WDXS31 PGTW 092100 MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI// SUBJ/PROGNOSTIC REASONING FOR TROPICAL CYCLONE 19S (GOMBE) WARNING NR 005// RMKS/ 1. FOR METEOROLOGISTS. 2. 6 HOUR SUMMARY AND ANALYSIS. SUMMARY: INITIAL POSITION: 15.3S 44.3E INITIAL INTENSITY: 60 KTS GEOGRAPHIC REFERENCE: 283 NM NORTHWEST OF ANTANANARIVO, MADAGASCAR MOVEMENT PAST 6 HOURS: WEST-SOUTHWESTWARD AT 09 KTS SIGNIFICANT WAVE HEIGHT: 16 FEET SATELLITE ANALYSIS, INITIAL POSITION AND INTENSITY DISCUSSION: TC 19S HAS CONTINUED TO CONSOLIDATE QUICKLY AS IT TRACKS AWAY FROM MADAGASCAR WITH VERY FAVORABLE ENVIRONMENTAL CONDITIONS CHARACTERIZED BY NEAR-RADIAL OUTFLOW, LOW VERTICAL WIND SHEAR, WARM SST AND FAVORABLE OCEAN HEAT CONTENT VALUES. ANIMATED ENHANCED INFRARED (EIR) SATELLITE IMAGERY DEPICTS IMPROVED DEEP CONVECTIVE BANDING WRAPPING TIGHTLY INTO A DEFINED LOW-LEVEL CIRCULATION CENTER (LLCC). A 091550Z SSMIS 91GHZ MICROWAVE IMAGE SHOWS FRAGMENTED OUTER BANDING, HOWEVER, CORE CONVECTION IS WELL-ORGANIZED WITH TIGHTLY CURVED DEEP CONVECTIVE BANDING WRAPPING INTO THE LLCC. THE INITIAL POSITION IS PLACED WITH HIGH CONFIDENCE BASED ON A FORTUITOUS 091911Z ASCAT-B IMAGE, WHICH REVEALS A WELL-DEFINED CENTER WITH 40-45 KNOT MAXIMUM WINDS. DVORAK ESTIMATES, HOWEVER, HAVE INCREASED SIGNIFICANTLY AND NOW RANGE FROM T3.5 TO T4.0 (55-65 KNOTS). ADT OBJECTIVE ESTIMATES ARE SLIGHTLY LOWER AND RANGE FROM 3.0-3.4 (45-55 KNOTS). THE INITIAL INTENSITY OF 60 KTS IS ASSESSED WITH MEDIUM CONFIDENCE BASED ON AN AVERAGE OF THE DVORAK ESTIMATES CONSISTENT WITH THE OVERALL CONVECTIVE STRUCTURE. INITIAL WIND RADII BASIS: SCATTEROMETER DATA CURRENT STEERING MECHANISM: DEEP-LAYERED SUBTROPICAL RIDGE (STR) ENTRENCHED TO THE SOUTH. AGENCY DVORAK AND AUTOMATED FIXES: PGTW: T4.0 - 65 KTS FMEE: T3.5 - 55 KTS CIMSS SATCON: 48 KTS AT 091550Z CIMSS ADT: 45 KTS AT 091815Z FORECASTER ASSESSMENT OF CURRENT ENVIRONMENT: HIGHLY FAVORABLE VWS: 5-10 KTS SST: 29-30 CELSIUS OUTFLOW: MODERATE RADIAL ANALYSIS CONFIDENCE: INITIAL POSITION: HIGH INITIAL INTENSITY: MEDIUM INITIAL WIND RADII: MEDIUM 3. FORECAST REASONING. SIGNIFICANT FORECAST CHANGES: BASED ON THE SIGNIFICANT IMPROVEMENT IN THE SYSTEM'S ORGANIZATION, THE PEAK INTENSITY HAS BEEN SHIFTED TO TAU 24 AND INCREASED TO 100 KNOTS. FORECAST DISCUSSION: TC 19S HAS ACCELERATED SLIGHTLY AS IT TRACKS UNDER THE STEERING INFLUENCE OF THE DEEP-LAYERED STR TO THE SOUTH, AND IS EXPECTED TO TRACK GENERALLY WESTWARD OVER THE NEXT 72 HOURS. VERY FAVORABLE ENVIRONMENTAL CONDITIONS SUPPORT RAPID INTENSIFICATION THROUGH LANDFALL NEAR TAU 30 OVER THE EASTERN COAST OF MOZAMBIQUE WITH A PEAK INTENSITY NEAR 100 KNOTS AT TAU 24 TO TAU 30. NEAR TAU 72, THE STEERING RIDGE IS EXPECTED TO WEAKEN WITH THE APPROACH OF A DEEP MIDLATITUDE TROUGH AND, CONSEQUENTLY, TC 19S SHOULD SLOW OVER MOZAMBIQUE WHICH WILL LIKELY LEAD TO SIGNIFICANT RAINFALL AND MAJOR FLOODING AS THE SYSTEM STALLS. TC 19S WILL DISSIPATE QUICKLY OVERLAND, HOWEVER, AFTER TAU 72, THE STR WILL RE-ORIENT NORTH-SOUTH AND WILL PRODUCE A SOUTHWARD TO SOUTH-SOUTHEASTWARD TRACK WITH THE SYSTEM REMNANTS EXPECTED TO RE-EMERGE OVER THE MOZAMBIQUE CHANNEL. THERE IS A LOW PROBABILITY THAT THE SYSTEM MAY RE-DEVELOP INTO A WEAK TROPICAL CYCLONE. MODEL DISCUSSION: NUMERICAL MODEL GUIDANCE SUPPORTS THE JTWC FORECAST TRACK WITH HIGH CONFIDENCE THROUGH TAU 72 WITH A 55NM SPREAD IN SOLUTIONS AT TAU 36 AND 70NM SPREAD AT TAU 72. AFTER TAU 72, MODEL GUIDANCE DIVERGES WITH MEDIUM OVERALL TRACK CONFIDENCE DUE TO THE WEAKENING STR AND INTERACTION WITH THE MIDLATITUDE TROUGH. RELIABLE INTENSITY GUIDANCE SUPPORTS THE JTWC FORECAST PHILOSOPHY WITH HWRF, COAMPS-TC (BOTH THE GFS AND NAVGEM VERSIONS) INDICATING A PEAK NEAR 100 KNOTS BY TAU 24 TO TAU 30. ADDITIONALLY, RAPID INTENSIFICATION AIDS HAVE TRIGGERED SUPPORTING THE INCREASING PROBABILITY OF RAPID INTENSIFICATION (RI) OCCURRING WITHIN THE NEXT 30 HOURS. THE JTWC INTENSITY FORECAST IS POSITIONED ABOVE THE JTWC INTENSITY CONSENSUS (ICNW). THE LATEST COAMPS-TC ENSEMBLE GUIDANCE INDICATES A 50 TO 60 PERCENT PROBABILITY OF RI OCCURRING WITHIN THE NEXT 36 HOURS, WHICH FURTHER BOLSTERS THE JTWC INTENSITY FORECAST. FORECAST CONFIDENCE: TRACK 0 - 72 HR: HIGH TRACK 72-120 HR: MEDIUM INTENSITY 0 - 72 HR: MEDIUM INTENSITY 72-120 HR: MEDIUM FORECASTER: BARLOW// NNNN