WTXS21 PGTW 20090309 01:30z
MSGID/GENADMIN/NAVMARFCSTCEN PEARL HARBOR HI/JTWC//
SUBJ/TROPICAL CYCLONE FORMATION ALERT//
RMKS/
1. FORMATION OF A SIGNIFICANT TROPICAL CYCLONE IS POSSIBLE WITHIN
130 NM EITHER SIDE OF A LINE FROM 15.6S 83.7E TO 18.4S 87.2E
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 082330Z INDICATES THAT A CIRCULATION CENTER IS LOCATED
NEAR 15.9S 84.1E. THE SYSTEM IS MOVING EAST-SOUTHEASTWARD AT 10
KNOTS.
2. REMARKS: THE AREA OF CONVECTION PREVIOUSLY LOCATED NEAR 14.8S
82.3E, IS NOW LOCATED NEAR 15.9S 84.1E, APPROXIMATELY 860 NM
SOUTHEAST OF DIEGO GARCIA. ANIMATED INFRARED IMAGERY INDICATES THAT
THE LOW LEVEL CIRCULATION CENTER (LLCC) HAS CONTINUED TO CONSOLIDATE
WITH DEEP CONVECTION PERSISTING OVER THE SOUTHERN QUADRANT OF THE
LLCC. UPPER LEVEL ANALYSIS INDICATES THE LLCC IS CURRENTLY LOCATED
EQUATORWARD OF THE UPPER LEVEL SUBTROPICAL RIDGE AXIS, WHICH IS
PROVIDING AMPLE POLEWARD OUTFLOW. THE LOCATION OF THE LLCC IN
RELATION TO THE RIDGE AXIS IS HELPING TO KEEP THE VERTICAL WIND
SHEAR LOW. AN UPPER-LEVEL LONGWAVE TROUGH UPSTREAM HAS BEEN HELPING
TO ENHANCE POLEWARD OUTFLOW, BUT HAS KEPT THE VERTICAL WIND SHEAR
HIGH ON THE SOUTHWESTERN QUADRANT OF THE AREA. MAXIMUM SUSTAINED
SURFACE WINDS ARE ESTIMATED AT 25 TO 30 KNOTS. MINIMUM SEA
LEVEL PRESSURE IS ESTIMATED TO BE NEAR 1003 MB.
3. THIS ALERT WILL BE REISSUED, UPGRADED TO WARNING OR CANCELLED BY
100130Z.//
=========================================================================
WTXS32 PGTW 20090309 15:00z
1. TROPICAL CYCLONE 19S (NINETEEN) WARNING NR 001
   01 ACTIVE TROPICAL CYCLONE IN SOUTHIO
   MAX SUSTAINED WINDS BASED ON ONE-MINUTE AVERAGE
    ---
   WARNING POSITION:
   091200Z --- NEAR 18.4S 85.9E
     MOVEMENT PAST SIX HOURS - 160 DEGREES AT 11 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: 18.4S 85.9E
    ---
   FORECASTS:
   12 HRS, VALID AT:
   100000Z --- 19.2S 86.6E
   MAX SUSTAINED WINDS - 040 KT, GUSTS 050 KT
   WIND RADII VALID OVER OPEN WATER ONLY
   VECTOR TO 24 HR POSIT: 165 DEG/ 04 KTS
    ---
   24 HRS, VALID AT:
   101200Z --- 19.9S 86.8E
   MAX SUSTAINED WINDS - 035 KT, GUSTS 045 KT
   WIND RADII VALID OVER OPEN WATER ONLY
   VECTOR TO 36 HR POSIT: 215 DEG/ 02 KTS
    ---
   36 HRS, VALID AT:
   110000Z --- 20.3S 86.5E
   MAX SUSTAINED WINDS - 035 KT, GUSTS 045 KT
   WIND RADII VALID OVER OPEN WATER ONLY
   VECTOR TO 48 HR POSIT: 240 DEG/ 02 KTS
    ---
   EXTENDED OUTLOOK:
   48 HRS, VALID AT:
   111200Z --- 20.5S 86.1E
   MAX SUSTAINED WINDS - 035 KT, GUSTS 045 KT
   WIND RADII VALID OVER OPEN WATER ONLY
    ---
REMARKS:
091500Z POSITION NEAR 18.6S 86.1E.
TROPICAL CYCLONE (TC) 19S (NINETEEN), LOCATED APPROXIMATELY 1030 NM
SOUTHEAST OF DIEGO GARCIA, HAS TRACKED SOUTH-SOUTHEASTWARD AT 11
KNOTS OVER THE PAST 06 HOURS. THE CYCLONE HAS CONSOLIDATED DESPITE
MARGINAL UPPER LEVEL CONDITIONS. POLEWARD OUTFLOW HAS INCREASED
AHEAD OF AN UPPER-LEVEL TROUGH UPSTREAM, FUELING DEEP CONVECTION
OVER AN ALREADY WELL-DEFINED LOW LEVEL CIRCULATION CENTER AS
INDICATED BY EARLIER SCATTEROMETRY DATA. ON THE OTHER HAND, MODERATE
VERTICAL WIND SHEAR WITHIN THE SOUTHERN SEMICIRCLE IS DISRUPTING
SYMMETRY OF THE DEEP CONVECTION ABOUT THE LLCC, AND MORE RECENT
ANIMATED WATER VAPOR INDICATES THAT EQUATORWARD OUTFLOW HAS BECOME
STIFFLED AS WELL. THE INITIAL INTENSITY IS BASED ON DVORAK SATELLITE
INTENSITY ESTIMATES FROM PGTW AND FMME, WHICH BOTH INDICATE A 35-
KNOT SYSTEM. THE STORM IS FORECAST TO SLOW AS THE NEAR EQUATORIAL
STEERING RIDGE WEAKENS, ALLOWING FOR THE LOW LEVEL EASTERLIES TO
TRACK THE SYSTEM PROGRESSIVELY WESTWARD. INTENSITIES WILL HOVER NEAR
35 KNOTS FOR MOST OF THE FORECAST PERIOD AS THE STORM CONTINUES TO
CONTEND WITH MODERATE VERTICAL WIND SHEAR. VERTICAL WIND SHEAR
IS FORECAST TO INCREASE SLIGHTLY OVER THE NEXT 2 DAYS. THIS WARNING
SUPERSEDES AND CANCELS REF A, NAVMARFCSTCEN 090121Z MAR 09 TROPICAL
CYCLONE FORMATION ALERT (WTXS21 PGTW 090130 ) MAXIMUM SIGNIFICANT
WAVE HEIGHT AT 091200Z IS 8 FEET. NEXT WARNINGS AT 100300Z AND
101500Z.
=========================================================================
WTXS31 PGTW 20090310 03:00z
MSGID/GENADMIN/NAVMARFCSTCEN PEARL HARBOR HI/JTWC//
SUBJ/TROPICAL CYCLONE 19S (NINETEEN) WARNING NR 002//
RMKS/
1. TROPICAL CYCLONE 19S (NINETEEN) WARNING NR 002
   01 ACTIVE TROPICAL CYCLONE IN SOUTHIO
   MAX SUSTAINED WINDS BASED ON ONE-MINUTE AVERAGE
    ---
   WARNING POSITION:
   100000Z --- NEAR 19.1S 87.4E
     MOVEMENT PAST SIX HOURS - 090 DEGREES AT 04 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 WATER
   REPEAT POSIT: 19.1S 87.4E
    ---
   FORECASTS:
   12 HRS, VALID AT:
   101200Z --- 19.6S 87.5E
   MAX SUSTAINED WINDS - 025 KT, GUSTS 035 KT
   WIND RADII VALID OVER OPEN WATER ONLY
   DISSIPATED AS A SIGNIFICANT TROPICAL CYCLONE OVER WATER
   VECTOR TO 24 HR POSIT: 250 DEG/ 03 KTS
    ---
   24 HRS, VALID AT:
   110000Z --- 19.8S 86.9E
   MAX SUSTAINED WINDS - 025 KT, GUSTS 035 KT
   WIND RADII VALID OVER OPEN WATER ONLY
   DISSIPATED AS A SIGNIFICANT TROPICAL CYCLONE OVER WATER
    ---
REMARKS:
100300Z POSITION NEAR 19.2S 87.4E.
TROPICAL CYCLONE (TC) 19S (NINETEEN), LOCATED APPROXIMATELY 690 NM
SOUTHWEST OF COCOS ISLAND, HAS TRACKED EASTWARD AT 04 KNOTS OVER THE
PAST 06 HOURS. THE CYCLONE HAS WEAKENED CONSIDERABLY UNDER THE
DETRIMENTAL EFFECTS OF INCREASING VERTICAL WIND SHEAR (VWS). THE
EFFECTS OF THE VWS ARE EVIDENT IN A 091919Z AMSRE IMAGE SHOWING A
PARTIALLY EXPOSED LOW LEVEL CIRCULATION CENTER (LLCC) WITH THE
MAJORITY OF THE CONVECTION SHEARED TO THE SOUTHEAST. THE CURRENT
INTENSITY IS BASED UPON DVORAK ESTIMATES OF 30 KNOTS, AND A 091536Z
ASCAT PASS SHOWING 20 TO 25 KNOT WINDS NEAR THE CENTER. THE LLCC IS
FORECAST TO BECOME QUASI-STATIONARY UNDER WEAKENING STEERING
INFLUENCE AS THE STRUCTURE OF THE STORM DEGRADES WITH INCREASING
VERTICAL WIND SHEAR. 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 100000Z IS 10 FEET.

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

Document: tropical_cyclone_200919_jtwc_advisories.htm Updated: 17 June 2020 [Australian Severe Weather index] [Copyright Notice] [Email Contacts] [Search This Site] [Privacy Policy]