WTXS21 PGTW 20100202 02:30z
MSGID/GENADMIN/NAVMARFCSTCEN PEARL HARBOR HI/JTWC//
SUBJ/TROPICAL CYCLONE FORMATION ALERT//
RMKS/
1. FORMATION OF A SIGNIFICANT TROPICAL CYCLONE IS POSSIBLE WITHIN
A 250 NM RADIUS OF 20.5S 42.7E 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 
25 TO 30 KNOTS. METSAT IMAGERY AT 022330Z INDICATES THAT A
CIRCULATION CENTER IS LOCATED NEAR 20.7S 42.8E. THE SYSTEM IS
MOVING SOUTHWARD AT 04 KNOTS.
2. REMARKS:
THE AREA OF CONVECTION PREVIOUSLY LOCATED NEAR 19.7S 42.7E, IS NOW 
LOCATED NEAR 20.7S 42.8E, APPROXIMATELY 260 NM WEST-SOUTHWEST OF 
ANTANANARIVO, MADAGASCAR. RECENT ANIMATED INFRARED SATELLITE IMAGERY 
AND A 012228Z AMSR-E MICROWAVE IMAGE SHOW DEEP CONVECTIVE BANDING 
WRAPPING INTO A RAPIDLY DEVELOPING LOW LEVEL CIRCULATION CENTER 
(LLCC). UPPER LEVEL ANALYSIS INDICATES THE SYSTEM IS LOCATED IN AN 
AREA OF LOW VERTICAL WIND SHEAR BENEATH AN ANTICYCLONE ALOFT THAT IS 
PROVIDING SUBSTANTIAL RADIAL OUTFLOW. ENVIRONMENTAL FACTORS ARE 
INCREASINGLY FAVORABLE FOR DEVELOPMENT, HOWEVER THE SYSTEM FORMATION 
COULD BE HINDERED IF IT BEGINS TO TRACK EASTWARD OVER MADAGASCAR. 
MAXIMUM SUSTAINED SURFACE WINDS ARE ESTIMATED AT 25 TO 30 KNOTS 
BASED ON DVORAK ESTIMATES FROM PGTW AND FMEE. MINIMUM SEA LEVEL 
PRESSURE IS ESTIMATED TO BE NEAR 1000MB. DUE TO INCREASED CONVECTIVE 
CONSOLIDATION AND MULTIPLE BANDS EVIDENT IN MICROWAVE IMAGERY, THE 
POTENTIAL FOR 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 
030230Z.//
=========================================================================
WTXS31 PGTW 20100202 09:00z
MSGID/GENADMIN/NAVMARFCSTCEN PEARL HARBOR HI/JTWC//
SUBJ/TROPICAL CYCLONE 13S (FAMI) WARNING NR 001//
RMKS/
1. TROPICAL CYCLONE 13S (FAMI) 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:
   020600Z --- NEAR 21.0S 43.5E
     MOVEMENT PAST SIX HOURS - 120 DEGREES AT 08 KTS
     POSITION ACCURATE TO WITHIN 060 NM
     POSITION BASED ON CENTER LOCATED BY SATELLITE
   PRESENT WIND DISTRIBUTION:
   MAX SUSTAINED WINDS - 040 KT, GUSTS 050 KT
   WIND RADII VALID OVER OPEN WATER ONLY
   RADIUS OF 034 KT WINDS - 035 NM NORTHEAST QUADRANT
                            035 NM SOUTHEAST QUADRANT
                            035 NM SOUTHWEST QUADRANT
                            035 NM NORTHWEST QUADRANT
   REPEAT POSIT: 21.0S 43.5E
    ---
   FORECASTS:
   12 HRS, VALID AT:
   021800Z --- 21.6S 44.6E
   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 24 HR POSIT: 110 DEG/ 07 KTS
    ---
   24 HRS, VALID AT:
   030600Z --- 22.1S 46.1E
   MAX SUSTAINED WINDS - 025 KT, GUSTS 035 KT
   WIND RADII VALID OVER OPEN WATER ONLY
   DISSIPATING AS A SIGNIFICANT TROPICAL CYCLONE OVER LAND
   VECTOR TO 36 HR POSIT: 110 DEG/ 07 KTS
    ---
   36 HRS, VALID AT:
   031800Z --- 22.6S 47.5E
   MAX SUSTAINED WINDS - 025 KT, GUSTS 035 KT
   WIND RADII VALID OVER OPEN WATER ONLY
   DISSIPATING AS A SIGNIFICANT TROPICAL CYCLONE OVER LAND
   VECTOR TO 48 HR POSIT: 110 DEG/ 10 KTS
    ---
   EXTENDED OUTLOOK:
   48 HRS, VALID AT:
   040600Z --- 23.3S 49.6E
   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 72 HR POSIT: 120 DEG/ 12 KTS
    ---
   72 HRS, VALID AT:
   050600Z --- 25.7S 54.0E
   MAX SUSTAINED WINDS - 025 KT, GUSTS 035 KT
   WIND RADII VALID OVER OPEN WATER ONLY
   DISSIPATED AS A SIGNIFICANT TROPICAL CYCLONE OVER WATER
    ---
REMARKS:
020900Z POSITION NEAR 21.2S 43.8E.
TROPICAL CYCLONE (TC) 13S (FAMI), LOCATED APPROXIMATELY 235 NM WEST-
SOUTHWEST OF ANTANANARIVO, MADAGASCAR, HAS TRACKED EAST-SOUTHEASTWARD
AT 08 KNOTS OVER THE PAST SIX HOURS. THIS SYSTEM HAS RAPIDLY CONSOLI-
DATED OVER THE PAST 12 HOURS. RECENT ANIMATED MULTISPECTRAL SATELLITE
IMAGERY SHOWS DEEP CONVECTION HAS DEVELOPED OVER A LOW LEVEL CIRCU-
LATION CENTER (LLCC), WITH A 020427Z SSMIS MICROWAVE PASS SHOWING AN
EYE FEATURE DEVELOPING IN THE MID- TO UPPER-LEVELS OF THE SYSTEM. THE
UPPER LEVEL ENVIRONMENT IS VERY FAVORABLE WITH A POINT SOURCE ANTI-
CYCLONE OVER THE LLCC PROVIDING AMPLE EQUATORWARD OUTFLOW WITH A
POLEWARD OUTFLOW CHANNEL STARTING TO DEVELOP. CURRENT DVORAK INTEN-
SITY FIXES FROM PGTW AND FMEE INDICATE THE SYSTEM IS AROUND 40 KNOTS
AND HAS IMPROVED DRASTICALLY OVER THE PAST 6 TO 12 HOURS. HOWEVER,
THE CURRENT TRACK IS TAKING TC 13S OVER THE SOUTHERN PORTION OF MADA-
GASCAR, AND THE FRICTIONAL EFFECTS OF LAND WILL CAUSE DISSIPATION TO
BEGIN IN THE NEXT 12 HOURS. THE CURRENT FORECAST FAVORS THE ECMF
SOLUTION, WITH THE LLCC BRIEFLY INTENSIFYING UPON MOVING BACK OVER
WATER, BUT STARTING TO WEAKEN DUE TO INCREASING VERTICAL WIND SHEAR
AFTER TAU 48. A SERIES OF MID-LATITUDE LOWS WILL CAUSE TC 13S TO MOVE
SOUTHEASTWARD WITH EVENTUAL CAPTURE AND FULL DISSIPATION BY TAU 72.
MODEL GUIDANCE HAS NOT HANDLED THE DEVELOPMENT OF TC 13S WELL, AND
AN ALTERNATE SCENARIO IS POSSIBLE WITH TC 13S BEING ABLE TO MAINTAIN
ITS STRUCTURE AND STRENGTHEN MORE SIGNIFICANTLY ONCE IT MOVES BACK
OVER WATER. THIS WARNING SUPERSEDES AND CANCELS REF A, NAVMARFCSTCEN
020221Z FEB 10 TROPICAL CYCLONE FORMATION ALERT (WTXS21 PGTW 020230)
MAXIMUM SIGNIFICANT WAVE HEIGHT AT 020600Z IS 10 FEET. NEXT WARNINGS
AT 022100Z AND 030900Z.//
=========================================================================
WTXS31 PGTW 022100
MSGID/GENADMIN/NAVMARFCSTCEN PEARL HARBOR HI/JTWC//
SUBJ/TROPICAL CYCLONE 13S (FAMI) WARNING NR 002//
RMKS/
1. TROPICAL CYCLONE 13S (FAMI) 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:
   021800Z --- NEAR 21.0S 45.5E
     MOVEMENT PAST SIX HOURS - 090 DEGREES AT 10 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 LAND
   REPEAT POSIT: 21.0S 45.5E
    ---
   FORECASTS:
   12 HRS, VALID AT:
   030600Z --- 21.3S 48.2E
   MAX SUSTAINED WINDS - 025 KT, GUSTS 035 KT
   WIND RADII VALID OVER OPEN WATER ONLY
   DISSIPATING AS A SIGNIFICANT TROPICAL CYCLONE OVER LAND
   VECTOR TO 24 HR POSIT: 095 DEG/ 15 KTS
    ---
   24 HRS, VALID AT:
   031800Z --- 21.6S 51.5E
   MAX SUSTAINED WINDS - 025 KT, GUSTS 035 KT
   WIND RADII VALID OVER OPEN WATER ONLY
   DISSIPATING AS A SIGNIFICANT TROPICAL CYCLONE OVER WATER
   VECTOR TO 36 HR POSIT: 120 DEG/ 20 KTS
    ---
   36 HRS, VALID AT:
   040600Z --- 23.6S 55.3E
   MAX SUSTAINED WINDS - 030 KT, GUSTS 040 KT
   WIND RADII VALID OVER OPEN WATER ONLY
   DISSIPATED AS A SIGNIFICANT TROPICAL CYCLONE OVER WATER
    ---
REMARKS:
022100Z POSITION NEAR 21.0S 45.5E.
TROPICAL CYCLONE (TC) 13S (FAMI), LOCATED APPROXIMATELY 150 NM
SOUTHWEST OF ANTANANARIVO, MADAGASCAR, HAS TRACKED EASTWARD AT 10
KNOTS OVER THE PAST SIX HOURS. ANIMATED INFRARED SATELLITE IMAGERY
SHOWS A SIGNIFICANT DECREASE AND DISORGANIZATION OF DEEP CONVECTION
AS TC 13S HAS TRACKED OVER MADAGASCAR. THE SYSTEM IS LOCATED BENEATH
AN UPPER LEVEL POINT SOURCE WHICH IS PROVIDING GOOD EQUATORWARD
OUTFLOW AND LOW VERTICAL WIND SHEAR. ADDITIONALLY, AN UPPER-LEVEL,
MID-LATITUDE LOW IS PROVIDING A SUBSTANTIAL POLEWARD OUTFLOW
CHANNEL. NEVERTHELESS, OVER THE NEXT 12 HOURS, TC 13S IS EXPECTED TO
CONTINUE WEAKENING DUE TO THE FRICTIONAL EFFECTS AND MOUNTAINOUS
TERRAIN OF MADAGASCAR AND ENTER THE INDIAN OCEAN AS A TROPICAL
DEPRESSION. THE NEAR EQUATORIAL RIDGE IS CURRENTLY STEERING TC 13S
EASTWARD, BUT WILL GIVE WAY TO THE SUBTROPICAL RIDGE BY TAU 24,
ENABLING A SOUTHEASTWARD TURN. BY TAU 36, THE SYSTEM IS EXPECTED TO
DISSIPATE AS A SIGNIFICANT TROPICAL CYCLONE. HOWEVER, AN ALTERNATE
SCENARIO REMAINS THAT TC 13S COULD START TO INTERACT WITH THE
BAROCLINIC ZONE AND BEGIN TRANSITIONING INTO AN EXTRATROPICAL
SYSTEM. AT THE SAME TIME, THE SYSTEM COULD ALSO INTENSIFY INTO A
WEAK TROPICAL CYCLONE AS THE POLEWARD OUTFLOW INTO THE MID-LATITUDES
TEMPORARILY IMPROVES. THERE IS CURRENTLY SOME UNCERTAINTY AS TO
WHETHER THE SYSTEM COULD STRENGTHEN AS A SIGNIFICANT TROPICAL
CYCLONE BEFORE IT COMPLETES A POTENTIAL EXTRA-TROPICAL TRANSITION.
MOST MODELS INDICATE DISSIPATION AT THIS POINT BUT THEY HAVE NOT
HANDLED THIS SYSTEM WELL IN GENERAL. 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 021800Z IS 8 FEET. REFER TO TROPICAL
CYCLONE 12P (OLI) WARNINGS (WTPS31 PGTW) FOR THE FINAL WARNING ON
THAT SYSTEM.//

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

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