WDXS32 PGTW 271500
MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI//
SUBJ/PROGNOSTIC REASONING FOR TROPICAL CYCLONE 22S (HALIMA) WARNING 
NR 009//
RMKS/
1. FOR METEOROLOGISTS.
2. 6 HOUR SUMMARY AND ANALYSIS.

SUMMARY:
   INITIAL POSITION: 21.0S 78.1E
   INITIAL INTENSITY: 50 KTS
   GEOGRAPHIC REFERENCE: 895 NM SOUTH-SOUTHEAST OF DIEGO GARCIA
   MOVEMENT PAST 6 HOURS: EAST-SOUTHEASTWARD AT 13 KTS
   SIGNIFICANT WAVE HEIGHT: 22 FEET

SATELLITE ANALYSIS, INITIAL POSITION AND INTENSITY DISCUSSION:
ANIMATED ENHANCED INFRARED (EIR) SATELLITE IMAGERY DEPICTS A
RAPIDLY ERODING SYSTEM WITH ALL ASSOCIATED CONVECTION SHEARED
SOUTHEASTWARD OF THE LOW LEVEL CIRCULATION. THE INITIAL POSITION IS
PLACED WITH HIGH CONFIDENCE BASED ON A PINHOLE MICROWAVE EYE
FEATURE IN THE 271123Z SSMIS 89GHZ IMAGE. THE INITIAL INTENSITY OF
50KTS IS BASED ON AN OVERALL ASSESSMENT OF AGENCY AND AUTOMATED
DVORAK ESTIMATES AND REFLECTS THE RAPID DETERIORATION. ANALYSIS
INDICATES A HIGHLY UNFAVORABLE ENVIRONMENT WITH WARM SST AND STRONG
POLEWARD OUTFLOW COMPLETELY OFFSET BY STRONG VWS AND COLD DRY AIR
INTRUSION IN THE LOW LEVELS. THE CYCLONE IS TRACKING ALONG THE
SOUTHWESTERN PERIPHERY OF THE NER TO THE NORTHEAST.

INITIAL WIND RADII BASIS: SCATTEROMETER DATA 

CURRENT STEERING MECHANISM: NEAR EQUATORIAL RIDGE (NER) TO THE
NORTHEAST.

AGENCY DVORAK AND AUTOMATED FIXES: 
   PGTW: T3.5 - 55 KTS
   FMEE: T3.5 - 55 KTS
   FIMP: T3.5 - 55 KTS
   CIMSS SATCON: 50 KTS AT 270826Z
   CIMSS ADT: 34 KTS AT 270915Z

FORECASTER ASSESSMENT OF CURRENT ENVIRONMENT: HIGHLY UNFAVORABLE
   VWS: 20-25 KTS
   SST: 27-28 CELSIUS
   OUTFLOW: STRONG POLEWARD

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

3. FORECAST REASONING.

SIGNIFICANT FORECAST CHANGES: FORECAST TRACK HAS BEEN CURTAILED TO
48 HRS IN ANTICIPATION OF EARLIER DISSIPATION.

FORECAST DISCUSSION: TC HALIMA WILL TRACK MORE EASTWARD THEN
NORTHEASTWARD AS THE NER EXTENDS WESTWARD. THE HIGHLY UNFAVORABLE
CONDITIONS WILL PREVAIL ALONG THE TRACK AND CONTINUE TO RAPIDLY
ERODE THE SYSTEM TO DISSIPATION BY TAU 48, POSSIBLY SOONER. 

MODEL DISCUSSION: NUMERICAL MODELS ARE IN OVERALL GOOD AGREEMENT UP
TO TAU 24; AFTERWARD, THE MODELS SIGNIFICANTLY DIVERGE IN OPPOSITE
DIRECTIONS WITH SOME MEMBERS INCLUDING ECMWF, GFS, AEMN, AND EEMN
LOOPING THE VORTEX NORTHWESTWARD AND OTHER MEMBERS INCLUDING UEMN,
NAVGEM, AND UKMET CONTINUING ON AN EAST-SOUTHEASTWARD TRAJECTORY.
IN VIEW OF THESE, THERE IS ONLY MEDIUM CONFIDENCE IN THE JTWC TRACK
FORECAST THAT IS LAID CLOSE TO THE MODEL CONSENSUS.  

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