WDIO31 PGTW 130900
MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI//
SUBJ/PROGNOSTIC REASONING FOR TROPICAL CYCLONE 02A (BIPARJOY) WARNING 
NR 029//
RMKS/
1. FOR METEOROLOGISTS.
2. 6 HOUR SUMMARY AND ANALYSIS.

SUMMARY:
   INITIAL POSITION: 21.1N 66.7E
   INITIAL INTENSITY: 90 KTS
   GEOGRAPHIC REFERENCE: 223 NM SOUTH OF KARACHI, PAKISTAN
   MOVEMENT PAST 6 HOURS: NORTHWESTWARD AT 05 KTS
   SIGNIFICANT WAVE HEIGHT: 32 FEET

SATELLITE ANALYSIS, INITIAL POSITION AND INTENSITY DISCUSSION:
ANIMATED MULTISPECTRAL SATELLITE IMAGERY (MSI) DEPICT AN
ASYMMETRICAL SYSTEM THAT IS BATTLING PRESSURE IN THE NORTHEAST
QUADRANT. IN ADDITION, SPIRAL BANDS OF DEEP CONVECTION WRAPPING
INTO AN ASSESSED LOW LEVEL CIRCULATION CENTER (LLCC). ANALYSIS OF
THE 130207Z SSMIS 91 GHZ IMAGE REVEALS THE DEEPEST SPOTS OF
CONVECTION IS LOCATED IN THE SOUTHWEST QUADRANT AND THE NORTHEAST
QUADRANT ALONG THE NORTHWEST SHORE OF INDIA. MOREOVER, THE SAME
PASS INDICATES A SMALL MICROWAVE EYE IS PRESENT. TC BIPARJOY IS IN
A MARGINALLY FAVORABLE ENVIRONMENT FOR FURTHER TROPICAL ACTIVITY.
THESE CONDITIONS ARE CHARACTERIZED BY MODERATE WESTWARD OUTFLOW
ALOFT, A STRONG 850 MB VORTICITY SIGNATURE, VERY WARM (30-31 C) SEA
SURFACE TEMPERATURES (SST), OFFSET BY MARGINAL (20-25 KTS) VERTICAL
WIND SHEAR (VWS). THE INITIAL POSITION IS PLACED WITH MEDIUM
CONFIDENCE BASED ON MULTI-AGENCY FIXES, ALONG WITH THE
AFOREMENTIONED MSI AND EXTRAPOLATION FROM THE SSMIS IMAGERY. THE
INITIAL INTENSITY OF 90 KNOTS IS ASSESSED WITH MEDIUM CONFIDENCE
FAVORING THE PGTW AND KNES DVORAK ESTIMATES. HOWEVER, IT SHOULD BE
NOTED THAT THE AUTOMATED DVORAK ESTIMATES HAVE BEEN ON THE DOWNWARD
TREND OVER THE PAST 6 HOURS.

INITIAL WIND RADII BASIS: PERSISTENCE 

CURRENT STEERING MECHANISM: SUBTROPICAL RIDGE (STR) LOCATED TO THE
EAST

AGENCY DVORAK AND AUTOMATED FIXES: 
   PGTW: T5.0 - 90 KTS
   KNES: T5.0 - 90 KTS
   CIMSS SATCON: 87 KTS AT 130250Z
   CIMSS ADT: 82 KTS AT 130630Z

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

ANALYSIS CONFIDENCE:
   INITIAL POSITION: MEDIUM
   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 (BIPARJOY) CONTINUES TO BATTLE ITS
ENVIRONMENT AS IT RIDES THE WESTERN EDGE OF THE STR TO THE EAST.
THROUGH TAU 12, THE SYSTEM WILL MAINTAIN ITS INTENSITY OF 90 KNOTS
AS IT BEGINS TO MAKE THE TURN NORTHWARD, ROUNDING THE STR AXIS.
THROUGH TAUS 24 AND 36, TC 02A WILL BE ON A NORTHEASTWARD
TRAJECTORY AND WILL STEADILY WEAKEN TO 70 KNOTS PRIOR TO LANDFALL
NEAR THE INDIA-PAKISTAN BORDER DUE TO LAND INTERACTION. THROUGH
TAUS 72 AND 96, TC 02A WILL DISSIPATE INLAND OVER NORTHERN INDIA.

MODEL DISCUSSION: THE DETERMINISTIC AND ENSEMBLE MODELS ARE ALL IN
TIGHT AGREEMENT THAT TC BIPARJOY WILL TRACK NORTHWARD THROUGH TAU
12, THEN MAKE THE TURN NORTHEASTWARD AFTERWARDS RIDING THE
NORTHWESTERN PERIPHERY OF THE STR TO THE EAST. NAVGEM IS THE
OUTLIER SHOWING AN UNLIKELY SCENARIO OF THE SYSTEM HEADING DUE
NORTH IN THE NEAR FUTURE. DUE TO THIS SPORADIC BEHAVIOR, THE JTWC
FORECAST TRACK IS SET TO THE RIGHT OF CONSENSUS WITH HIGH
CONFIDENCE. THE JTWC INTENSITY CONSENSUS MEMBERS ALL AGREE WITH A
DECAYING TREND THROUGH AFTER TAU 12 AS THE SYSTEM TRANSITS CLOSER
TO LAND. THE JTWC INTENSITY FORECAST IS SET WITH MEDIUM CONFIDENCE
THROUGHOUT THE FORECAST PERIOD.

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