WDXS31 PGTW 020300 MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI// SUBJ/PROGNOSTIC REASONING FOR TROPICAL CYCLONE 14S (VERNON) WARNING NR 011// RMKS/ 1. FOR METEOROLOGISTS. 2. 6 HOUR SUMMARY AND ANALYSIS. SUMMARY: INITIAL POSITION: 17.6S 84.7E INITIAL INTENSITY: 45 KTS GEOGRAPHIC REFERENCE: 952 NM SOUTHEAST OF DIEGO GARCIA MOVEMENT PAST 6 HOURS: SOUTHWESTWARD AT 06 KTS SIGNIFICANT WAVE HEIGHT: 21 FEET SATELLITE ANALYSIS, INITIAL POSITION AND INTENSITY DISCUSSION: ANIMATED ENHANCED INFRARED (EIR) SATELLITE IMAGERY DEPICTS A SYSTEM WITH PERSISTENT, SYMMETRICAL CONVECTION OBSCURING THE LOW LEVEL CIRCULATION CENTER. THE OBSCURED LOW LEVEL FEATURES CAN ALSO BE OBSERVED IN A 012314Z SSMIS 91GHZ IMAGE, OF WHICH THE INITIAL POSITION IS BASED ON AND IS SUPPORTED BY THE PGTW POSITION FIX. THE INITIAL INTENSITY OF 45 KTS IS BASED ON THE PGTW DVORAK CURRENT INTENSITY ESTIMATE AND IS IN CLOSE AGREEMENT WITH ADT. INITIAL WIND RADII BASIS: PERSISTENCE CURRENT STEERING MECHANISM: SUBTROPICAL RIDGE TO THE EAST AGENCY DVORAK AND AUTOMATED FIXES: PGTW: T3.0 - 45 KTS FMEE: T3.5 - 55 KTS CIMSS ADT: 47 KTS AT 012115Z FORECASTER ASSESSMENT OF CURRENT ENVIRONMENT: MARGINALLY FAVORABLE VWS: 25-30 KTS SST: 28-29 CELSIUS OUTFLOW: STRONG POLEWARD OTHER FACTORS: MID-LEVEL DRY AIR ENTRAINMENT ANALYSIS CONFIDENCE: INITIAL POSITION: MEDIUM INITIAL INTENSITY: HIGH 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 14S WILL CONTINUE TO TRACK SOUTHWESTWARD ALONG THE WESTERN SIDE OF THE SUBTROPICAL RIDGE TO THE EAST. THE SYSTEM WILL CONTINUE THIS DIRECTION FOR THE MAJORITY OF THE FORECAST PERIOD, WITH A SLIGHT TURN SOUTH-SOUTHWEST AROUND TAU 48. THE CURRENT ENVIRONMENT IS EXPECTED TO PERSIST FOR THE NEXT 48 HOURS WITH TC 14S STRUGGLING TO INTENSIFY ABOVE 55 KTS DUE TO MID-LEVEL DRY AIR ENTRAINMENT AND STRONG VERTICAL WIND SHEAR. AROUND TAU 48, THE SYSTEM WILL CROSS INTO COOLER SEA SURFACE TEMPERATURES (LESS THAN 26C) AND BEGIN SUBTROPICAL TRANSITION. BY TAU 72, TC 14S SHOULD TRANSITION A SHALLOW WARM CORE, SUBTROPICAL SYSTEM WITH AN INTENSITY OF 45 KTS. MODEL DISCUSSION: NUMERICAL MODEL GUIDANCE IS IN TIGHT AGREEMENT IN REGARDS TO TRACK FORECAST WITH ONLY AN 80NM CROSS-TRACK SPREAD AT TAU 72. INTENSITY GUIDANCE IS ALSO IN GOOD AGREEMENT WITH MODELS INDICATING A PEAK INTENSITY OF 50-55 KTS AROUND TAU 24 FOLLOWING A GRADUAL WEAKENING FOR THE REMAINDER OF THE FORECAST PERIOD AS THE SYSTEM UNDERGOES SUBTROPICAL TRANSITION INTO COOLER WATERS. THIS LENDS TO OVERALL HIGH CONFIDENCE IN THE JTWC FORECAST TRACK AND FORECAST INTENSITY. FORECAST CONFIDENCE: TRACK 0 - 72 HR: HIGH INTENSITY 0 - 72 HR: HIGH// NNNN