WDIO31 PGTW 300300
MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI//
SUBJ/PROGNOSTIC REASONING FOR TROPICAL CYCLONE 02A (TWO) WARNING NR 
001//
RMKS/
1. FOR METEOROLOGISTS.
2. 6 HOUR SUMMARY AND ANALYSIS.

SUMMARY:
   INITIAL POSITION: 23.4N 68.3E
   INITIAL INTENSITY: 35 KTS
   GEOGRAPHIC REFERENCE: 110 NM SOUTHEAST OF KARACHI, PAKISTAN
   MOVEMENT PAST 6 HOURS: SOUTH-SOUTHWESTWARD AT 06 KTS
   SIGNIFICANT WAVE HEIGHT: 12 FEET

SATELLITE ANALYSIS, INITIAL POSITION AND INTENSITY DISCUSSION:
ANIMATED ENHANCED INFRARED (EIR) SATELLITE IMAGERY DEPICTS
PERSISTENT CONVECTIVE BANDS WRAPPING IN TO A PARTIAL EXPOSED
LOW-LEVEL CIRCULATION CENTER (LLCC). CONVECTION IS DISPLACED TO THE
SOUTHWEST DUE TO MODERATE 15-20KT NORTHEASTERLY SHEAR. WATER VAPOR
IMAGERY REVEALS STRONG EQUATORWARD OUTFLOW INTO A REGION OF
DIVERGENT FLOW ALOFT. THE INITIAL POSITION IS PLACED WITH HIGH
CONFIDENCE BASED ON THE AFOREMENTIONED EIR AND RADAR IMAGERY. THE
INITIAL INTENSITY OF 35 KTS IS ASSESSED WITH HIGH CONFIDENCE BASED
ON THE INITIAL INTENSITY OF 35 KTS IS ASSESSED WITH LOW CONFIDENCE
BASED ON THE AGENCY FIXES LISTED BELOW.

INITIAL WIND RADII BASIS: OBJECTIVE BEST TRACK 

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

AGENCY DVORAK AND AUTOMATED FIXES: 
   PGTW: T1.5 - 25 KTS
   KNES: T1.0 - 25 KTS

FORECASTER ASSESSMENT OF CURRENT ENVIRONMENT: MARGINALLY FAVORABLE
   VWS: 10-15 KTS
   SST: 28-29 CELSIUS
   OUTFLOW: STRONG EQUATORWARD

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

3. FORECAST REASONING.

SIGNIFICANT FORECAST CHANGES: THIS INITIAL PROGNOSTIC REASONING
MESSAGE ESTABLISHES THE FORECAST PHILOSOPHY.

FORECAST DISCUSSION: TROPICAL CYCLONE (TC) 02A IS FORECAST TO TRACK
WESTWARD TOWARDS THE GULF OF OMAN ON THE SOUTHERN PERIPHERY OF A
NER TO THE NORTH-NORTHEAST THROUGH THE END OF THE FORECAST PERIOD.
AS THE SYSTEM MOVES AWAY FROM LAND, VERTICAL WIND SHEAR WILL WEAKEN
BY TAU 24 ALLOWING FOR INTENSIFICATION TO A PEAK OF 40KTS WHILE IN
AN OTHERWISE MARGINALLY FAVORABLE ENVIRONMENT WITH WARM SEA SURFACE
TEMPERATURES AND MODERATE UPPER-LEVEL DIVERGENCE DUE TO THE COL TO
THE NORTHWEST AND RIDGE TO THE NORTHEAST. AS THE TRACK MOVES
WESTWARD THROUGH THE END OF THE FORECAST, INTENSIFICATION WILL HALT
WHILE WITHIN THE PATH OF THE SOMALI JET, WHICH AS AN ALTERED AIR
MASS HAS A CHARACTERISTIC SURFACE INVERSION EXPECTED TO INTRODUCE
STABLE AIR INTO THE CIRCULATION AND INCREASE SHEAR TO UNFAVORABLE
LEVELS BY TAU 72. WHILE SHEARED AND COOLER AIR IS ENTRAINED INTO
THE SYSTEM AT THE SURFACE, THE INTENSITY IS FORECAST TO GRADUALLY
WEAKEN TO 35KTS BY TAU 48 AND REACH DISSIPATION BY TAU 72. 

MODEL DISCUSSION: DETERMINISTIC MODEL GUIDANCE IS IN GOOD AGREEMENT
THAT THE SYSTEM WILL TRACK WESTWARD THROUGH THE END OF THE FORECAST
PERIOD AFFIRMED BY A MAXIMUM CROSS-TRACK SPREAD OF 120NM BY TAU 72.
THE OCEAN-COUPLED INTENSITY GUIDANCE IS IN GOOD AGREEMENT WITHIN
THE MESOSCALE MODELS; HOWEVER, THE PRIMARY OUTLIER IS GFS WHICH
QUICKLY PEAKS TO 45KTS AT TAU 12 AND A HIGHER PEAK OF 50KTS BY TAU
48. THE JTWC INTENSITY FORECAST LIES CLOSELY TO THE CONSENSUS TRACK
MAINTAINING 30-35KTS THROUGH TAU 60 BEFORE WEAKENING TO
DISSIPATION.

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