WDIO31 PGTW 250300
MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI//
SUBJ/PROGNOSTIC REASONING FOR TROPICAL CYCLONE 03B (THREE) WARNING NR 
004//
RMKS/
1. FOR METEOROLOGISTS.
2. 6 HOUR SUMMARY AND ANALYSIS.

SUMMARY:
   INITIAL POSITION: 18.2N 89.2E
   INITIAL INTENSITY: 40 KTS
   GEOGRAPHIC REFERENCE: 268 NM SOUTH OF KOLKATA, INDIA
   MOVEMENT PAST 6 HOURS: WESTWARD AT 09 KTS
   SIGNIFICANT WAVE HEIGHT: 14 FEET

SATELLITE ANALYSIS, INITIAL POSITION AND INTENSITY DISCUSSION:
ANIMATED ENHANCED INFRARED (EIR) SATELLITE IMAGERY SHOWS SOME
CONSOLIDATION AND IMPROVING ORGANIZATION DURING THE PAST SIX HOURS,
WITH DEEP CONVECTION CONSOLIDATING OVER A RELATIVELY SMALL CORE.
THE SYSTEM IS TRACKING THROUGH AN AREA OF 10-15KT VERTICAL WIND
SHEAR AND 29C SEA WATERS. ANIMATED WATER VAPOR IMAGERY SHOWS
IMPROVING OUTFLOW AND TOTAL PRECIPITABLE WATER LOOPS CONFIRM DEEP
MOISTURE COVERS THE ENTIRE BAY OF BENGAL. OTHER THAN A MILD
INCREASE IN WIND SHEAR NEAR THE EAST COAST OF INDIA, THE
ENVIRONMENT ALONG TRACK IS CONSISTENT THROUGH LANDFALL. THE CURRENT
INTENSITY IS BASED ON SATCON AND ADT ASSESSMENTS.

INITIAL WIND RADII BASIS: PERSISTENCE FROM A 241547Z METOP-C ASCAT.

CURRENT STEERING MECHANISM: THE WESTERN EXTENSION OF THE
SUBTROPICAL RIDGE OVER SOUTHEAST ASIA.

AGENCY DVORAK AND AUTOMATED FIXES: 
   PGTW: T2.0 - 30 KTS
   CIMSS SATCON: 40 KTS AT 241925Z
   CIMSS ADT: 39 KTS AT 242115Z

FORECASTER ASSESSMENT OF CURRENT ENVIRONMENT: MARGINAL
   VWS: 10-15 KTS
   SST: 28-30 CELSIUS
   OUTFLOW: MODERATE RADIAL

ANALYSIS CONFIDENCE:
   INITIAL POSITION: MEDIUM
   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 03B IS EXPECTED TO TRACK
STEADILY WESTWARD THROUGH A CONSISTENT ENVIRONMENT CHARACTERIZED BY
WARM SEAS AND LIGHT TO MODERATE VERTICAL WIND SHEAR. IT WILL
INTENSIFY SLIGHTLY DURING THE NEXT 24 HOURS BEFORE ENCOUTNERING
INCREASING NORTHEASTERLY SHEAR PRIOR TO LANDFALL.  

MODEL DISCUSSION: TRACK GUIDANCE IS CONSISTENT IN BOTH TRACK AND
SPEED. THE JTWC FORECAST RIDES THE MULTI-MODEL CONSENSUS. INTENSITY
GUIDANCE SEEMS TO BE STRUGGLING TO RECONCILE THE GOOD OCEANOGRAPHIC
CONDITIONS WITH A VARIABLE VERTICAL WIND SHEAR GRADIENT. THE
FARTHER POLEWARD THE SYSTEM TRACKS, THE LIGHTER THE SHEAR, BUT AS
THE SYSTEM APPROACHES THE INDIAN SUBCONTINENT IT WILL ENCOUNTER 
INCREASING NORTHEASTERLY SHEAR ORIGINATING FROM THE SEASONAL UPPER 
LEVEL ANTICYCLONE AT THE BASE OF THE HIMALAYAS. THE JTWC FORECAST 
STAYS JUST BELOW THE STATISTICAL DYNAMICAL GUIDANCE, CLOSER TO HWRF. 

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