WDIO31 PGTW 121500 MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI// SUBJ/PROGNOSTIC REASONING FOR TROPICAL CYCLONE 02A (BIPARJOY) WARNING NR 026// RMKS/ 1. FOR METEOROLOGISTS. 2. 6 HOUR SUMMARY AND ANALYSIS. SUMMARY: INITIAL POSITION: 19.9N 67.3E INITIAL INTENSITY: 85 KTS GEOGRAPHIC REFERENCE: 294 NM SOUTH OF KARACHI, PAKISTAN MOVEMENT PAST 6 HOURS: NORTH-NORTHWESTWARD AT 04 KTS SIGNIFICANT WAVE HEIGHT: 32 FEET SATELLITE ANALYSIS, INITIAL POSITION AND INTENSITY DISCUSSION: ANIMATED MULTISPECTRAL SATELLITE IMAGERY (MSI) DEPICTS A CENTRAL DENSE OVERCAST (CDO) CLOUD FEATURE THAT IS STRUGGLING TO MAINTAIN COVER OF THE LLCC. WHILE THE INNER CORE OF THE SYSTEM IS WELL COVERED, A LARGE WEDGE OF DRY AIR IS WRAPPING ITS WAY AROUND THE SOUTHERN PERIPHERY OF THE SYSTEM. A SUITE OF 121108Z SSMIS 37GHZ AND 91GHZ MICROWAVE IMAGERY INDICATES VERTICAL TILTING, REPRESENTED BY MISMATCHING LLCC AND ULCC LOCATIONS. THE INITIAL POSITION IS PLACED WITH MEDIUM CONFIDENCE BASED ON MSI AND SSMIS IMAGERY. 02A HAS PROGRESSED SEVERAL TIMES THROUGH A SINUSOIDAL TREND OF CONVECTIVE CONSOLIDATION AND CORRESPONDING SPIKE IN INTENSITY ONLY TO FIZZLE SIX HOURS LATER, RESULTING IN A DIP IN INTENSITY VALUES. WE FIND OURSELVES IN A LULL AFTER A SHORT-LIVED RECONSOLIDATION SEVERAL HOURS AGO. DVORAK FT VALUES HAVE DROPPED BACK TO T5.0 WHILE CI VALUES REMAIN INFLATED FROM THE LAST BRIEF SURGE. AUTOMATED INTENSITY ESTIMATES SUCH AS CIMSS ADT, D-PRINT AND D-MINT REMAIN CLOSE TO AND THEREFORE SUPPORTIVE OF THE JTWC INITIAL INTENSITY OF 85KTS. FOR THIS REASON THE INITIAL INTENSITY OF 85 KTS IS ASSESSED WITH MEDIUM CONFIDENCE. INITIAL WIND RADII BASIS: PERSISTENCE CURRENT STEERING MECHANISM: WESTERN PERIPHERY OF A DEEP-LAYER STR OVER INDIA. AGENCY DVORAK AND AUTOMATED FIXES: PGTW: T5.5 - 102 KTS KNES: T5.5 - 102 KTS DEMS: T5.0 - 90 KTS CIMSS SATCON: 94 KTS AT 120851Z CIMSS ADT: 82 KTS AT 120900Z FORECASTER ASSESSMENT OF CURRENT ENVIRONMENT: MARGINAL VWS: 20-25 KTS SST: 30-31 CELSIUS OUTFLOW: STRONG EQUATORWARD 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: 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 PERSISTENT SPREAD IN MODEL OUTPUTS FOLLOWING TAU 48 AS THE TIMING AND EXTENT OF THE NORTHEASTWARD 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. NOTWITHSTANDING NVGM, THE JTWC FORECAST TRACK IS PLACED WITH OVERALL MEDIUM CONFIDENCE. RELIABLE MODEL INTENSITY GUIDANCE REMAINS IN POOR AGREEMENT, WITH HWRF AND COMAPS-TC (NVGM VERSION) 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// NNNN