Tropical Cyclones [Index]

Tropical Cyclone 199803 [Australian Region][South Indian Ocean][South Pacific Ocean][Southern Hemisphere][Summaries and Track Data]

WTPS21 PGTW 971026 02:00z
SUBJ/TROPICAL CYCLONE FORMATION ALERT 260151Z OCT 97//
RMKS/
1. IMMEDIATE DELIVERY REQ TO AMEMBASSY SUVA
2. AMEMBASSY SUVA REQ PASS TO USAID OFDA ADVISOR
3. FORMATION OF A SIGNIFICANT TROPICAL CYCLONE IS
POSSIBLE WITHIN 180 NM EITHER SIDE OF A LINE FROM 11.2S4
173.6E7 TO 20.0S2 171.3E2 WITHIN THE NEXT 06 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 20 TO 30 KNOTS. METSAT IMAGERY AT
252330Z5 INDICATES THAT A CIRCULATION CENTER IS LOCATED
NEAR 13.4S8 173.1E2. THE SYSTEM IS MOVING SOUTHWESTWARD
AT 06 KNOTS.
4. REMARKS:
THE CIRCULATION AND AREA OF PERSISTENT CONVECTION LOCATED
TO THE NORTHWEST OF THE FIJI ISLANDS, APPROXIMATELY 160
NM WEST OF ROTUMA (WMO 91650), HAS SHOWN INCREASED
CONVECTIVE ORGANIZATION IN THE PAST 6 TO 12 HOURS. NEW
CONVECTION HAS FORMED OVER THE SYSTEMS CENTER AND UPPER-
LEVEL OUTFLOW HAS IMPROVED. RECENT SHIP REPORTS INDICATE
WINDS SOUTH OF THE CIRCULATION ARE IN EXCESS OF 25 KNOTS.
MINIMUM SURFACE PRESSURE IS ESTIMATED TO BE 1004 MB. THE
POTENTIAL FOR SIGNIFICANT TROPICAL CYCLONE DEVELOPMENT IS
GOOD FOR THE NEXT 24 HOURS.
5. THIS ALERT VALID UNTIL 270200Z1.//
=========================================================================
WTPS31 PGTW 971026 15:00z CORRECTED
IMMEDIATE DELIVERY REQ TO AMEMBASSY SUVA
AMEMBASSY SUVA REQ PASS TO USAID OFDA ADVISOR
THIS WARNING SUPERSEDES AND CANCELS NAVPACMETOCCEN WEST
GU 260151Z OCT 97
TROPICAL CYCLONE FORMATION ALERT (WTPS21 PGTW 260200)
1. TROPICAL CYCLONE 03P WARNING NR 01
   01 ACTIVE TROPICAL CYCLONE IN SOUTHERN HEMISPHERE
   MAX SUSTAINED WINDS BASED ON ONE-MINUTE AVERAGE
    ---
   WARNING POSITION:
   261200Z1 --- 12.8S1 174.5E7
     MOVEMENT PAST SIX HOURS - 225 DEGREES AT 03 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
   REPEAT POSIT: 12.8S1 174.5E7
    ---
   FORECASTS:
   12 HRS, VALID AT:
   270000Z9 --- 13.4S8 174.0E2
   MAX SUSTAINED WINDS - 040 KT, GUSTS 050 KT
   RADIUS OF 035 KT WINDS - 035 NM
   VECTOR TO 24 HR POSIT: 220 DEG/ 05 KTS
    ---
   24 HRS, VALID AT:
   271200Z2 --- 14.1S6 173.4E5
   MAX SUSTAINED WINDS - 045 KT, GUSTS 055 KT
   RADIUS OF 035 KT WINDS - 040 NM
   VECTOR TO 36 HR POSIT: 210 DEG/ 06 KTS
    ---
   36 HRS, VALID AT:
   280000Z0 --- 15.2S8 172.7E7
   MAX SUSTAINED WINDS - 050 KT, GUSTS 065 KT
   RADIUS OF 035 KT WINDS - 045 NM
   VECTOR TO 48 HR POSIT: 190 DEG/ 07 KTS
    ---
   EXTENDED OUTLOOK:
   48 HRS, VALID AT:
   281200Z3 --- 16.6S3 172.5E5
   MAX SUSTAINED WINDS - 055 KT, GUSTS 070 KT
   RADIUS OF 050 KT WINDS - 010 NM
   RADIUS OF 035 KT WINDS - 050 NM EAST SEMICIRCLE
                            040 NM ELSEWHERE
    ---
REMARKS:
261500Z4 POSITION 12.9S2  174.4E6
DURING THE PAST 12 HOURS, THE TROPICAL DISTURBANCE
LOCATED APPROXIMATELY 300 NM NORTHWEST OF FIJI HAS
STRENGTHENED INTO TROPICAL CYCLONE 03P WHILE TRACKING
SLOWLY SOUTHWESTWARD.  DURING THE PAST 5 HOURS, A CENTRAL
DENSE OVERCAST (CDO) FEATURE HAS BECOME APPARENT IN
SATELLITE IMAGERY.  HOWEVER, THE CONVECTION ASSOCIATED
WITH TC 03P HAS SHOWN CONSIDERABLE DIURNAL FLUCTUATION
WITH AN INCREASE AT NIGHT AND A DECREASE DURING THE DAY.
ALSO, MODERATE TO STRONG NORTHEASTERLY UPPER-LEVEL WINDS
ARE CREATING SIGNIFICANT VERTICAL WIND SHEAR ON THIS
SYSTEM.  AS A RESULT, WE HAVE HELD OUR INITIAL AND
FORECAST INTENSITIES DOWN SLIGHTLY DESPITE A 261130Z3
DVORAK SATELLITE INTENSITY ESTIMATE OF T3.0 (45 KNOTS).
UNTIL THE CONVECTIVE PATTERN ASSOCIATED WITH TC 03P SHOWS
SIGNS OF MAINTAINING A PERSISTENT ORGANIZED PATTERN
AROUND THE CIRCULATION CENTER, THIS SYSTEM WILL DEVELOP
VERY SLOWLY BEFORE REACHING THE SUBTROPICAL RIDGE AXIS
LOCATED ALONG 16S7 LATITUDE.  THERE IS CONSIDERABLE
DIVERGENCE AMONG OUR OBJECTIVE FORECAST AIDS, BUT WE HAVE
FOLLOWED THE TWO BETA ADVECTION MODELS (MBAM AND FBAM)
FOR GENERAL TRACK DIRECTION AND FOLLOWED OUR
CLIMATOLOGICAL MODEL FOR TRACK SPEED. ONCE TC 02P REACHES
THE SUBTROPICAL RIDGE AXIS, AN APPROACHING SHORTWAVE
TROUGH FROM THE WEST AS SEEN IN WATER VAPOR IMAGERY AND
SYNOPTIC DATA SHOULD INCREASE THE VERTICAL SHEAR ON THIS
SYSTEM AND GRADUALLY INDUCE RECURVATURE TO THE SOUTHEAST.
MAXIMUM SIGNIFICANT WAVE HEIGHT AT 261200Z1 IS 08 FEET.
NEXT WARNINGS AT 270300Z2 (DTG 270151Z6) AND 271500Z5
(DTG 271351Z9).  THIS WARNING SUPERSEDES AND CANCELS
NAVPACMETOCCEN WEST GU 260151Z OCT 97 TROPICAL CYCLONE
FORMATION ALERT (WTPS21 PGTW 260200).
JUSTIFICATION FOR CORRECTION: REFERENCING DTG FOR
TROPICAL CYCLONE FORMATION ALERT.//
=========================================================================
WTPS31 PGTW 971027 03:00z
IMMEDIATE DELIVERY REQ TO AMEMBASSY SUVA
AMEMBASSY SUVA REQ PASS TO USAID OFDA ADVISOR
1. TROPICAL CYCLONE 03P WARNING NR 002
   01 ACTIVE TROPICAL CYCLONE IN SOUTHERN HEMISPHERE
   MAX SUSTAINED WINDS BASED ON ONE-MINUTE AVERAGE
    ---
   WARNING POSITION:
   270000Z9 --- 13.5S9 173.5E6
     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
   REPEAT POSIT: 13.5S9 173.5E6
    ---
   FORECASTS:
   12 HRS, VALID AT:
   271200Z2 --- 14.1S6 172.8E8
   MAX SUSTAINED WINDS - 035 KT, GUSTS 045 KT
   VECTOR TO 24 HR POSIT: 220 DEG/ 04 KTS
    ---
   24 HRS, VALID AT:
   280000Z0 --- 14.7S2 172.3E3
   MAX SUSTAINED WINDS - 030 KT, GUSTS 040 KT
   DISSIPATING AS A SIGNIFICANT TROPICAL CYCLONE OVER
WATER
   VECTOR TO 36 HR POSIT: 210 DEG/ 04 KTS
    ---
   36 HRS, VALID AT:
   281200Z3 --- 15.4S0 171.9E8
   MAX SUSTAINED WINDS - 030 KT, GUSTS 040 KT
   DISSIPATING AS A SIGNIFICANT TROPICAL CYCLONE OVER
WATER
   VECTOR TO 48 HR POSIT: 195 DEG/ 04 KTS
    ---
   EXTENDED OUTLOOK:
   48 HRS, VALID AT:
   290000Z1 --- 16.1S8 171.7E6
   MAX SUSTAINED WINDS - 030 KT, GUSTS 040 KT
   DISSIPATED AS A SIGNIFICANT TROPICAL CYCLONE OVER
WATER
    ---
REMARKS:
270300Z2 POSITION 13.7S1  173.3E4
TROPICAL CYCLONE 03P CONTINUES TO MOVE IN A SOUTHWEST
DIRECTION AT 5 KNOTS. IN THE PAST 12 HOURS THIS SYSTEM
REACHED PEAK INTENSITY AND IS NOW BEGINNING TO WEAKEN
SLOWLY. CURRENT VISIBLE SATELLITE IMAGERY SHOWS THE
CENTRAL CONVECTION HAS BECOME DISORGANIZED. THE
PREVIOUSLY EXPOSED LOW-LEVEL CIRCULATION IS NO LONGER
DISTINGUISHABLE FROM THE LOCAL AREA CONVECTION AND IS
MORE DIFFICULT TO POSITION. AS TC 03P CONTINUES ON A
SOUTHWESTWARD TRACK THE SYSTEM IS FORECAST TO ENCOUNTER
INCREASING VERTICAL WIND SHEAR FROM A 500 MB TROUGH
LOCATED TO THE WEST OF THE CIRCULATION. THIS SYSTEM WILL
BEGIN DISSIPATING OVER WATER AFTER THE 36 HOUR FORECAST
POSITION. MAXIMUM SIGNIFICANT WAVE HEIGHT AT 270000Z9 IS
12 FEET. NEXT WARNINGS AT 271500Z5 (DTG 271351Z9) AND
280300Z3 (DTG 280151Z7).//
=========================================================================
WTPS31 PGTW 971027 15:00z
IMMEDIATE DELIVERY REQ TO AMEMBASSY SUVA
AMEMBASSY SUVA REQ PASS TO USAID OFDA ADVISOR
1. TROPICAL CYCLONE 03P WARNING NR 03 RELOCATED
   01 ACTIVE TROPICAL CYCLONE IN SOUTHERN HEMISPHERE
   MAX SUSTAINED WINDS BASED ON ONE-MINUTE AVERAGE
    ---
   WARNING POSITION:
   271200Z2 --- 13.2S6 175.5E8
     MOVEMENT PAST SIX HOURS - 200 DEGREES AT 03 KTS
     POSITION ACCURATE TO WITHIN 060 NM
     POSITION BASED ON CENTER LOCATED BY A COMBINATION OF
     SATELLITE AND SYNOPTIC DATA
   PRESENT WIND DISTRIBUTION:
   MAX SUSTAINED WINDS - 035 KT, GUSTS 045 KT
   REPEAT POSIT: 13.2S6 175.5E8
    ---
   FORECASTS:
   12 HRS, VALID AT:
   280000Z0 --- 14.2S7 175.2E5
   MAX SUSTAINED WINDS - 035 KT, GUSTS 045 KT
   VECTOR TO 24 HR POSIT: 195 DEG/ 05 KTS
    ---
   24 HRS, VALID AT:
   281200Z3 --- 15.2S8 174.9E1
   MAX SUSTAINED WINDS - 030 KT, GUSTS 040 KT
   DISSIPATING AS A SIGNIFICANT TROPICAL CYCLONE OVER
WATER
   VECTOR TO 36 HR POSIT: 175 DEG/ 06 KTS
    ---
   36 HRS, VALID AT:
   290000Z1 --- 16.4S1 175.0E3
   MAX SUSTAINED WINDS - 030 KT, GUSTS 040 KT
   DISSIPATING AS A SIGNIFICANT TROPICAL CYCLONE OVER
WATER
   VECTOR TO 48 HR POSIT: 160 DEG/ 07 KTS
    ---
   EXTENDED OUTLOOK:
   48 HRS, VALID AT:
   291200Z4 --- 17.7S5 175.5E8
   MAX SUSTAINED WINDS - 030 KT, GUSTS 040 KT
   DISSIPATED AS A SIGNIFICANT TROPICAL CYCLONE OVER
WATER
    ---
REMARKS:
271500Z5 POSITION 13.5S9  175.4E7
TROPICAL CYCLONE 03P HAS REDEVELOPED FARTHER TO THE
NORTHEAST AS COMPARED TO OUR LAST WARNING POSITION AT
270000Z9, AND THIS IS THE REASON FOR THE RELOCATION OF
THE SYSTEM.  THE ORIGINAL LOW-LEVEL CIRCULATION CENTER
HAS SHEARED OUT TO THE SOUTHEAST AND WEAKENED WHILE A NEW
CENTER HAS FORMED FARTHER TO THE NORTH, BASED ON 270600Z5
AND 271200Z2 SYNOPTIC DATA.  NEW DEEP CONVECTION HAS
REDEVELOPED NEAR THE SYSTEM CENTER WITH NUMEROUS CLOUD
TOPS AS COLD AS -83C TO -86C NOTED WITHIN 60 NM OF THE
SYNOPTIC POSITION OF THE LOW-LEVEL CENTER.  HOWEVER, TC
03P REMAINS IN A REGION OF STRONG VERTICAL WIND SHEAR AND
GRADUAL WEAKENING OF THIS SYSTEM IS STILL ANTICIPATED
ONCE TC 03P PASSES SOUTH OF 15S6 LATITUDE AND MOVES OVER
MUCH COOLER WATER WHILE ENCOUNTERING EVEN GREATER
VERTICAL WIND SHEAR. MAXIMUM SIGNIFICANT WAVE HEIGHT AT
271200Z2 IS 12 FEET.  NEXT WARNINGS AT 280300Z3 (DTG
280151Z7) AND 281500Z6 (DTG 281351Z0).//
=========================================================================
WTPS31 PGTW 971028 03:00z
IMMEDIATE DELIVERY REQ TO AMEMBASSY SUVA
AMEMBASSY SUVA REQ PASS TO USAID OFDA ADVISOR
1. TROPICAL CYCLONE 03P WARNING NR 004
   01 ACTIVE TROPICAL CYCLONE IN SOUTHERN HEMISPHERE
   MAX SUSTAINED WINDS BASED ON ONE-MINUTE AVERAGE
    ---
   WARNING POSITION:
   280000Z0 --- 14.9S4 176.0E4
     MOVEMENT PAST SIX HOURS - 180 DEGREES AT 06 KTS
     POSITION ACCURATE TO WITHIN 060 NM
     POSITION BASED ON CENTER LOCATED BY SATELLITE
   PRESENT WIND DISTRIBUTION:
   MAX SUSTAINED WINDS - 025 KT, GUSTS 035 KT
   DISSIPATING AS A SIGNIFICANT TROPICAL CYCLONE OVER
WATER
   REPEAT POSIT: 14.9S4 176.0E4
    ---
   FORECASTS:
   12 HRS, VALID AT:
   281200Z3 --- 16.3S0 176.1E5
   MAX SUSTAINED WINDS - 025 KT, GUSTS 035 KT
   DISSIPATED AS A SIGNIFICANT TROPICAL CYCLONE OVER
WATER
    ---
REMARKS:
280300Z3 POSITION 15.2S8  176.0E4
TROPICAL CYCLONE 03P IS MOVING SOUTHWARD AT 06 KNOTS.
ANIMATED VISIBLE AND WATER VAPOR SATELLITE IMAGERY
INDICATE VERY LITTLE CENTRAL CONVECTION AND CONTINUED
VERTICAL SHEAR OVER THE SYSTEM CENTER. ADDITIONALLY,
TROPICAL CYCLONE 03P IS OVER A REGION OF COOLER SEA
SURFACE TEMPERATURES. THEREFORE, THE SYSTEM IS FORECAST
TO DISSIPATE WITHIN 12 HOURS. MAXIMUM SIGNIFICANT WAVE
HEIGHT AT 280000Z IS 08 FEET. REFER TO WWPW30 PGFW FOR
ADDITIONAL SEA HEIGHT INFORMATION. THIS IS THE FINAL
WARNING ON THIS SYSTEM BY THE JOINT TYPHOON WARNING
CENTER (NAVPACMETOCCEN WEST GU). THE SYSTEM WILL BE
CLOSELY MONITORED FOR SIGNS OF REGENERATION.//