WDIO31 PGTW 252100
MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI//
SUBJ/PROGNOSTIC REASONING FOR TROPICAL CYCLONE 03B (GULAB) WARNING 
NR 007//
RMKS/
1. FOR METEOROLOGISTS.
2. 6 HOUR SUMMARY AND ANALYSIS.

SUMMARY:
   INITIAL POSITION: 18.2N 88.3E
   INITIAL INTENSITY: 40 KTS
   GEOGRAPHIC REFERENCE: 264 NM SOUTH OF KOLKATA, INDIA
   MOVEMENT PAST 6 HOURS: WESTWARD AT 05 KTS
   SIGNIFICANT WAVE HEIGHT: 16 FEET

SATELLITE ANALYSIS, INITIAL POSITION AND INTENSITY DISCUSSION:
ANIMATED ENHANCED INFRARED (EIR) SATELLITE IMAGERY DEPICTS A DENSE
CONVECTIVE CANOPY OBSCURING LOWER LEVEL BANDING. THE LAST USEFUL
MICROWAVE PASS WAS FROM SSMIS AT 251225Z, INDICATING THE LOW LEVEL
CIRCULATION CENTER (LLCC) WAS TRAILING BEHIND THE CONVECTIVE MASS,
WHICH IS BEING SUBJECTED TO NORTHEASTERLY WIND SHEAR. THE INITIAL
POSITION WAS BASED ON LOW-CONFIDENCE AGENCY FIX POSITIONS AND
PERSISTENCE, AND MAINTAINS THE POSITION SLIGHTLY EAST OF THE DEEP
CONVECTION. THE INITIAL INTENSITY WAS HELD AT 40 KNOTS, WHICH IS
SLIGHTLY ABOVE THE DEMS AND PGTW T2.5 (35 KNOT) DVORAK ESTIMATES TO
ACCOUNT FOR HIGHER ADT AND SATCON VALUES. THE LAST USEFUL
SCATTEROMETRY DATA WAS FROM A 251330Z ASCAT-A PASS, DEPICTING 35
KNOTS AROUND THE LLCC. THE CIMSS VERTICAL WIND SHEAR PRODUCT NOW
ESTIMATES SHEAR HAS INCREASED TO 20-25 KNOTS. THERE IS MODERATE
UPPER LEVEL OUTFLOW SUPPORT.

INITIAL WIND RADII BASIS: PERSISTENCE AND OBJECTIVE BEST TRACK 

CURRENT STEERING MECHANISM: SOUTHERN PERIPHERY OF AN EXTENSION OF
A DEEP SUBTROPICAL RIDGE (STR)TO THE NORTH.

AGENCY DVORAK AND AUTOMATED FIXES: 
   PGTW: T2.5 - 35 KTS
   DEMS: T2.5 - 35 KTS
   CIMSS SATCON: 50 KTS AT 251607Z
   CIMSS ADT: 53 KTS AT 251815Z

FORECASTER ASSESSMENT OF CURRENT ENVIRONMENT: MARGINAL
   VWS: 15-25 KTS
   SST: 29-30 CELSIUS
   OUTFLOW: MODERATE WESTWARD

ANALYSIS CONFIDENCE:
   INITIAL POSITION: LOW
   INITIAL INTENSITY: LOW
   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 FORECAST TO CONTINUE
TRACKING PRIMARILY WESTWARD THROUGH THE DURATION OF THE FORECAST
PERIOD, ALONG THE SOUTHERN PERIPHERY OF THE EXTENSION OF THE DEEP
STR TO THE NORTH. THE SYSTEM IS EXPECTED TO MAKE LANDFALL ALONG THE
INDIAN COASTLINE NORTH OF VISHAKHAPATNAM SHORTLY AFTER TAU 24. THE
UPTICK IN VERTICAL WIND SHEAR IS EXPECTED TO LIMIT FURTHER
INTENSIFICATION PRIOR TO LANDFALL, HOWEVER, THE MODERATE OUTFLOW
AND WARM SSTS SHOULD ALLOW 03B TO MAINTAIN ITS TROPICAL STORM
STATUS AS IT MAKES LANDFALL. ONCE ASHORE, THE SYSTEM WILL RAPIDLY
DISSIPATE OVER THE RUGGED TERRAIN TO THE NORTHWEST OF
VISHAKHAPATNAM, ALTHOUGH, SOME MODELS ARE INDICATING THE REMNANT
ENERGY MAY TRACK ACROSS THE CONTINENT AND RE-EMERGE OVER THE
ARABIAN SEA SEVERAL DAYS LATER.

MODEL DISCUSSION: GUIDANCE FOR THE SHORT TRACK IS IN
GENERALLY GOOD AGREEMENT, EXCEPT FOR UKMET-BASED GUIDANCE WHICH
TAKES 03B ON A MORE SOUTHWESTERLY TRACK PRIOR TO LANDFALL. THE JTWC
FORECAST LIES WITHIN THE TIGHTEST GROUPING OF MODELS, CLOSE TO THE
CONSENSUS MEAN WITH HIGH CONFIDENCE. THE INTENSITY GUIDANCE IS ALSO
IN GOOD AGREEMENT WITH A STEADY TO SLIGHT WEAKENING FORECAST PRIOR
TO LANDFALL. 

FORECAST CONFIDENCE:
   TRACK 0 - 72 HR: HIGH
   TRACK 72-120 HR: ---
   INTENSITY 0 - 72 HR: HIGH
   INTENSITY 72-120 HR: ---//
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