WDIO31 PGTW 130300
MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI//
SUBJ/PROGNOSTIC REASONING FOR TROPICAL CYCLONE 02A (BIPARJOY)   
WARNING NR 028//
RMKS/
1. FOR METEOROLOGISTS.
2. 6 HOUR SUMMARY AND ANALYSIS.

SUMMARY:
   INITIAL POSITION: 20.7N 67.1E
   INITIAL INTENSITY: 90 KTS
   GEOGRAPHIC REFERENCE: 246 NM SOUTH OF KARACHI, PAKISTAN
   MOVEMENT PAST 6 HOURS: NORTH-NORTHWESTWARD AT 05 KTS
   SIGNIFICANT WAVE HEIGHT: 30 FEET

SATELLITE ANALYSIS, INITIAL POSITION AND INTENSITY DISCUSSION:
ANIMATED ENHANCED INFRARED (EIR) SATELLITE IMAGERY DEPICTS A LARGE, 
ASYMMETRIC CENTRAL DENSE OVERCAST OBSCURING THE LOW-LEVEL CIRCULATION 
CENTER (LLCC) WITH DEEP CONVECTION RAPIDLY CYCLING. EIR IMAGERY SHOWS 
THE BULK OF THE INTENSE CORE CONVECTION DISPLACED OVER THE SOUTHERN 
SEMICIRCLE. A 122338Z SSMIS 91GHZ MICROWAVE IMAGE REVEALS SLIGHTLY 
IMPROVED CORE STRUCTURE WITH A WELL-DEFINED MICROWAVE EYE AND SPIRAL 
BANDING OVER THE SOUTHERN SEMICIRCLE. THE SSMIS 37GHZ MICROWAVE IMAGE 
INDICATES THAT THE UPPER-LEVEL CIRCULATION CENTER IS TILTED ABOUT 10NM
WEST OF THE LLCC DUE TO MODERATE NORTHEASTERLY VERTICAL WIND SHEAR 
(VWS). THE PERSISTENT VWS IS OFFSET BY MODERATE WESTWARD OUTFLOW,
WEAK POLEWARD OUTFLOW AND WARM SEA SURFACE TEMPERATURES. THE INITIAL 
INTENSITY OF 90 KTS IS ASSESSED WITH HIGH CONFIDENCE BASED ON THE 
AGENCY DVORAK ESTIMATES, A 122128Z AMSR2 WINDSPEED IMAGE SHOWING 
MAXIMUM WINDS OF 92-93 KNOTS AND A 122340Z D-MINT ESTIMATE OF 88 
KNOTS. 

INITIAL WIND RADII BASIS: AMSR2 WINDSPEED IMAGE

CURRENT STEERING MECHANISM: DEEP-LAYERED SUBTROPICAL RIDGE (STR)
POSITIONED TO THE EAST OVER WESTERN INDIA

AGENCY DVORAK AND AUTOMATED FIXES: 
   PGTW: T5.0 - 90 KTS
   KNES: T5.0 - 90 KTS
   CIMSS SATCON: 87 KTS AT 122121Z
   CIMSS ADT: 79 KTS AT 130000Z

FORECASTER ASSESSMENT OF CURRENT ENVIRONMENT: MARGINALLY FAVORABLE
   VWS: 20-25 KTS
   SST: 30-31 CELSIUS
   OUTFLOW: MODERATE WESTWARD

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

3. FORECAST REASONING.

SIGNIFICANT FORECAST CHANGES: THERE ARE NO SIGNIFICANT CHANGES TO
THE FORECAST FROM THE PREVIOUS WARNING.

FORECAST DISCUSSION: TROPICAL CYCLONE (TC) 02A HAS REMAINED 
SURPRISINGLY RESILIENT AND IS ONCE AGAIN FIGHTING THE PERSISTENT VWS 
WITH EXPANDING UPSHEAR OUTFLOW AND SLIGHTLY IMPROVED ORGANIZATION. 
OVERALL, THE SHORT-TERM FORECAST HAS REMAINED CHALLENGING, HOWEVER, 
THE SYSTEM IS EXPECTED TO MAINTAIN INTENSITY AT 90 KNOTS THROUGH TAU 
24 BUT COULD POSSIBLY PEAK HIGHER IF IT'S ABLE TO DEVELOP AN EYE. 
AFTER TAU 24, TC 02A WILL RECURVE NORTHEASTWARD WITH GRADUAL WEAKENING  
THROUGH TAU 60 AS THE SYSTEM INTERACTS WITH LAND. AFTER LANDFALL AT 
TAU 60 NEAR THE PAKISTAN-INDIA BORDER, RAPID WEAKENING IS EXPECTED 
WITH DISSIPATION OCCURRING AS THE SYSTEM TRACKS FURTHER INLAND.  

MODEL DISCUSSION: WITH THE EXCEPTION OF NAVGEM, WHICH REMAINS THE SOLE 
OUTLIER WITH A NORTHWARD TRACK, NUMERICAL MODEL GUIDANCE REMAINS IN 
FAIR AGREEMENT WITH AN 85NM SPREAD IN GUIDANCE AT LANDFALL NEAR THE
PAKISTAN-INDIA BORDER REGION. IN GENERAL, THE 121800Z ECMWF AND
GFS ENSEMBLES INDICATE A SIMILAR SPREAD OF SOLUTIONS THUS THERE IS
MEDIUM OVERALL CONFIDENCE IN THE JTWC TRACK FORECAST. MUCH OF THE
RELIABLE INTENSITY GUIDANCE INDICATES A FLAT OR SLOW WEAKENING
TREND OVER THE NEXT 24 HOURS WITH MORE SIGNIFICANT WEAKENING AFTER
TAU 24. HWRF, HOWEVER, SHOWS MODEST INTENSIFICATION WITH A
PEAK INTENSITY OF 95 TO 100 KNOTS WITHIN THE NEXT 48 HOURS. THE 
121800Z COAMPS-TC ENSEMBLE INDICATES A 20 TO 30 PERCENT PROBABILITY OF 
MODERATE INTENSIFICATION OVER THE NEXT 36 HOURS.

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