Tropical Cyclones [Index]

Tropical Cyclone NICHOLAS [Australian Region][South Indian Ocean][South Pacific Ocean][Southern Hemisphere]

WTXS21 PGTW 961211 19:00z
SUBJ/TROPICAL CYCLONE FORMATION ALERT 111851Z DEC 96//
RMKS/
1. FORMATION OF A SIGNIFICANT TROPICAL CYCLONE IS
POSSIBLE WITHIN 090 NM EITHER SIDE OF A LINE FROM 9.4S3
126.7E6 TO 12.3S6 121.8E2 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 15 TO 20 KNOTS. METSAT IMAGERY AND
SYNOPTIC DATA AT 111730Z INDICATE THAT A CIRCULATION
CENTER IS LOCATED NEAR 10.0S1 125.0E8. THE SYSTEM IS
MOVING WEST-SOUTHWESTWARD AT 08 KNOTS.
2. REMARKS:
ANIMATED SATELLITE IMAGERY AS WELL AS SURFACE SYNOPTIC
REPORTS INDICATE A TROPICAL DISTURBANCE TO THE SOUTHEAST
OF TIMOR HAS BECOME SIGNIFICANTLY BETTER ORGANIZED DURING
THE PAST 24 HOURS. SATELLITE WATER VAPOR IMAGERY SHOWS AN
UPPER-LEVEL ANTICYCLONE IS PRESENT OVER THIS SYSTEM.
AVAILABLE DYNAMIC FORECAST GUIDANCE SUPPORTS DEVELOPMENT
OF THIS SYSTEM DURING THE NEXT 24 HOURS. MINIMUM CENTRAL
PRESSURE IS ESTIMATED TO BE 1004 MB. POTENTIAL FOR
SIGNIFICANT TROPICAL CYCLONE DEVELOPMENT WITHIN THE NEXT
24 HOURS IS GOOD.
3. THIS ALERT VALID UNTIL 121900Z3.//
=========================================================================
WTXS21 PGTW 961212 17:30z
SUBJ/TROPICAL CYCLONE FORMATION ALERT 121721Z DEC 96//
REF/A/RMG/NAVPACMETOCCEN WEST GU/121721Z DEC 96//
AMPN/REF IS TROPICAL CYCLONE FORMATION ALERT (WTXS21 PGTW
121730)//
RMKS/
1. FORMATION OF A SIGNIFICANT TROPICAL CYCLONE IS
POSSIBLE WITHIN 090 NM EITHER SIDE OF A LINE FROM 10.4S5
125.5E3 TO 14.0S5 125.5E3 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 15 TO 25 KNOTS. METSAT IMAGERY AND
SYNOPTIC DATA AT 121630Z INDICATE THAT A CIRCULATION
CENTER IS LOCATED NEAR 11.8S0 125.6E4. THE SYSTEM IS
MOVING SOUTH-SOUTHEASTWARD AT 05 KNOTS.
2. REMARKS:
THIS SUPERSEDES REF A. THE TROPICAL DISTURBANCE IN THE
TIMOR SEA CONTINUES TO BECOME BETTER ORGANIZED AS
INDICATED BY ANIMATED INFRARED AND WATER VAPOR SATELLITE
IMAGERY. NEITHER SATELLITE IMAGERY NOR SYNOPTIC DATA,
HOWEVER, CLEARLY INDICATE WHERE THE LOW-LEVEL CIRCULATION
IS LOCATED. CONVECTION APPEARS TO BE DEVELOPING AND
COLLAPSING AT SEVERAL PLACES ALONG THE PERIPHERY OF THE
REGION OF LOW SURFACE PRESSURE. THIS ALERT IS RE-ISSUED
TO ACCOUNT FOR RECENT MOTION. ANIMATED IMAGERY INDICATES
THE CENTER OF THIS SYSTEM WOULD MOVE OUT OF THE PREVIOUS
ALERT AREA WITHIN THE NEXT HOUR OR TWO. THE POTENTIAL FOR
SIGNIFICANT TROPICAL CYCLONE DEVELOPMENT WITHIN THE NEXT
24 HOURS IS GOOD.
3. THIS ALERT VALID UNTIL 131730Z5.//
=========================================================================
WTXS31 PGTW 961213 03:00z
1. TROPICAL CYCLONE 10S WARNING NR 001
   02 ACTIVE TROPICAL CYCLONES IN SOUTHIO
   MAX SUSTAINED WINDS BASED ON ONE-MINUTE AVERAGE
    ---
   WARNING POSITION:
   130000Z4 --- 12.4S7 124.0E7
     MOVEMENT PAST SIX HOURS - 240 DEGREES AT 06 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 - 030 KT, GUSTS 040 KT
   REPEAT POSIT: 12.4S7 124.0E7
    ---
   FORECASTS:
   12 HRS, VALID AT:
   131200Z7 --- 13.0S4 123.0E6
   MAX SUSTAINED WINDS - 035 KT, GUSTS 045 KT
   VECTOR TO 24 HR POSIT: 240 DEG/ 06 KTS
    ---
   24 HRS, VALID AT:
   140000Z5 --- 13.6S0 122.0E5
   MAX SUSTAINED WINDS - 045 KT, GUSTS 055 KT
   RADIUS OF 035 KT WINDS - 120 NM SOUTHEAST SEMICIRCLE
                            090 NM ELSEWHERE
   VECTOR TO 36 HR POSIT: 235 DEG/ 08 KTS
    ---
   36 HRS, VALID AT:
   141200Z8 --- 14.5S0 120.7E0
   MAX SUSTAINED WINDS - 055 KT, GUSTS 070 KT
   RADIUS OF 050 KT WINDS - 030 NM
   RADIUS OF 035 KT WINDS - 125 NM SOUTHEAST SEMICIRCLE
                            095 NM ELSEWHERE
   VECTOR TO 48 HR POSIT: 230 DEG/ 08 KTS
    ---
   EXTENDED OUTLOOK:
   48 HRS, VALID AT:
   150000Z6 --- 15.5S1 119.5E6
   MAX SUSTAINED WINDS - 065 KT, GUSTS 080 KT
   RADIUS OF 050 KT WINDS - 040 NM
   RADIUS OF 035 KT WINDS - 130 NM SOUTHEAST SEMICIRCLE
                            100 NM ELSEWHERE
    ---
REMARKS:
130300Z7 POSITION 12.6S9  123.7E3
TROPICAL CYCLONE 10S HAS FORMED IN THE TIMOR SEA.
SYNOPTIC DATA IN THE TIMOR SEA INDICATES THE PRESENCE OF
A LOW-LEVEL CYCLONIC CIRCULATION WITH AN ESTIMATED
CENTRAL PRESSURE OF 1003 MB. THE OVERALL CONVECTIVE
ORGANIZATION HAS IMPROVED OVER THE PAST 24 HOURS. TC 10S
IS FORECAST TO CONTINUE TRACKING SOUTHWESTWARD AND TO
INTENSIFY AT A CLIMATOLOGICAL RATE (ONE DVORAK T-NUMBER
PER DAY). NEXT WARNINGS AT 131500Z0 (DTG 131353Z6) AND
140300Z8 (DTG 140153Z4). MAXIMUM SIGNIFICANT WAVE HEIGHT
AT 13/0000Z4 IS 12 FEET. REFER TO TROPICAL CYCLONE 09S
(ELVINA) WARNINGS (WTXS32 PGTW) FOR TWELVE-HOURLY
UPDATES.//
=========================================================================
warning 002 not available
=========================================================================
WTXS31 PGTW 961214 03:00z
1. TROPICAL CYCLONE 10S (NICHOLAS) WARNING NR 003
   02 ACTIVE TROPICAL CYCLONES IN SOUTHIO
   MAX SUSTAINED WINDS BASED ON ONE-MINUTE AVERAGE
    ---
   WARNING POSITION:
   140000Z5 --- 14.7S2 123.7E3
     MOVEMENT PAST SIX HOURS - 190 DEGREES AT 06 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 - 045 KT, GUSTS 055 KT
   RADIUS OF 035 KT WINDS - 120 NM EAST SEMICIRCLE
                                   OVER WATER
                            090 NM ELSEWHERE OVER WATER
   REPEAT POSIT: 14.7S2 123.7E3
    ---
   FORECASTS:
   12 HRS, VALID AT:
   141200Z8 --- 15.8S4 123.1E7
   MAX SUSTAINED WINDS - 055 KT, GUSTS 070 KT
   RADIUS OF 050 KT WINDS - 030 NM OVER WATER
   RADIUS OF 035 KT WINDS - 130 NM EAST SEMICIRCLE
                                   OVER WATER
                            100 NM ELSEWHERE OVER WATER
   VECTOR TO 24 HR POSIT: 210 DEG/ 05 KTS
    ---
   24 HRS, VALID AT:
   150000Z6 --- 16.7S4 122.6E1
   MAX SUSTAINED WINDS - 055 KT, GUSTS 070 KT
   RADIUS OF 050 KT WINDS - 030 NM OVER WATER
   RADIUS OF 035 KT WINDS - 130 NM SOUTHEAST SEMICIRCLE
                                   OVER WATER
                            100 NM ELSEWHERE OVER WATER
   VECTOR TO 36 HR POSIT: 215 DEG/ 06 KTS
    ---
   36 HRS, VALID AT:
   151200Z9 --- 17.6S4 121.9E3
   MAX SUSTAINED WINDS - 055 KT, GUSTS 070 KT
   RADIUS OF 050 KT WINDS - 030 NM OVER WATER
   RADIUS OF 035 KT WINDS - 130 NM SOUTHEAST SEMICIRCLE
                                   OVER WATER
                            100 NM ELSEWHERE OVER WATER
   VECTOR TO 48 HR POSIT: 210 DEG/ 07 KTS
    ---
   EXTENDED OUTLOOK:
   48 HRS, VALID AT:
   160000Z7 --- 18.8S7 121.1E5
   MAX SUSTAINED WINDS - 055 KT, GUSTS 070 KT
   RADIUS OF 050 KT WINDS - 030 NM OVER WATER
   RADIUS OF 035 KT WINDS - 130 NM SOUTHEAST SEMICIRCLE
                                   OVER WATER
                            100 NM ELSEWHERE OVER WATER
    ---
REMARKS:
140300Z8 POSITION 15.0S6  123.6E2
TROPICAL CYCLONE 10S IS TRACKING SOUTHWARD AT 06 KNOTS
NEAR THE STATIONS OF BROWSE (WMO 94103) AND ADELE ISLANDS
(WMO 94210). TC 10S IS MOVING SOUTHWARD IN A WEAKENED
PORTION OF THE SUBTROPICAL RIDGE DUE TO THE MIGRATORY
PRESSURE TROUGH MOVING ACROSS CENTRAL AUSTRALIA. AS THIS
TROUGH MOVES TO THE EAST WE EXPECT TC10S TO HEAD IN A
MORE SOUTHWESTERLY DIRECTION ALONG THE NORTHWESTERN
AUSTRALIAN COAST. TC 10S IS EXPECTED TO INTENSIFY
FOR THE NEXT 12 HOURS. BEYOND THE 12-HOUR FORECAST
POSITION FURTHER INTENSIFICATION IS NOT LIKELY DUE TO THE
TROPICAL CYCLONE=S CLOSE PROXIMITY TO THE AUSTRALIAN
COAST. NEXT WARNINGS AT 141500Z1 (DTG 141353Z7) AND
150300Z9 (DTG 150153Z5). MAXIMUM SIGNIFICANT WAVE HEIGHT
AT 140000Z5 IS 15 FEET. REFER TO TROPICAL CYCLONE 09S
WARNINGS (WTXS32 PGTW) FOR TWELVE-HOURLY UPDATES.//
=========================================================================
WTXS31 PGTW 961214 15:00z
1. TROPICAL CYCLONE 10S (NICHOLAS) WARNING NR 004
   02 ACTIVE TROPICAL CYCLONES IN SOUTHIO
   MAX SUSTAINED WINDS BASED ON ONE-MINUTE AVERAGE
    ---
   WARNING POSITION:
   141200Z8 --- 16.2S9 123.8E4
     MOVEMENT PAST SIX HOURS - 180 DEGREES AT 07 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 - 045 KT, GUSTS 055 KT
   RADIUS OF 035 KT WINDS - 105 NM EAST SEMICIRCLE
                                   OVER WATER
                            090 NM ELSEWHERE OVER WATER
   REPEAT POSIT: 16.2S9 123.8E4
    ---
   FORECASTS:
   12 HRS, VALID AT:
   150000Z6 --- 17.5S3 123.5E1
   MAX SUSTAINED WINDS - 045 KT, GUSTS 055 KT
   DISSIPATING AS A SIGNIFICANT TROPICAL CYCLONE OVER
LAND
   RADIUS OF 035 KT WINDS - 110 NM EAST SEMICIRCLE
                                   OVER WATER
                            095 NM ELSEWHERE OVER WATER
   VECTOR TO 24 HR POSIT: 205 DEG/ 06 KTS
    ---
   24 HRS, VALID AT:
   151200Z9 --- 18.6S5 123.0E6
   MAX SUSTAINED WINDS - 040 KT, GUSTS 050 KT
   DISSIPATING AS A SIGNIFICANT TROPICAL CYCLONE OVER
LAND
   RADIUS OF 035 KT WINDS - 110 NM SOUTHEAST SEMICIRCLE
                                   OVER WATER
                            095 NM ELSEWHERE OVER WATER
   VECTOR TO 36 HR POSIT: 205 DEG/ 07 KTS
    ---
   36 HRS, VALID AT:
   160000Z7 --- 19.8S8 122.4E9
   MAX SUSTAINED WINDS - 035 KT, GUSTS 045 KT
   DISSIPATING AS A SIGNIFICANT TROPICAL CYCLONE OVER
LAND
   RADIUS OF 035 KT WINDS - 105 NM SOUTHEAST SEMICIRCLE
                                   OVER WATER
                            095 NM ELSEWHERE OVER WATER
   VECTOR TO 48 HR POSIT: 215 DEG/ 07 KTS
    ---
   EXTENDED OUTLOOK:
   48 HRS, VALID AT:
   161200Z0 --- 21.0S3 121.5E9
   MAX SUSTAINED WINDS - 030 KT, GUSTS 040 KT
   DISSIPATING AS A SIGNIFICANT TROPICAL CYCLONE OVER
LAND
    ---
REMARKS:
141500Z1 POSITION 16.5S2  123.7E3
TROPICAL CYCLONE 10S (NICHOLAS) CONTINUES TRACKING
SOUTHWARD AT 07 KNOTS. SURFACE SYNOPTIC REPORTS AT
140900Z FROM TROUGHTON ISLAND (WMO 94102) AND ADELE
ISLAND (94210) INDICATE THE CENTER OF TC 10S LIES BETWEEN
THESE TWO REPORTING STATIONS AND NEAREST TO ADELE ISLAND.
THE CURRENT WARNING INTENSITY OF 45 KNOTS IS BASED ON A
SATELLITE DERIVED INTENSITY ANALYSIS (DVORAK CURRENT
INTENSITY OF 3.0). CURRENT WIND RADII HAVE BEEN ADJUSTED
USING 140600Z AND 140900Z SURFACE SYNOPTIC REPORTS. TC
10S IS EXPECTED TO MOVE GENERALLY SOUTH-SOUTHWESTWARD FOR
THE DURATION OF THE FORECAST PERIOD IN STEERING FLOW
AHEAD OF A MID-LATITUDE TROUGH APPROACHING FROM THE WEST.
TC 10S IS FORECAST TO BEGIN DISSIPATING SLOWLY OVER LAND
AFTER MAKING LANDFALL DURING THE NEXT 12 HOURS. MAXIMUM
SIGNIFICANT WAVE HEIGHT AT 141200Z IS 16 FEET. REFER TO
TROPICAL CYCLONE  09S WARNINGS (WTXS32 PGTW) FOR TWELVE-
HOURLY UPDATES. NEXT WARNINGS AT 150300Z9 (DTG 150153Z5)
AND 151500Z2 (DTG 151353Z8).//
=========================================================================
WTXS31 PGTW 961215 03:00z
1. TROPICAL CYCLONE 10S (NICHOLAS) WARNING NR 005
   03 ACTIVE TROPICAL CYCLONES IN SOUTHIO
   MAX SUSTAINED WINDS BASED ON ONE-MINUTE AVERAGE
    ---
   WARNING POSITION:
   150000Z6 --- 17.2S0 123.2E8
     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 SYNOPTIC DATA
   PRESENT WIND DISTRIBUTION:
   MAX SUSTAINED WINDS - 035 KT, GUSTS 045 KT
   DISSIPATING AS A SIGNIFICANT TROPICAL CYCLONE OVER
LAND
   REPEAT POSIT: 17.2S0 123.2E8
    ---
   FORECASTS:
   12 HRS, VALID AT:
   151200Z9 --- 18.4S3 122.7E2
   MAX SUSTAINED WINDS - 025 KT, GUSTS 035 KT
   DISSIPATED AS A SIGNIFICANT TROPICAL CYCLONE OVER LAND
    ---
REMARKS:
150300Z9 POSITION 17.5S3  123.1E7
TROPICAL CYCLONE 10S (NICHOLAS) IS DISSIPATING AS A
SIGNIFICANT TROPICAL CYCLONE OVER WESTERN AUSTRALIA.
INTERACTION WITH THE AUSTRALIAN CONTINENT AS WELL AS
STRONG VERTICAL WIND SHEAR HAVE ACTED TO DISSIPATE TC
10S. 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. REFER TO TROPICAL CYCLONE 09S WARNINGS
(WTXS32 PGTW) FOR TWELVE-HOURLY UPDATES. REFER TO
TROPICAL CYCLONE 11S WARNINGS (WTXS33 PGTW) FOR TWELVE-
HOURLY UPDATES.//