Tropical Cyclones [Index]

Tropical Cyclone 200820 [Australian Region][South Indian Ocean][South Pacific Ocean][Southern Hemisphere][Summaries and Track Data]

WTPS21 PGTW 20080229 02:00z
MSGID/GENADMIN/NAVPACMETOCCEN PEARL HARBOR HI//
SUBJ/TROPICAL CYCLONE FORMATION ALERT//
RMKS/
1. FORMATION OF A SIGNIFICANT TROPICAL CYCLONE IS POSSIBLE WITHIN
150 NM EITHER SIDE OF A LINE FROM 18.1S 150.6E TO 23.6S 160.0E
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 290000Z INDICATES THAT A CIRCULATION CENTER IS LOCATED
NEAR 18.9S 151.7E.  THE SYSTEM IS MOVING EAST-SOUTHEASTWARD AT 18
KNOTS.
2. REMARKS: THE AREA OF CONVECTION PREVIOUSLY LOCATED NEAR 17.6S
147.9E, IS NOW LOCATED NEAR 18.9S 151.7E, APPROXIMATELY 365 NM
EAST-SOUTHEAST OF CAIRNS, AUSTRALIA. RECENT ANIMATED MULTISPECTRAL
IMAGERY SHOWS DEEP CONVECTION HAS DEVELOPED IN THE VICINITY
OF THE LOW LEVEL CIRCULATION CENTER (LLCC). CONVECTIVE BANDING HAS
ALSO DEVELOPED IN THE SOUTHEASTERN QUADRANT, AS SEEN ON A 282153Z
SSMIS MICROWAVE IMAGE. RECENT SURFACE OBSERVATIONS ALSO INDICATE
OVER A 4 MB PRESSURE DROP IN 24 HOURS NEAR THE LLCC. UPPER LEVEL
ANALYSIS REVEALS THE DISTURBANCE IS UNDER A 200 MB ANTICYCLONE,
WHICH IS CREATING FAVORABLE OUTFLOW ALOFT. MAXIMUM SUSTAINED
SURFACE WINDS ARE ESTIMATED AT 25 TO 30 KNOTS. MINIMUM SEA LEVEL
PRESSURE IS ESTIMATED TO BE NEAR 1000 MB. THE POTENTIAL FOR THE
DEVELOPMENT OF A SIGNIFICANT TROPICAL CYCLONE WITHIN THE NEXT
24 HOURS IS UPGRADED TO GOOD.
3. THIS ALERT WILL BE REISSUED, UPGRADED TO WARNING OR CANCELLED
BY 010200Z.//
=========================================================================
WTPS31 PGTW 20080229 09:00z
MSGID/GENADMIN/NAVPACMETOCCEN PEARL HARBOR HI//
SUBJ/TROPICAL CYCLONE WARNING//
REF/A/MSGID/MSG/NAVPACMETOCCEN PEARL HARBOR HI 290151ZFEB2008//
AMPN/REF A IS A TROPICAL CYCLONE FORMATION ALERT.//
RMKS/
1. TROPICAL CYCLONE 20P WARNING NR 001
   01 ACTIVE TROPICAL CYCLONE IN SOUTHPAC
   MAX SUSTAINED WINDS BASED ON ONE-MINUTE AVERAGE
    ---
   WARNING POSITION:
   290600Z --- NEAR 21.2S 154.3E
     MOVEMENT PAST SIX HOURS - 130 DEGREES AT 31 KTS
     POSITION ACCURATE TO WITHIN 040 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: 21.2S 154.3E
    ---
   FORECASTS:
   12 HRS, VALID AT:
   291800Z --- 24.1S 158.4E
   MAX SUSTAINED WINDS - 035 KT, GUSTS 045 KT
   WIND RADII VALID OVER OPEN WATER ONLY
   BECOMING EXTRATROPICAL
   VECTOR TO 24 HR POSIT: 125 DEG/ 20 KTS
    ---
   24 HRS, VALID AT:
   010600Z --- 26.4S 162.0E
   MAX SUSTAINED WINDS - 035 KT, GUSTS 045 KT
   WIND RADII VALID OVER OPEN WATER ONLY
   BECOMING EXTRATROPICAL
   VECTOR TO 36 HR POSIT: 120 DEG/ 20 KTS
    ---
   36 HRS, VALID AT:
   011800Z --- 28.4S 165.8E
   MAX SUSTAINED WINDS - 035 KT, GUSTS 045 KT
   WIND RADII VALID OVER OPEN WATER ONLY
   EXTRATROPICAL
    ---
REMARKS:
290900Z POSITION NEAR 21.9S 155.3E.
TROPICAL CYCLONE (TC) 20P (NONAME) LOCATED APPROXIMATELY
385 NM NORTH-NORTHEAST OF BRISBANE, AUSTRALIA, HAS TRACKED
SOUTHEASTWARD AT 31 KNOTS OVER THE PAST 06 HOURS. RECENT
ANIMATED METSAT IMAGERY DEPICTS AN ASYMMETRIC SYSTEM WITH
A WELL-WRAPPED CONVECTIVE BAND ALONG THE SOUTHEASTERN PERI-
PHERY. INITIAL INTENSITY IS BASED ON SATELLITE INTENSITY
ESTIMATES OF 35 KNOTS FROM KNES AND PGTW. THE SYSTEM IS
NOW UNDER THE INFLUENCE OF MODERATE NORTHWESTERLY VERTICAL
WIND SHEAR ASSOCIATED WITH A HIGH AMPLITUDE MID-LATITUDE
TROUGH. THE FAVORABLE DIFFLUENCE ALOFT WILL BE OFFSET BY
THE VERTICAL WIND SHEAR AND KEEP THE SYSTEM AROUND 35 KNOTS
AS IT BEGINS EXTRATROPICAL TRANSITION AT TAU 12. TC 20P
WILL BECOME FULLY EXTRATROPICAL BY TAU 36. THE DYNAMIC AIDS
ARE IN GOOD AGREEMENT WITH THIS FORECAST. THIS WARNING
SUPERSEDES AND CANCELS REF A, NAVPACMETOCCEN 290151ZFEB2008
TROPICAL CYCLONE FORMATION ALERT (WTPS21 PGTW 290200)
MAXIMUM SIGNIFICANT WAVE HEIGHT AT 290600Z IS 13 FEET. NEXT
WARNINGS AT 292100Z AND 010900Z.//
=========================================================================
WTPS31 PGTW 20080229 21:00z
MSGID/GENADMIN/NAVPACMETOCCEN PEARL HARBOR HI//
SUBJ/TROPICAL CYCLONE WARNING//
RMKS/
1. TROPICAL CYCLONE 20P WARNING NR 002
   01 ACTIVE TROPICAL CYCLONE IN SOUTHPAC
   MAX SUSTAINED WINDS BASED ON ONE-MINUTE AVERAGE
    ---
   WARNING POSITION:
   291800Z --- NEAR 25.0S 159.7E
     MOVEMENT PAST SIX HOURS - 130 DEGREES AT 33 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
   BECOMING EXTRATROPICAL
   REPEAT POSIT: 25.0S 159.7E
    ---
   FORECASTS:
   12 HRS, VALID AT:
   010600Z --- 28.1S 165.0E
   MAX SUSTAINED WINDS - 030 KT, GUSTS 040 KT
   WIND RADII VALID OVER OPEN WATER ONLY
   EXTRATROPICAL
   VECTOR TO 24 HR POSIT: 115 DEG/ 26 KTS
    ---
   24 HRS, VALID AT:
   011800Z --- 30.1S 170.6E
   MAX SUSTAINED WINDS - 030 KT, GUSTS 040 KT
   WIND RADII VALID OVER OPEN WATER ONLY
   EXTRATROPICAL
    ---
REMARKS:
292100Z POSITION NEAR 25.8S 161.0E.
TROPICAL CYCLONE (TC) 20P (NONAME) LOCATED APPROXIMATELY
404 NM WEST-SOUTHWEST OF NOUMEA, NEW CALEDONIA, HAS TRACKED
SOUTHEASTWARD AT 33 KNOTS OVER THE PAST 06 HOURS. RECENT
ANIMATED METSAT IMAGERY DEPICTS AN ELONGATED SYSTEM WITH
CONVECTION ALONG THE SOUTHWESTERN AND NORTHEASTERN PERI-
PHERY. INITIAL INTENSITY IS BASED ON SCATTEROMETRY OBSERV-
ATIONS AND SATELLITE INTENSITY ESTIMATES FROM KNES AND
PGTW. THE SYSTEM IS NOW UNDER THE INFLUENCE OF MODERATE
NORTHWESTERLY VERTICAL WIND SHEAR ASSOCIATED WITH A HIGH
AMPLITUDE MID-LATITUDE TROUGH. THE FAVORABLE DIFFLUENCE
ALOFT WILL BE OFFSET BY THE VERTICAL WIND SHEAR THUS LIMI-
TING FURTHER INTENSIFICATION AS IT COMPLETES EXTRATROPICAL
TRANSITION. TC 20P WILL BECOME FULLY EXTRATROPICAL BY TAU
12. THE DYNAMIC AIDS ARE IN GOOD AGREEMENT WITH THIS FORE-
CAST. MAXIMUM SIGNIFICANT WAVE HEIGHT AT 290600Z IS 13 FEET.
THIS IS THE FINAL WARNING ON THIS SYSTEM BY THE JOINT TYP-
HOON WARNING CENTER (NAVPACMETOCCEN).  THE SYSTEM WILL BE
CLOSELY MONITORED FOR SIGNS OF REGENERATION. MAXIMUM SIGN-
IFICANT WAVE HEIGHT AT 291800Z IS 13 FEET.