WDIO31 PGTW 110300 MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI// SUBJ/PROGNOSTIC REASONING FOR TROPICAL CYCLONE 01B (ONE) WARNING NR 001// RMKS/ 1. FOR METEOROLOGISTS. 2. 6 HOUR SUMMARY AND ANALYSIS. SUMMARY: INITIAL POSITION: 11.1N 88.2E INITIAL INTENSITY: 35 KTS GEOGRAPHIC REFERENCE: 690 NM SOUTH OF KOLKATA, INDIA MOVEMENT PAST 6 HOURS: NORTHWESTWARD AT 03 KTS SIGNIFICANT WAVE HEIGHT: 21 FEET SATELLITE ANALYSIS, INITIAL POSITION AND INTENSITY DISCUSSION: ANIMATED MULTISPECTRAL SATELLITE IMAGERY (MSI) DEPICTS AN AREA OF CONVECTION BLOOMING OVER AN ASSESSED LOW LEVEL CIRCULATION CENTER (LLCC) WITH FEEDER BANDS IN THE NORTHERN AND SOUTHERN PERIPHERIES BECOMING BETTER DEFINED. ANALYSIS OF THE 102229Z SSMIS 91 GHZ PASS SHOWS FRAGMENTED LOW LEVEL BANDING FEATURES IN THE NORTHERN PERIPHERY WRAPPING INTO THE SLIGHTLY ELONGATED LLCC. IN ADDITION, THE SAME IMAGE SHOWS DEEP CONVECTION IN THE SOUTHWEST QUADRANT ATTEMPTING TO WRAP AROUND THE SYSTEM. TC 01B IS IN A FAVORABLE ENVIRONMENT FOR FURTHER TROPICAL DEVELOPMENT. THESE CONDITIONS ARE CHARACTERIZED BY GOOD POLEWARD AND EQUATORWARD OUTFLOW ALOFT, A STRONG 850 MB VORTICITY SIGNATURE, LOW (5-10 KTS) VERTICAL WIND SHEAR (VWS), AND VERY WARM (30-31 C) SEA SURFACE TEMPERATURES (SST). THE INITIAL POSITION IS PLACED WITH MEDIUM CONFIDENCE BASED ON MULTI-AGENCY FIXES, AS WELL AS THE AFOREMENTIONED MSI. THE INITIAL INTENSITY OF 35 KNOTS IS ASSESSED WITH MEDIUM CONFIDENCE BASED OFF A BLEND OF MULTI-AGENCY DVORAKS ESTIMATES. INITIAL WIND RADII BASIS: PARTIAL SCATTEROMETER DATA AND PARTIAL SMAP DATA CURRENT STEERING MECHANISM: TWO SUBTROPICAL RIDGES TO THE WEST AND EAST AGENCY DVORAK AND AUTOMATED FIXES: PGTW: T2.5 - 35 KTS KNES: T2.5 - 35 KTS DEMS: T2.5 - 35 KTS FORECASTER ASSESSMENT OF CURRENT ENVIRONMENT: FAVORABLE VWS: 5-10 KTS SST: 30-31 CELSIUS OUTFLOW: MODERATE POLEWARD AND EQUATORWARD ANALYSIS CONFIDENCE: INITIAL POSITION: MEDIUM INITIAL INTENSITY: MEDIUM INITIAL WIND RADII: LOW 3. FORECAST REASONING. SIGNIFICANT FORECAST CHANGES: THIS INITIAL PROGNOSTIC REASONING MESSAGE ESTABLISHES THE FORECAST PHILOSOPHY. FORECAST DISCUSSION: TC 01B HAS BEEN STRUGGLING WITH MID LEVEL DRY AIR ENTRAINMENT OVER THE PAST 36-48 HOURS, HOWEVER, IT APPEARS THE MID LEVELS HAVE OBTAINED ENOUGH MOISTURE TO FEED FURTHER TROPICAL DEVELOPMENT AT THIS TIME. AFTER SPENDING THE PAST SEVERAL HOURS CONSOLIDATING INTO A MORE DEFINED SYSTEM, TC 01B HAS SPENT THE PAST 6 HOURS IN A SOMEWHAT QUASI-STATIONARY POSTURE. BETWEEN TAUS 12 AND 24, TC 01B WILL TRACK NORTHWARD AS IT IS WEDGED BETWEEN TWO SUBTROPICAL RIDGES, ONE TO THE WEST AND ONE TO THE EAST. DURING THIS TIME, THE INTENSITY WILL STEADILY INCREASE TO 65 KNOTS BY TAU 24. BY TAU 36, THE STR TO THE EAST WILL BUILD INTO THE AREA SOUTHEAST OF THE SYSTEM, STEERING TC 01B IN A NORTHEASTWARD DIRECTION AS IT WILL CONTINUE TO INCREASE IN INTENSITY TO 80 KNOTS. BY TAUS 48 AND 72, TC 01B WILL PICK UP IN TRACK SPEED AND INTENSIFY TO 85 KNOTS AND 90 KNOTS RESPECTIVELY. LANDFALL WILL OCCUR ON OR ABOUT TAU 78 NEAR SITTWE, MYANMAR. AFTERWARDS, TC 01B WILL STEADILY DECREASE IN INTENSITY AND DISSIPATE DUE TO LAND INTERACTION THROUGH TAUS 96 AND 120. MODEL DISCUSSION: THE DETERMINISTIC AND ENSEMBLE MODELS ALL AGREE THAT TC 01B WILL CONTINUE TO INTENSIFY AS IT TRANSITS NORTHWARD, THEN NORTHEASTWARD AFTER TAU 24 BEFORE MAKING LANDFALL BY TAU 78, AND THEN DISSIPATE THROUGHOUT THE FORECAST PERIOD DUE TO LAND INTERACTION. AMONG THE JTWC FORECAST TRACK CONSENSUS MEMBERS, THERE IS A 65 NM SPREAD AT TAU 24 THAT SPREADS TO 121 NM BEFORE LANDFALL. DUE TO THE SPREAD, THE JTWC FORECAST TRACK IS PLACED WITH MEDIUM CONFIDENCE UP TO TAU 72, THEN LOW CONFIDENCE AFTERWARDS. THE INTENSITY CONSENSUS MEMBERS ARE ALSO IN AGREEMENT DISPLAYING A RAPIDLY INTENSIFYING SYSTEM BETWEEN TAUS 24 AND 60, THEN A SUDDEN DROP OFF AFTER TAU 78 WHEN THE SYSTEM MAKES LANDFALL. THE JTWC FORECAST INTENSITY IS SET WITH MEDIUM CONFIDENCE. FORECAST CONFIDENCE: TRACK 0 - 72 HR: MEDIUM TRACK 72-120 HR: LOW INTENSITY 0 - 72 HR: MEDIUM INTENSITY 72-120 HR: MEDIUM// NNNN