WTXS21 PGTW 20100309 14:00z
MSGID/GENADMIN/NAVMARFCSTCEN PEARL HARBOR HI/JTWC//
SUBJ/TROPICAL CYCLONE FORMATION ALERT//
RMKS/
1. FORMATION OF A SIGNIFICANT TROPICAL CYCLONE IS POSSIBLE WITHIN
A 105 NM RADIUS OF 20.1S 50.8E WITHIN THE NEXT 12 TO 24 HOURS.
AVAILABLE DATA DOES NOT JUSTIFY ISSUANCE OF NUMBERED TROPICAL CY-
CLONE WARNINGS AT THIS TIME. WINDS IN THE AREA ARE ESTIMATED TO
BE 25 TO 30 KNOTS. METSAT IMAGERY AT 091130Z INDICATES THAT A
CIRCULATION CENTER IS LOCATED NEAR 20.1S 50.8E. THE SYSTEM IS
MOVING SOUTH-SOUTHEASTWARD AT 04 KNOTS.
2. REMARKS: THE AREA OF CONVECTION PREVIOUSLY LOCATED NEAR 19.9S
50.2E, IS NOW LOCATED NEAR 20.1S 50.8E, APPROXIMATELY 225 NM EAST-
SOUTHEAST OF ANTANANARIVO. RECENT ANIMATED MULTISPECTRAL SATELLITE
IMAGERY SHOWS IMPROVED ORGANIZATION WITH CURVED CONVECTIVE BANDING
AROUND A LOW LEVEL CIRCULATION CENTER (LLCC). IN ADDITION, A 090532Z
ASCAT PASS INDICATES A TIGHTLY WRAPPED LLCC WITH 30 KNOT WINDS. UPPER
LEVEL ANALYSIS SHOWS THE SYSTEM IS LOCATED BENEATH AN ANTICYCLONE
SUPPORTING LOW VERTICAL WIND SHEAR AND FAVORABLE RADIAL OUTFLOW IN
THE NORTHERN SEMI-CIRCLE. A MID-LATITUDE UPPER LEVEL TROUGH TO THE
SOUTHWEST IS SUPPORTING AN EASTWARD OUTFLOW CHANNEL. MAXIMUM SUS-
TAINED SURFACE WINDS ARE ESTIMATED AT 25 TO 30 KNOTS. MINIMUM SEA
LEVEL PRESSURE IS ESTIMATED TO BE NEAR 1000 MB. DUE TO HIGH SEA
SURFACE TEMPERATURES/OCEAN HEAT CONTENT AND IMPROVED CONVECTIVE
BANDING, 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
101400Z.//
=========================================================================
WTXS31 PGTW 20100310 03:00z
MSGID/GENADMIN/NAVMARFCSTCEN PEARL HARBOR HI/JTWC//
SUBJ/TROPICAL CYCLONE 18S (HUBERT) WARNING NR 002//
RMKS/
1. TROPICAL CYCLONE 18S (EIGHTEEN) 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: 
100000Z --- NEAR 20.3S 50.1E 
MOVEMENT PAST SIX HOURS - 270 DEGREES AT 02 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: 20.3S 50.1E 
--- 
FORECASTS: 
12 HRS, VALID AT: 
101200Z --- 20.3S 49.6E 
MAX SUSTAINED WINDS - 040 KT, GUSTS 050 KT 
WIND RADII VALID OVER OPEN WATER ONLY 
RADIUS OF 034 KT WINDS - 020 NM NORTHEAST QUADRANT 
020 NM SOUTHEAST QUADRANT 
020 NM SOUTHWEST QUADRANT 
020 NM NORTHWEST QUADRANT 
VECTOR TO 24 HR POSIT: 290 DEG/ 03 KTS 
--- 
24 HRS, VALID AT: 
110000Z --- 20.1S 49.0E 
MAX SUSTAINED WINDS - 035 KT, GUSTS 045 KT 
WIND RADII VALID OVER OPEN WATER ONLY 
DISSIPATING AS A SIGNIFICANT TROPICAL CYCLONE OVER WATER 
VECTOR TO 36 HR POSIT: 300 DEG/ 04 KTS 
--- 
36 HRS, VALID AT: 
111200Z --- 19.7S 48.3E 
MAX SUSTAINED WINDS - 030 KT, GUSTS 040 KT 
WIND RADII VALID OVER OPEN WATER ONLY 
DISSIPATING AS A SIGNIFICANT TROPICAL CYCLONE OVER LAND 
VECTOR TO 48 HR POSIT: 275 DEG/ 06 KTS 
--- 
EXTENDED OUTLOOK: 
48 HRS, VALID AT: 
120000Z --- 19.6S 47.0E 
MAX SUSTAINED WINDS - 025 KT, GUSTS 035 KT 
WIND RADII VALID OVER OPEN WATER ONLY 
DISSIPATED AS A SIGNIFICANT TROPICAL CYCLONE OVER LAND 
--- 
REMARKS: 
100300Z POSITION NEAR 20.3S 50.0E. 

THIS WARNING SUPERSEDES AND CANCELS REF A, NAVMARFCSTCEN 091400Z 
MAR 10 TROPICAL CYCLONE FORMATION ALERT (WTXS21 PGTW 091400 ) 
MAXIMUM SIGNIFICANT WAVE HEIGHT AT 100000Z IS 8 FEET. 
NEXT WARNINGS AT 101500Z AND 110300Z. 
=========================================================================
WTXS31 PGTW 20100310 15:00z
MSGID/GENADMIN/NAVMARFCSTCEN PEARL HARBOR HI/JTWC//
SUBJ/TROPICAL CYCLONE 18S (HUBERT) WARNING NR 002//
RMKS/
1. TROPICAL CYCLONE 18S (HUBERT) 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:
   101200Z --- NEAR 20.9S 49.0E
     MOVEMENT PAST SIX HOURS - 245 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
   DISSIPATING AS A SIGNIFICANT TROPICAL CYCLONE OVER WATER
   REPEAT POSIT: 20.9S 49.0E
    ---
   FORECASTS:
   12 HRS, VALID AT:
   110000Z --- 21.0S 48.1E
   MAX SUSTAINED WINDS - 030 KT, GUSTS 040 KT
   WIND RADII VALID OVER OPEN WATER ONLY
   DISSIPATED AS A SIGNIFICANT TROPICAL CYCLONE OVER LAND
   VECTOR TO 24 HR POSIT: 265 DEG/ 04 KTS
    ---
   24 HRS, VALID AT:
   111200Z --- 21.1S 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:
101500Z POSITION NEAR 20.9S 48.8E.
TROPICAL CYCLONE (TC) 18S (HUBERT), LOCATED APPROXIMATELY 160 NM
SOUTHEAST OF ANTANANARIVO, MADAGASCAR, HAS TRACKED WEST-
SOUTHWESTWARD AT 05 KNOTS OVER THE PAST SIX HOURS. ANIMATED
MULTISPECTRAL SATELLITE IMAGERY SHOWS LOSS OF CENTRAL CONVECTION AND
DISORGANIZATION AS TC 18S MOVES CLOSER TO LAND. INITIAL POSITION IS
BASED ON ANIMATION AND INITIAL INTENSITY IS BASED ON PGTW AND KNES
DVORAK INTENSITY ESTIMATES OF 35 KNOTS. THE UPPER LEVEL POLEWARD
OUTFLOW CHANNEL HAS WEAKENED AND THERE CONTINUES TO BE RADIAL
OUTFLOW IN THE NORTHERN SEMI-CIRCLE. A SUBTROPICAL RIDGE TO THE
SOUTH IS CURRENTLY STEERING TC 18S OVER LAND AND WILL CONTINUE
THROUGHOUT THE FORECAST PERIOD. INTENSITIES WILL BEGIN TO DECREASE
WITHIN THE NEXT 12 HOURS AND HUBERT WILL DISSIPATE BELOW TROPICAL
CYCLONE STRENGTH OVER LAND. NUMERICAL MODEL GUIDANCE IS IN GOOD
AGREEMENT WITH THIS FORECAST EXCEPT FOR GFDN THAT TRACKS THE SYSTEM
SLOWLY NORTHWARD. 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 101200Z IS 8 FEET.//

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

Document: tropical_cyclone_hubert_jtwc_advisories.htm Updated: 17 June 2020 [Australian Severe Weather index] [Copyright Notice] [Email Contacts] [Search This Site] [Privacy Policy]