WDIO31 PGTW 070900 MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI// SUBJ/PROGNOSTIC REASONING FOR TROPICAL CYCLONE 02A (BIPARJOY) WARNING NR 005// RMKS/ 1. FOR METEOROLOGISTS. 2. 6 HOUR SUMMARY AND ANALYSIS. SUMMARY: INITIAL POSITION: 12.9N 66.4E INITIAL INTENSITY: 80 KTS GEOGRAPHIC REFERENCE: 627 NM SOUTHEAST OF MASIRAH ISLAND MOVEMENT PAST 6 HOURS: NORTH-NORTHEASTWARD AT 04 KTS SIGNIFICANT WAVE HEIGHT: 26 FEET SATELLITE ANALYSIS, INITIAL POSITION AND INTENSITY DISCUSSION: ANIMATED MULTISPECTRAL SATELLITE IMAGERY (MSI) DEPICTS DEEP FLARING CONVECTION IN THE CORE OF THE CIRCULATION THAT HAS BEEN STRUGGLING TO PERSIST AND OUTLAST MODERATE VERTICAL WIND SHEAR AND A DRY AIR MASS TO THE NORTH. A RECENT PARTIAL 070439Z ASCAT-B SCATTEROMETRY PASS REVEALS IMPROVED SYMMETRY OF THE WIND FIELD IN THE EASTERN SEMICIRCLE. A 070125Z SMAP MICROWAVE RADIOMETRY PASS REVEALS A LARGE FIELD OF 79-80KT WINDS WRAPPING THE SOUTHERN PORTION OF THE CIRCULATION. THE INITIAL POSITION IS PLACED WITH MEDIUM CONFIDENCE BASED ON MSI AND PARTIAL SCATTEROMETRY DATA. THE INITIAL INTENSITY OF 80 KTS IS ASSESSED WITH MEDIUM CONFIDENCE BASED ON PGTW DVORAK AND CIMSS ADT INTENSITY ESTIMATES OF 74-77KTS AS WELL AS THE SMAP SCALAR WINDS PRODUCT WHICH SHOWED 79-80KTS. INITIAL WIND RADII BASIS: PARTIAL SCATTEROMETER DATA CURRENT STEERING MECHANISM: NEAR-EQUATORIAL RIDGE (NER) TO THE SOUTH AND STR TO THE EAST. AGENCY DVORAK AND AUTOMATED FIXES: PGTW: T4.5 - 77 KTS KNES: T4.0 - 65 KTS CIMSS ADT: 74 KTS AT 070600Z FORECASTER ASSESSMENT OF CURRENT ENVIRONMENT: FAVORABLE VWS: 20-25 KTS SST: 30-31 CELSIUS OUTFLOW: MODERATE POLEWARD AND EQUATORWARD 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) IS FORECAST TO TRACK GENERALLY NORTH-NORTHWESTWARD THROUGH THE FORECAST PERIOD UNDER THE STEERING INFLUENCE OF A NER TO THE SOUTH AND STR TO THE EAST. AS THE REMNANTS OF A BLOCKING RIDGE TO THE NORTHWEST IS BROKEN DOWN THROUGH TAU 24, WARM SEA SURFACE TEMPERATURES AND VIGOROUS OUTFLOW ALOFT WILL PROVIDE THE FINAL OPPORTUNITY FOR 02A TO SURGE TO A PEAK INTENSITY NEAR 100KTS. THIS SURGE IS CONTINGENT ON WHETHER THE SYSTEM CAN CONSOLIDATE AND MAINTAIN CONVECTIVE COVER. AS THE SYSTEM PROGRESSES FURTHER INTO THE ARABIAN SEA, VERTICAL WIND SHEAR (VWS) AND DRY AIR ENTRAINMENT WILL SLOWLY ERODE THE CIRCULATION AS IT CONTINUES POLEWARD THROUGH THE FORECAST PERIOD. MODEL DISCUSSION: NUMERICAL MODELS ARE IN FAIR AGREEMENT WITH A PERSISTENT SPREADING IN OUTPUT THROUGH THE FORECAST PERIOD. THIS COUPLED WITH MODERATE RUN TO RUN VARIABILITY AND THE RESULT IS OVERALL MEDIUM FORECAST TRACK CONFIDENCE. RELIABLE MODEL INTENSITY GUIDANCE IS IN POOR AGREEMENT WITH HWRF AND GFS IMMEDIATELY WEAKENING THE SYSTEM WHILE COAMPS-TC CONTINUES THE INTENSIFICATION TREND AND THE REMAINING MEMBERS ARE DOWN THE MIDDLE. 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