WDIO31 PGTW 301500
MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI//
SUBJ/PROGNOSTIC REASONING FOR TROPICAL CYCLONE 02A (TWO) WARNING NR 
003//
RMKS/
1. FOR METEOROLOGISTS.
2. 6 HOUR SUMMARY AND ANALYSIS.

SUMMARY:
   INITIAL POSITION: 23.9N 66.8E
   INITIAL INTENSITY: 35 KTS
   GEOGRAPHIC REFERENCE: 55 NM SOUTH OF KARACHI, PAKISTAN
   MOVEMENT PAST 6 HOURS: NORTHWESTWARD AT 09 KTS
   SIGNIFICANT WAVE HEIGHT: 12 FEET

SATELLITE ANALYSIS, INITIAL POSITION AND INTENSITY DISCUSSION:
ANIMATED ENHANCED INFRARED (EIR) SATELLITE IMAGERY AND A COMPOSITE
RADAR LOOP SHOWS A SMALL SYSTEM IN THE ARABIAN SEA WITH FLARING
CONVECTIVE BANDS FEEDING INTO A PARTIALLY EXPOSED LOW LEVEL
CIRCULATION (LLC). THE CENTRAL CONVECTION IS DISPLACED TO THE
SOUTHWEST DUE TO MODERATE NORTHEASTERLY VWS. THE INITIAL POSITION
IS PLACED WITH HIGH CONFIDENCE BASED ON THE LLC IN THE RADAR LOOP 
THAT LINED UP WELL WITH A MICROWAVE LLC FEATURE IN THE 301138Z SSMIS 
IMAGE. THE INITIAL INTENSITY OF 35KTS IS ASSESSED WITH MEDIUM
CONFIDENCE BASED ON THE HIGH END OF AGENCY AND AUTOMATED DVORAK
ESTIMATES. ANALYSIS INDICATES A MARGINALLY FAVORABLE ENVIRONMENT
WITH WARM SST AND STRONG EQUATORWARD OUTFLOW OFFSET BY MODERATE VWS
AND DRY AIR INTRUSION AT THE LOW LEVELS.

INITIAL WIND RADII BASIS: PERSISTENCE.

CURRENT STEERING MECHANISM: AN EXTENSION OF A SUBTROPICAL RIDGE
(STR) TO THE NORTH-NORTHEAST. 

AGENCY DVORAK AND AUTOMATED FIXES: 
   PGTW: T1.5 - 25 KTS
   DEMS: T2.5 - 35 KTS
   CIMSS ADT: 33 KTS AT 301200Z
   CIMSS AIDT: 33 KTS AT 301200Z
   CIMSS DPRNT: 34 KTS AT 301200Z
   CIMSS DMNT: 41 KTS AT 301139Z

FORECASTER ASSESSMENT OF CURRENT ENVIRONMENT: MARGINALLY FAVORABLE
   VWS: 15-20 KTS
   SST: 28-29 CELSIUS
   OUTFLOW: STRONG EQUATORWARD

ANALYSIS CONFIDENCE:
   INITIAL POSITION: HIGH
   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 02A WILL CONTINUE TO TRACK MORE WESTWARD
UNDER THE STEERING STR TOWARD THE GULF OF OMAN. AS THE SYSTEM
TRACKS IN-PHASE WITH THE UPPER LEVEL WIND FLOW, RELATIVE VWS WILL
WEAKEN ALLOWING THE SYSTEM TO MAINTAIN ITS CURRENT INTENSITY. AFTER
TAU 36, VWS WILL ONCE AGAIN INCREASE, THIS PLUS THE PERSISTENT
INFLUX OF DRY AIR WILL LEAD TO DISSIPATION BY TAU 48, POSSIBLY
SOONER. 


MODEL DISCUSSION: NUMERICAL MODELS ARE IN TIGHT AGREEMENT WITH AN
EVEN SPREAD TO A MERE 88NM BY TAU 48, LENDING HIGH CONFIDENCE IN
THE JTWC TRACK FORECAST. GIVEN THE POSSIBILITY OF AN EARLIER
DISSIPATION, THERE IS ONLY MEDIUM CONFIDENCE IN THE JTWC INTENSITY
FORECAST. 

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