WDXS31 PGTW 110300 MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI// SUBJ/PROGNOSTIC REASONING FOR TROPICAL CYCLONE 19S (GOMBE) WARNING NR 010// RMKS/ 1. FOR METEOROLOGISTS. 2. 6 HOUR SUMMARY AND ANALYSIS. SUMMARY: INITIAL POSITION: 15.5S 40.7E INITIAL INTENSITY: 100 KTS GEOGRAPHIC REFERENCE: 403 NM NORTH OF EUROPA ISLAND MOVEMENT PAST 6 HOURS: WEST-NORTHWESTWARD AT 07 KTS SIGNIFICANT WAVE HEIGHT: 30 FEET SATELLITE ANALYSIS, INITIAL POSITION AND INTENSITY DISCUSSION: ANIMATED ENHANCED INFRARED (EIR) SATELLITE IMAGERY DEPICTS FORMATION OF A 22 NM EYE SURROUNDED BY INTENSE, DEEP CONVECTIVE BANDING. THE SYSTEM HAS TRACKED A BIT FARTHER EQUATORWARD THAN PREVIOUSLY PREDICTED, AND IS QUICKLY APPROACHING LANDFALL SOUTH OF NACALA, MOZAMBIQUE. THE INITIAL POSITION IS PLACED WITH HIGH CONFIDENCE BASED ON PGTW AND FMEE SATELLITE EYE FIXES. THE INTENSITY IS CONSISTENT WITH DVORAK INTENSITY ESTIMATES FROM THE SAME REPORTING AGENCIES, AS WELL AS CIMSS AIDT VALUES AROUND 100 KNOTS. INITIAL WIND RADII BASIS: OBJECTIVE BEST TRACK CURRENT STEERING MECHANISM: DEEP-LAYER SUBTROPICAL RIDGE TO THE SOUTH AGENCY DVORAK AND AUTOMATED FIXES: PGTW: T5.5 - 102 KTS FMEE: T5.5 - 102 KTS CIMSS SATCON: 88 KTS AT 102226Z FORECASTER ASSESSMENT OF CURRENT ENVIRONMENT: HIGHLY FAVORABLE VWS: 0-5 KTS SST: 28-29 CELSIUS OUTFLOW: STRONG WESTWARD ANALYSIS CONFIDENCE: INITIAL POSITION: HIGH INITIAL INTENSITY: HIGH INITIAL WIND RADII: MEDIUM 3. FORECAST REASONING. SIGNIFICANT FORECAST CHANGES: THE NEAR TO MEDIUM RANGE FORECAST TRACK HAS SHIFTED A BIT EQUATORWARD CONSISTENT WITH RECENT STORM MOTION, AND EXTENDED FORECAST TRACK SPEEDS HAVE BEEN REDUCED IN ANTICIPATION OF A WEAKER STEERING ENVIRONMENT. HOWEVER, THERE ARE NO MAJOR CHANGES TO THE OVERALL FORECAST PHILOSOPHY. FORECAST DISCUSSION: TC 19S WILL MAKE LANDFALL SOUTH OF NACALA, MOZAMBIQUE IMMINENTLY AND PROGRESS INLAND OVER THE NEXT SIX HOURS. GENERALLY WESTWARD MOTION WITH DISSIPATION BELOW 35 KNOTS IS EXPECTED DURING THE FIRST 36 HOURS OF THE FORECAST PERIOD UNDER THE CONTINUED STEERING INFLUENCE OF THE SUBTROPICAL RIDGE TO THE SOUTH. THEREAFTER, A WEAKNESS IS EXPECTED TO DEVELOP IN THE STEERING RIDGE TO THE SOUTH WITH SIMULTANEOUS BUILDING OF A MERIDIONALLY-ORIENTED RIDGE TO THE EAST OF THE SYSTEM. RIDGING TO THE EAST WILL EVENTUALLY BECOME THE PREDOMINANT STEERING MECHANISM AND TURN 19S TOWARD A POLEWARD TO SOUTHEASTWARD TRAJECTORY. THE REMNANT CIRCULATION OF 19S IS STILL EXPECTED TO REEMERGE OVER THE MOZAMBIQUE CHANNEL AFTER TAU 72, CONSOLIDATE AND REINTENSIFY UNDER THE INFLUENCE OF A WARM SEA SURFACE AND FAVORABLE UPPER-LEVEL SUPPORT. THERE IS A SMALLER PROBABILITY THAT 19S WILL EITHER DISSIPATE FULLY AND REMAIN OVER LAND OR REEMERGE OVER THE MOZAMBIQUE CHANNEL TOO WEAK OF A CIRCULATION TO RECONSOLIDATE. HOWEVER, THIS ALTERNATIVE OUTCOME APPEARS UNLIKELY AT THIS TIME, WITH THE MAJORITY OF AVAILABLE MODEL GUIDANCE SUPPORTING THE PRIMARY FORECAST SCENARIO OR REINTENSIFICATION. IN THE EXTENDED PERIOD, A SLOWDOWN IN FORWARD TRACK SPEEDS OVER THE CENTRAL MOZAMBIQUE CHANNEL IS POSSIBLE AS THE SYSTEM ENTERS AN ENVIRONMENT WITH COMPETING STEERING INFLUENCES. MODEL DISCUSSION: THE LATEST GUIDANCE PACKAGE HAS SHIFTED SLIGHTLY WESTWARD AND SLOWER THAN THE PREVIOUS RUN, SUGGESTING THAT THE CIRCULATION MAY REMAIN OVER LAND SIX TO TWELVE HOURS LONGER THAN PREVIOUSLY ANTICIPATED. THE NAVGEM AND GALWEM OUTLIER SOLUTIONS DEPICT TRACKS REMAINING OVER LAND, WITH NO REDEVELOPMENT. HOWEVER, THE REMAINING MODELS INCLUDING THE UK MET OFFICE, ECMWF AND NCEP DETERMINISTIC AND ENSEMBLE SOLUTIONS SUPPORT THE PRIMARY FORECAST SCENARIO OF A WESTWARD TRACK INTO MOZAMBIQUE FOLLOWED BY A POLEWARD TO SOUTHEASTWARD TURN AND REEMERGENCE INTO THE MOZAMBIQUE CHANNEL AFTER TAU 72. THE CURRENT JTWC FORECAST TRACK IS CONSISTENT WITH THE MAJORITY GROUPING OF MODELS AND PREVIOUS FORECAST TRACKS, WITH MEDIUM CONFIDENCE THROUGH TAU 72 AND LOW CONFIDENCE DUE THE POSSIBILITY OF AN ALTERNATE SCENARIO IN THE EXTENDED PERIOD. INTENSITY FORECAST MODELS ARE IN GOOD AGREEMENT DURING THE UPCOMING OVER-LAND WEAKENING PERIOD, LENDING HIGH CONFIDENCE TO THE INITIAL PORTION OF THE FORECAST. WITH THE SMALL POSSIBILITY OF DISSIPATION OF THE CIRCULATION OVER LAND STILL IN PLAY, CONFIDENCE IN THE EXTENDED INTENSITY FORECAST IS LOW. FORECAST CONFIDENCE: TRACK 0 - 72 HR: MEDIUM TRACK 72-120 HR: LOW INTENSITY 0 - 72 HR: HIGH INTENSITY 72-120 HR: LOW// NNNN