130 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: 14.4S 106.5E
    ---
   FORECASTS:
   12 HRS, VALID AT:
   030000Z --- 14.9S 106.9E
   MAX SUSTAINED WINDS - 040 KT, GUSTS 050 KT
   WIND RADII VALID OVER OPEN WATER ONLY
   RADIUS OF 034 KT WINDS - 050 NM NORTHEAST QUADRANT
                            050 NM SOUTHEAST QUADRANT
                            050 NM SOUTHWEST QUADRANT
                            050 NM NORTHWEST QUADRANT
   VECTOR TO 24 HR POSIT: 225 DEG/ 04 KTS
    ---
   24 HRS, VALID AT:
   031200Z --- 15.5S 106.3E
   MAX SUSTAINED WINDS - 045 KT, GUSTS 055 KT
   WIND RADII VALID OVER OPEN WATER ONLY
   RADIUS OF 034 KT WINDS - 055 NM NORTHEAST QUADRANT
                            065 NM SOUTHEAST QUADRANT
                            065 NM SOUTHWEST QUADRANT
                            055 NM NORTHWEST QUADRANT
   VECTOR TO 36 HR POSIT: 245 DEG/ 08 KTS
    ---
   36 HRS, VALID AT:
   040000Z --- 16.1S 104.8E
   MAX SUSTAINED WINDS - 050 KT, GUSTS 065 KT
   WIND RADII VALID OVER OPEN WATER ONLY
   RADIUS OF 034 KT WINDS - 055 NM NORTHEAST QUADRANT
                            065 NM SOUTHEAST QUADRANT
                            065 NM SOUTHWEST QUADRANT
                            055 NM NORTHWEST QUADRANT
   VECTOR TO 48 HR POSIT: 245 DEG/ 10 KTS
    ---
   EXTENDED OUTLOOK:
   48 HRS, VALID AT:
   041200Z --- 16.9S 102.9E
   MAX SUSTAINED WINDS - 045 KT, GUSTS 055 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
    ---
REMARKS:
021500Z POSITION NEAR 14.5S 106.6E.
TROPICAL CYCLONE (TC) 17S (GABRIELLE), LOCATED APPROXIMATELY 565 NM
EAST-SOUTHEAST OF THE COCOS ISLANDS HAS TRACKED SOUTHEASTWARD AT 05
KNOTS OVER THE PAST 06 HOURS. ANIMATED INFRARED SATELLITE IMAGERY
AND A 021212Z SSMI/S IMAGE DEPICT A STRUGGLING SYSTEM WITH A PART-
IALLY EXPOSED LOW-LEVEL CIRCULATION CENTER (LLCC) WITH WEAK DEEP
CONVECTIVE BANDING WRAPPING INTO THE WESTERN QUADRANT OF THE STORM.
A 021114Z QUIKSCAT IMAGE INDICATES 30-35 KNOT UNFLAGGED WINDS OVER
THE WESTERN SEMI-CIRCLE, WHICH ALONG WITH DVORAK INTENSITY ESTIMATES
RANGING FROM 35-45 KNOTS, SUPPORT THE CURRENT INTENSITY OF 35 KNOTS.
AS EXPECTED, THE SYSTEM HAS MOVED UNDER THE UPPER-LEVEL SUBTROPICAL
RIDGE AXIS AND INTO LOWER VERTICAL WIND SHEAR (10-20 KNOTS), HOW-
EVER, OVERALL OUTFLOW HAS REMAINED WEAK. ANIMATED WATER VAPOR
IMAGERY SHOWS A WEAK POLEWARD OUTFLOW CHANNEL, ENHANCED SLIGHTLY BY
A FILLING MIDLATITUDE SHORTWAVE TROUGH PROPAGATING INTO SOUTHWEST
AUSTRALIA. DUE TO THIS WEAKENING TROUGH, THE LOW- TO MID-LEVEL
SUBTROPICAL STEERING RIDGE IS EXPECTED TO STRENGTHEN SOUTH OF THE
SYSTEM IN THE NEXT 12 HOURS AND WILL ALLOW THE SYSTEM TO CONTINUE
SLOWING AND TO TRACK WEST-SOUTHWESTWARD (AND ACCELERATE). THE
AVAILABLE DYNAMIC GUIDANCE IS IN GOOD AGREEMENT WITH THIS TRACK.
THE SYSTEM IS FORECAST TO SLOWLY INTENSIFY OVER THE NEXT 36 HOURS
UNTIL IT TRACKS INTO COOLER SST BY 48. MAXIMUM SIGNIFICANT WAVE
HEIGHT AT 021200Z IS 14 FEET. NEXT WARNINGS AT 030300Z AND
031500Z.//
=========================================================================
WTXS31 PGTW 20090303 03:00z
MSGID/GENADMIN/NAVMARFCSTCEN PEARL HARBOR HI/JTWC//
SUBJ/TROPICAL CYCLONE 17S (GABRIELLE) WARNING NR 003//
RMKS/
1. TROPICAL CYCLONE 17S (GABRIELLE) WARNING NR 003
   01 ACTIVE TROPICAL CYCLONE IN SOUTHIO
   MAX SUSTAINED WINDS BASED ON ONE-MINUTE AVERAGE
    ---
   WARNING POSITION:
   030000Z --- NEAR 13.7S 107.5E
     MOVEMENT PAST SIX HOURS - 090 DEGREES AT 03 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
   REPEAT POSIT: 13.7S 107.5E
    ---
   FORECASTS:
   12 HRS, VALID AT:
   031200Z --- 14.5S 107.9E
   MAX SUSTAINED WINDS - 040 KT, GUSTS 050 KT
   WIND RADII VALID OVER OPEN WATER ONLY
   RADIUS OF 034 KT WINDS - 050 NM NORTHEAST QUADRANT
                            050 NM SOUTHEAST QUADRANT
                            050 NM SOUTHWEST QUADRANT
                            050 NM NORTHWEST QUADRANT
   VECTOR TO 24 HR POSIT: 235 DEG/ 08 KTS
    ---
   24 HRS, VALID AT:
   040000Z --- 15.4S 106.6E
   MAX SUSTAINED WINDS - 045 KT, GUSTS 055 KT
   WIND RADII VALID OVER OPEN WATER ONLY
   RADIUS OF 034 KT WINDS - 055 NM NORTHEAST QUADRANT
                            065 NM SOUTHEAST QUADRANT
                            065 NM SOUTHWEST QUADRANT
                            055 NM NORTHWEST QUADRANT
   VECTOR TO 36 HR POSIT: 245 DEG/ 10 KTS
    ---
   36 HRS, VALID AT:
   041200Z --- 16.2S 104.7E
   MAX SUSTAINED WINDS - 050 KT, GUSTS 065 KT
   WIND RADII VALID OVER OPEN WATER ONLY
   RADIUS OF 034 KT WINDS - 055 NM NORTHEAST QUADRANT
                            065 NM SOUTHEAST QUADRANT
                            065 NM SOUTHWEST QUADRANT
                            055 NM NORTHWEST QUADRANT
   VECTOR TO 48 HR POSIT: 235 DEG/ 16 KTS
    ---
   EXTENDED OUTLOOK:
   48 HRS, VALID AT:
   050000Z --- 18.0S 102.0E
   MAX SUSTAINED WINDS - 045 KT, GUSTS 055 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
    ---
REMARKS:
030300Z POSITION NEAR 13.9S 107.6E.
TROPICAL CYCLONE (TC) 17S (GABRIELLE), LOCATED APPROXIMATELY 630 NM
EAST OF THE COCOS ISLANDS HAS TRACKED EASTWARD AT 03 KNOTS OVER THE
PAST 06 HOURS. ANIMATED INFRARED SATELLITE IMAGERY AND A 022231Z
SSMI/S IMAGE INDICATE THE LOW LEVEL CIRCULATION CENTER (LLCC) HAD
BECOME COMPLETELY EXPOSED OVER THE PAST 12 HOURS, BUT IN THE PAST 4
TO 6 HOURS HAS TRACKED TOWARDS DEEPENING CONVECTION THAT HAS QUICKLY
STARTED TO ORGANIZE. THE LLCC HAS BEEN ABLE TO MAINTAIN ITS
STRUCTURE AND AN EDGE OF SWATH QUIKSCAT PASS INDICATES 30-35 KNOTS
OF UNFLAGGED WINDS ON THE WESTERN PERIPHERY. UPPER LEVEL ANALYSIS
INDICATES TC 17S IS UNDER THE AXIS OF AN UPPER LEVEL SUBTROPICAL
RIDGE, PROVIDING AN ENVIRONMENT WITH DECREASING VERTICAL WIND SHEAR
AND A RAPIDLY DEVELOPING POLEWARD OUTFLOW. TC 17S WILL BEGIN TO
TRACK ALONG THE NORTHWESTERN PERIPHERY OF A LOW TO MID-LEVEL RIDGE
THAT IS BEGINNING TO RE-ORIENT AND BUILD OVER WESTERN AUSTRALIA AS A
MID-LATITUDE SHORTWAVE TROUGH TRACKS EASTWARD ACROSS AUSTRALIA. THE
INCREASED OUTFLOW AND FAVORABLE SEA SURFACE TEMPERATURES WILL
PROVIDE SOME INTENSIFICATION THROUGH TAU 36, BUT AS THE SYSTEM
TRACKS INTO STRONGER VERTICAL WIND SHEAR AND COLDER SST, IT WILL
WEAKEN BEYOND TAU 36. THE AVAILABLE DYNAMIC GUIDANCE IS IN GOOD
AGREEMENT WITH THIS TRACK. MAXIMUM SIGNIFICANT WAVE HEIGHT AT
030000Z IS 12 FEET. NEXT WARNINGS AT 031500Z AND 040300Z.//
=========================================================================
WTXS31 PGTW 20090303 15:00z
1. TROPICAL CYCLONE 17S (GABRIELLE) WARNING NR 004
   01 ACTIVE TROPICAL CYCLONE IN SOUTHIO
   MAX SUSTAINED WINDS BASED ON ONE-MINUTE AVERAGE
    ---
   WARNING POSITION:
   031200Z --- NEAR 15.0S 107.7E
     MOVEMENT PAST SIX HOURS - 190 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: 15.0S 107.7E
    ---
   FORECASTS:
   12 HRS, VALID AT:
   040000Z --- 15.7S 106.4E
   MAX SUSTAINED WINDS - 040 KT, GUSTS 050 KT
   WIND RADII VALID OVER OPEN WATER ONLY
   RADIUS OF 034 KT WINDS - 050 NM NORTHEAST QUADRANT
                            055 NM SOUTHEAST QUADRANT
                            055 NM SOUTHWEST QUADRANT
                            050 NM NORTHWEST QUADRANT
   VECTOR TO 24 HR POSIT: 245 DEG/ 09 KTS
    ---
   24 HRS, VALID AT:
   041200Z --- 16.5S 104.7E
   MAX SUSTAINED WINDS - 045 KT, GUSTS 055 KT
   WIND RADII VALID OVER OPEN WATER ONLY
   RADIUS OF 034 KT WINDS - 055 NM NORTHEAST QUADRANT
                            065 NM SOUTHEAST QUADRANT
                            065 NM SOUTHWEST QUADRANT
                            055 NM NORTHWEST QUADRANT
   VECTOR TO 36 HR POSIT: 245 DEG/ 11 KTS
    ---
   36 HRS, VALID AT:
   050000Z --- 17.4S 102.5E
   MAX SUSTAINED WINDS - 040 KT, GUSTS 050 KT
   WIND RADII VALID OVER OPEN WATER ONLY
   RADIUS OF 034 KT WINDS - 050 NM NORTHEAST QUADRANT
                            055 NM SOUTHEAST QUADRANT
                            055 NM SOUTHWEST QUADRANT
                            050 NM NORTHWEST QUADRANT
   VECTOR TO 48 HR POSIT: 235 DEG/ 15 KTS
    ---
   EXTENDED OUTLOOK:
   48 HRS, VALID AT:
   051200Z --- 19.1S 99.9E
   MAX SUSTAINED WINDS - 035 KT, GUSTS 045 KT
   WIND RADII VALID OVER OPEN WATER ONLY
    ---
REMARKS:
031500Z POSITION NEAR 15.2S 107.4E.
TROPICAL CYCLONE (TC) 17S (GABRIELLE), LOCATED APPROXIMATELY 660 NM
EAST-SOUTHEAST OF THE COCOS ISLANDS HAS TRACKED SOUTHWARD AT 05
KNOTS OVER THE PAST 06 HOURS. RECENT ANIMATED INFRARED SATELLITE
IMAGERY SHOWS THAT THE LOW LEVEL CIRCULATION CENTER HAS MOVED BACK
UNDER THE DEEPEST AND MOST PERSISTENT CENTRAL CONVECTION, INCREASING
DVORAK SATELLITE INTENSITY ESTIMATES TO AROUND 35 KNOTS FROM PGTW,
KNES, AND APRF. VERTICAL WIND SHEAR WILL CONTINUE TO EASE OVER THE
NEXT DAY AS THE TC APPROACHES THE SUBTROPICAL RIDGE AXIS TO THE
SOUTH, ALLOWING FOR MODEST INTENSIFICATION. THE LACK OF STRONG
OUTFLOW ALOFT AND LOW OCEAN HEAT CONTENT FURTHER SUPPORTS MINIMAL
INTENSIFICATION OVER THE NEXT 24 HOURS. BEYOND 24 HOURS SEA SURFACE
TEMPERATURES WILL DROP BELOW SUSTAINABLE LEVELS, VERTICAL WIND SHEAR
WILL AGAIN INCREASE, AND THE ATMOSPHERE WILL BECOME LESS MOIST.
COMBINED, ALL THESE CONDITIONS WILL PROMOTE WEAKENING, AND BY TAU
48, TC 17S WILL REMAIN A MINIMAL TC. MAXIMUM SIGNIFICANT WAVE HEIGHT
AT 031200Z IS 13 FEET. NEXT WARNINGS AT 040300Z AND 041500Z.
=========================================================================
WTXS31 PGTW 20090304 03:00z
MSGID/GENADMIN/NAVMARFCSTCEN PEARL HARBOR HI/JTWC//
SUBJ/TROPICAL CYCLONE 17S (GABRIELLE) WARNING NR 005//
RMKS/
1. TROPICAL CYCLONE 17S (GABRIELLE) WARNING NR 005
   01 ACTIVE TROPICAL CYCLONE IN SOUTHIO
   MAX SUSTAINED WINDS BASED ON ONE-MINUTE AVERAGE
    ---
   WARNING POSITION:
   040000Z --- NEAR 14.7S 106.0E
     MOVEMENT PAST SIX HOURS - 290 DEGREES AT 09 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: 14.7S 106.0E
    ---
   FORECASTS:
   12 HRS, VALID AT:
   041200Z --- 15.2S 103.4E
   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 24 HR POSIT: 245 DEG/ 16 KTS
    ---
   24 HRS, VALID AT:
   050000Z --- 16.5S 100.3E
   MAX SUSTAINED WINDS - 025 KT, GUSTS 035 KT
   WIND RADII VALID OVER OPEN WATER ONLY
   DISSIPATED AS A SIGNIFICANT TROPICAL CYCLONE OVER WATER
    ---
REMARKS:
040300Z POSITION NEAR 14.8S 105.4E.
TROPICAL CYCLONE (TC) 17S (GABRIELLE), LOCATED APPROXIMATELY 550 NM
EAST-SOUTHEAST OF THE COCOS ISLANDS, HAS TRACKED WEST-NORTHWESTWARD
AT 09 KNOTS OVER THE PAST 06 HOURS. RECENT ANIMATED INFRARED
SATELLITE IMAGERY SHOWS THAT THE LOW LEVEL CIRCULATION CENTER (LLCC)
IS SHEARED FROM THE DEEPEST CONVECTION. RECENT POLAR ORBITING
SATELLITE DATA INDICATES THAT THE LLCC HAS BROADENED WITH CONTINUED
WEAK CONVECTIVE BANDING WRAPPING IN FROM THE SOUTHERN QUADRANTS. THE
SYSTEM HAS TURNED NORTH OF WEST UNDER THE INFLUENCE OF AN EXTENSION
OF LOW LEVEL RIDGING TO THE SOUTH. MARGINAL SEA SURFACE TEMPERATURES
AND LOW TO MODERATE VERTICAL WINDSHEAR HAVE PREVENTED THE
INTENSIFICATION PREVIOUSLY FORECAST. TC 17S IS EXPECTED TO CONTINUE
TO TRACK WEST TO WEST-SOUTHWESTWARD UNDER THE INFLUENCE OF THE
RIDGING TO THE SOUTH AND CONTINUE TO WEAKEN.
MAXIMUM SIGNIFICANT WAVE HEIGHT AT 040000Z IS 13 FEET.
NEXT WARNINGS AT 041500Z.
=========================================================================
WTXS31 PGTW 20090304 09:00z
1. TROPICAL CYCLONE 17S (GABRIELLE) WARNING NR 006
   01 ACTIVE TROPICAL CYCLONE IN SOUTHIO
   MAX SUSTAINED WINDS BASED ON ONE-MINUTE AVERAGE
    ---
   WARNING POSITION:
   040600Z --- NEAR 16.0S 104.9E
     MOVEMENT PAST SIX HOURS - 215 DEGREES AT 15 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: 16.0S 104.9E
    ---
   FORECASTS:
   12 HRS, VALID AT:
   041800Z --- 17.1S 102.6E
   MAX SUSTAINED WINDS - 025 KT, GUSTS 035 KT
   WIND RADII VALID OVER OPEN WATER ONLY
   DISSIPATED AS A SIGNIFICANT TROPICAL CYCLONE OVER WATER
   VECTOR TO 24 HR POSIT: 245 DEG/ 16 KTS
    ---
   24 HRS, VALID AT:
   050600Z --- 18.3S 99.5E
   MAX SUSTAINED WINDS - 020 KT, GUSTS 030 KT
   WIND RADII VALID OVER OPEN WATER ONLY
   DISSIPATED AS A SIGNIFICANT TROPICAL CYCLONE OVER WATER
    ---
REMARKS:
040900Z POSITION NEAR 16.3S 104.3E.
TROPICAL CYCLONE (TC) 17S (GABRIELLE), LOCATED APPROXIMATELY 520 NM
EAST-SOUTHEAST OF THE COCOS ISLANDS, HAS TRACKED SOUTH-SOUTHWESTWARD
AT 15 KNOTS OVER THE PAST 06 HOURS. RECENT ANIMATED MULTISPECTRAL
IMAGERY SHOWS A BROADENING, PARTIALLY EXPOSED LOW LEVEL CIRCULATION
CENTER EQUATORWARD OF MODERATELY SHEARED AND WEAKENED CONVECTION.
THE TC IS TRACKING GENERALLY SOUTHWESTWARD ALONG THE NORTHWESTERN
PERIPHERY OF A STRENGTHENING LOW TO MID-LEVEL SUBTROPICAL RIDGE
TOWARDS COOL WATER AND INCREASED VERTICAL WIND SHEAR. AS SUCH, THE
TC IS FORECAST TO CONTINUE TO WEAKEN WELL BELOW THE WARNING
THRESHOLD OF 35 KNOTS. 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 040600Z IS 13 FEET.

Tropical cyclone tracks developed by Michael Bath using operational warnings and advisories.


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Document: tropical_cyclone_gabrielle_jtwc_advisories.htm Updated: 2 May 2017