WDXS32 PGTW 152100
MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI//
SUBJ/PROGNOSTIC REASONING FOR TROPICAL CYCLONE 25S (JUDE) WARNING NR 
010//
RMKS/
1. FOR METEOROLOGISTS.
2. 6 HOUR SUMMARY AND ANALYSIS.

SUMMARY:
   INITIAL POSITION: 25.3S 47.7E
   INITIAL INTENSITY: 50 KTS
   GEOGRAPHIC REFERENCE: 384 NM SOUTH OF ANTANANARIVO, MADAGASCAR
   MOVEMENT PAST 6 HOURS: EASTWARD AT 15 KTS
   SIGNIFICANT WAVE HEIGHT: 24 FEET

SATELLITE ANALYSIS, INITIAL POSITION AND INTENSITY DISCUSSION:
ANIMATED ENHANCED INFRARED (EIR) SATELLITE IMAGERY DEPICTS SPIRAL
BANDING WRAPPING AROUND AN INCREASINGLY DISORGANIZED CORE OF DEEP
CORE OF DEEP CONVECTION DISPLACED TO THE SOUTH-SOUTHEAST OF A
RAGGED LOW LEVEL CENTER (LLC) WHICH IS PARTIALLY EXPOSED DUE TO THE
PRESENCE OF STRONG 40 TO 50 KT DEEP LAYER VERTICAL WIND SHEAR
(VWS). DESPITE THE PARTIAL EXPOSE, TRACKING OF THE LLC HAS BEEN
CHALLENGING AS THE CIRCULATION WAS DISRUPTED BY PASSAGE OVER THE
TERRAIN OF SOUTHERN MADAGASCAR, COMBINED WITH AN OVERALL SCARCITY
OF MICROWAVE DATA AND OCEAN SURFACE WIND PRODUCTS. WHILE A 151824Z
ASCAT-C OVERPASS DID NOT HAVE COVERAGE OVER THE LLC, IT HELPED
ESTABLISH THAT THE POSITION IS NORTHEAST OF AN INITIAL ASSESSMENT,
LEADING TO A REPOSITIONING OF THE 1518Z BEST TRACK. THE ASCAT ALSO
PROVIDED INSIGHT INTO THE LARGE GALE FORCE WIND FIELD TO THE SOUTH
OF THE LLC. GIVEN THE VWS VECTOR, THE UPDATED POSITION WAS ANALYZED
TO BE NORTHWEST OF A DEFINED MID-LEVEL CENTER IN A 151820Z AMSU-B
89GHZ IMAGE, ALBEIT WITH LOW CONFIDENCE. THE INTENSITY WAS ASSESSED
WITH MEDIUM CONFIDENCE TO BE 50 KNOTS, GIVEN A RANGE OF DVORAK
VALUES FROM T3.0 TO T3.5. CIMSS OBJECTIVE AIDS RANGE FROM GENERALLY
45 TO 55 KNOTS. SEA SURFACE TEMPERATURES ARE ESTIMATED TO BE 28
DEGREES CELSIUS. VERY STRONG POLEWARD OUTFLOW ENHANCED BY A NEARBY
SUBTROPICAL JET MAX IS PARTIALLY OFFSETTING THE OTHERWISE
UNFAVORABLE CONDITIONS ASSOCIATED WITH STRONG VWS AND LOW MID-LEVEL
RELATIVE HUMIDITY.

INITIAL WIND RADII BASIS: OBJECTIVE BEST TRACK WITH ASCAT PROVIDING
35 KT INPUT FOR SOUTHERN SEMICIRCLE

CURRENT STEERING MECHANISM: SUBTROPICAL RIDGE TO THE EAST

AGENCY DVORAK AND AUTOMATED FIXES: 
   PGTW: T3.0 - 45 KTS
   KNES: T3.0 - 45 KTS
   FMEE: T3.5 - 55 KTS
   CIMSS SATCON: 60 KTS AT 151645Z
   CIMSS ADT: 55 KTS AT 151800Z

FORECASTER ASSESSMENT OF CURRENT ENVIRONMENT: UNFAVORABLE
   VWS: 40+ KTS
   SST: 27-28 CELSIUS
   OUTFLOW: STRONG POLEWARD
   OTHER FACTORS: ASSESSED AS TROPICAL BUT BEGINNING SUBTROPICAL
TRANSITION

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

3. FORECAST REASONING.

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

FORECAST DISCUSSION: TROPICAL CYCLONE 25S IS FORECAST TO CONTINUE
TRACKING SOUTHEASTWARD UNDER THE INFLUENCE OF THE STEERING STR. SST
SHOULD CONTINUE TO DECLINE, AND VWS WILL REMAIN HIGH DUE TO A
LONGWAVE TROUGH PASSING OVERHEAD. SUBTROPICAL TRANSITION IS
BEGINNING AND IS EXPECTED TO COMPLETE WITHIN 24 HOURS. GIVEN THE
STRONG JET SUPPORT, LITTLE WEAKENING IS EXPECTED DURING THE
FORECAST PERIOD. 

MODEL DISCUSSION: MODEL GUIDANCE IS IN FAIR AGREEMENT IN THE
CROSS-TRACK DIRECTION, HOWEVER, UNCERTAINTY IN THE INITIAL POSITION
CARRIES THROUGH THE 24 HOUR FORECAST. THERE IS ALSO A LARGE SPREAD
IN ALONG TRACK POSITIONS, WITH MUCH FASTER FORWARD SPEEDS SEEN IN
GFS AND ITS ENSEMBLE COMPARED TO ECMWF AND ITS ENSEMBLE. THE TRACK
WAS PLACED SLIGHTLY FASTER THAN THE CONSENSUS MEAN. 

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