WDXS31 PGTW 242100
MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI//
SUBJ/PROGNOSTIC REASONING FOR TROPICAL CYCLONE 24S (JASMINE) WARNING 
NR 003//
RMKS/
1. FOR METEOROLOGISTS.
2. 6 HOUR SUMMARY AND ANALYSIS.

SUMMARY:
   INITIAL POSITION: 19.2S 39.5E
   INITIAL INTENSITY: 50 KTS
   GEOGRAPHIC REFERENCE: 184 NM NORTH-NORTHWEST OF EUROPA ISLAND
   MOVEMENT PAST 6 HOURS: SOUTHWARD AT 06 KTS
   SIGNIFICANT WAVE HEIGHT: 20 FEET

SATELLITE ANALYSIS, INITIAL POSITION AND INTENSITY DISCUSSION:
ANIMATED ENHANCED INFRARED (EIR) SATELLITE IMAGERY DEPICTS A
MEDIUM-SIZED SYSTEM IN THE MOZAMBIQUE CHANNEL THAT HAS SIGNIFICANTLY 
IMPROVED AS EVIDENCED BY A DEEPER AND MORE SYMMETRICAL  CENTRAL 
CONVECTION WITH WARM PIXELS IN THE MIDDLE, AN INDICATION OF POSSIBLE 
FORMATIVE EYE. THE INITIAL POSITION IS PLACED WITH MEDIUM CONFIDENCE 
UNDER THE WARM PIXELS, ADJUSTED FOR A POLEWARD TILT DUE TO MODERATE 
VERTICAL WIND SHEAR. THE INITIAL INTENSITY OF 50KTS IS ASSIGNED WITH 
MEDIUM CONFIDENCE BASED ON OVERALL ASSESSMENT OF AGENCY AND 
AUTOMATED DVORAK ESTIMATES AND CONSISTENT WITH THE 6-HR CONVECTIVE 
IMPROVEMENT.

INITIAL WIND RADII BASIS: RECENT SCATTEROMETER DATA.

CURRENT STEERING MECHANISM: SUBTROPICAL RIDGE (STR) TO THE EAST.  

AGENCY DVORAK AND AUTOMATED FIXES: 
   PGTW: T2.5 - 35 KTS
   FMEE: T3.5 - 55 KTS
   CIMSS SATCON: 53 KTS AT 241538Z
   CIMSS ADT: 43 KTS AT 241515Z

FORECASTER ASSESSMENT OF CURRENT ENVIRONMENT: FAVORABLE
   VWS: 20-25 KTS
   SST: 29-30 CELSIUS
   OUTFLOW: STRONG POLEWARD

ANALYSIS CONFIDENCE:
   INITIAL POSITION: MEDIUM
   INITIAL INTENSITY: MEDIUM
   INITIAL WIND RADII: MEDIUM

3. FORECAST REASONING.

SIGNIFICANT FORECAST CHANGES: THERE ARE NO SIGNIFICANT CHANGES TO
THE FORECAST FROM THE PREVIOUS WARNING.

FORECAST DISCUSSION: TC JASMINE WILL CONTINUE GENERALLY
SOUTH-SOUTHEASTWARD UNDER THE STEERING INFLUENCE OF THE STR TO THE
EAST. THE FAVORABLE ENVIRONMENT WILL QUICKLY BECOME UNFAVORABLE DUE
TO INCREASING VWS AND THE INFLUX OF COLD DRY AIR IN THE LOWER
LEVELS, LEADING TO A GRADUAL DISSIPATION TO 30KTS BY TAU 48. AROUND
TAU 24, A MID-LATITUDE TROUGH TRANSITING FROM THE SOUTHWEST WILL
WEAKEN THE STR. THIS WILL RESULT IN A SLOW EASTWARD MOTION DUE TO
THE WEAKENED STEERING ENVIRONMENT. 


MODEL DISCUSSION: NUMERICAL MODELS ARE IN GENERAL AGREEMENT WITH A
POLEWARD THEN EASTWARD TRAJECTORY, ALBEIT WIDELY SPREAD TO 380NM
BY TAU 48 WITH NAVGEM ON THE LEFT AND GFS ON THE RIGHT MARGIN OF THE 
MODEL ENVELOPE. IN VIEW OF THIS, THE JTWC TRACK FORECAST IS LAID 
CLOSE TO THE MODEL CONSENSUS WITH MEDIUM CONFIDENCE. 


FORECAST CONFIDENCE:
   TRACK 0 - 72 HR: MEDIUM
   INTENSITY 0 - 72 HR: MEDIUM//
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