WDIO31 PGTW 120900
MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI//
SUBJ/PROGNOSTIC REASONING FOR TROPICAL CYCLONE 02A (BIPARJOY) WARNING 
NR 025//
RMKS/
1. FOR METEOROLOGISTS.
2. 6 HOUR SUMMARY AND ANALYSIS.

SUMMARY:
   INITIAL POSITION: 19.7N 67.5E
   INITIAL INTENSITY: 85 KTS
   GEOGRAPHIC REFERENCE: 307 NM SOUTH OF KARACHI, PAKISTAN
   MOVEMENT PAST 6 HOURS: NORTH-NORTHWESTWARD AT 04 KTS
   SIGNIFICANT WAVE HEIGHT: 36 FEET

SATELLITE ANALYSIS, INITIAL POSITION AND INTENSITY DISCUSSION:
ANIMATED MULTISPECTRAL SATELLITE IMAGERY (MSI) DEPICTS A SINGLE
TIGHTLY WRAPPING BAND OF CONVECTION ONCE AGAIN SURROUNDING THE
CIRCULATION AND FORMING A QUASI EYE FEATURE. THE OVERALL DENSITY OF
CONVECTIVE COVER IS FALLING AS MID-LEVEL DRY AIR ENTRAINMENT
INCREASES. A 120423Z AMSUB 89GHZ MICROWAVE IMAGE CONFIRMS WHAT IS
EVIDENT IN VISIBLE IMAGERY, THAT A SINGLE BAND OF DEEP CONVECTION
NOW OCCUPIES THE UPPER LEVEL CIRCULATION. THE INITIAL POSITION IS
PLACED WITH MEDIUM CONFIDENCE BASED ON MSI AND AMSUB IMAGERY. THE
INITIAL INTENSITY OF 85 KTS IS ASSESSED WITH HIGH CONFIDENCE BASED
ON AGENCY DVORAK INTENSITY ESTIMATES UNANIMOUSLY SHOWING T5.0 WHILE
AUTOMATED ESTIMATES SUCH AS CIMSS ADT, D-MINT AND D-PRINT ARE NOT
FAR BEHIND AT 75-82KTS.

INITIAL WIND RADII BASIS: PERSISTENCE 

CURRENT STEERING MECHANISM: WESTERN PERIPHERY OF A DEEP-LAYER STR
OVER INDIA.

AGENCY DVORAK AND AUTOMATED FIXES: 
   PGTW: T5.0 - 90 KTS
   KNES: T5.0 - 90 KTS
   DEMS: T5.0 - 90 KTS
   CIMSS ADT: 82 KTS AT 120600Z

FORECASTER ASSESSMENT OF CURRENT ENVIRONMENT: MARGINAL
   VWS: 20-25 KTS
   SST: 30-31 CELSIUS
   OUTFLOW: STRONG EQUATORWARD

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

3. FORECAST REASONING.

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

FORECAST DISCUSSION: TC 02A IS STILL PROGRESSING THROUGH A
CONVECTIVE WAXING AND WANING PHASE, THOUGH SIGNIFICANT
INTENSIFICATION IS LIKELY OUT OF REACH. AS THE SYSTEM PROGRESSES
POLEWARD, THE ENVIRONMENT WILL GRADUALLY BECOME MORE HOSTILE.
FAVORABLE UPPER-LEVEL OUTFLOW WILL BE REPLACED WITH SUBSIDENCE
ALOFT, VERTICAL WIND SHEAR VALUES REMAIN MODERATE AND DRY AIR
ENTRAINMENT WILL INUNDATE THE CIRCULATION. THESE FACTORS WILL
GRADUALLY WEAKEN THE CIRCULATION THROUGH TAU 48. AFTER TAU 48, THE
STR OVER SOUTHERN INDIA SHIFTS EQUATORWARD, ALLOWING THE SYSTEM TO
PASS NORTH OF IT. BY TAU 72, 02A WILL BEGIN TO INTERACT WITH THE
PAKISTAN-INDIA BOARDER AND AFTER MAKING LANDFALL SHORTLY
THEREAFTER, THE SYSTEM WILL RAPIDLY WEAKEN AS IT TRACK
NORTHEASTWARD, EVENTUALLY DISSIPATING BY TAU 120.

MODEL DISCUSSION: NUMERICAL MODELS ARE IN FAIR AGREEMENT THAT 02A
WILL TRACK NORTHWARD THROUGH TAU 48 AFTER WHICH THE SYSTEM WILL
TURN NORTHEASTWARD AND EVENTUALLY DISSIPATE OVER NORTHWESTERN
INDIA. THERE IS A SLIGHT SPREAD IN MODEL OUTPUTS FOLLOWING TAU 48
AS THE TIMING AND EXTENT OF THE TURN VARIES SLIGHTLY BETWEEN
MEMBERS. NVGM REMAINS IN ITS OWN WORLD AND PUSHES THE SYSTEM
NORTHWARD THROUGH THE FORECAST PERIOD DESPITE THE PESKY RIDGING IN
ITS WAY. DESPITE NVGM, THE JTWC FORECAST TRACK IS PLACED WITH
OVERALL MEDIUM CONFIDENCE. RELIABLE MODEL INTENSITY GUIDANCE
REMAINS IN POOR AGREEMENT, WITH HWRF RAPIDLY INTENSIFYING THE
SYSTEM THROUGH TAU 36 DESPITE THE AFOREMENTIONED DETERIORATING
ENVIRONMENT, WHILE THE REMAINING GUIDANCE WEAKENS THE SYSTEM
THROUGH THE FORECAST PERIOD. FOR THIS REASON THE JTWC INTENSITY
FORECAST IS PLACED WITH OVERALL LOW CONFIDENCE.

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