WDPN31 PGTW 260300 MSGID/GENADMIN/NAVMARFCSTCEN PEARL HARBOR HI/JTWC// SUBJ/PROGNOSTIC REASONING FOR TYPHOON 19W WARNING NR 14// RMKS/ 1. FOR METEOROLOGISTS. 2. 12 HOUR SUMMARY AND ANALYSIS. A. THE SYSTEM WAS UPGRADED TO SUPER TYPHOON (STY) STRENGTH BASED ON DVORAK INTENSITY ESTIMATES OF 6.5 (127 KNOTS) TO 7.0 (140 KNOTS). ANIMATED MULTISPECTRAL SATELLITE IMAGERY AND A 261953Z TMI IMAGE DEPICTED A ROUND 28 NM EYE WITH AN INTENSE, SYMMETRIC CORE OF DEEP CONVECTION AND EXCELLENT CONVECTIVE BANDING OVER ALL QUADRANTS. THE PRIMARY MODELS HAVE SHOWN INCREASING UNCERTAINTY AFTER TAU 48 WITH GREATER SPREAD IN THE MODEL TRACKER SOLUTIONS. B. THE LATEST 500 MB ANALYSIS DEPICTS A POLEWARD ORIENTED SUB- TROPICAL RIDGE (STR) EAST OF THE SYSTEM, AND AN EAST-WEST ORIENTED STR NORTH OF TAIWAN, EXTENDING WESTWARD INTO CENTRAL CHINA. DROP- SONDE DATA FROM THE TAIWAN DOTSTAR AIRCRAFT SUPPORTS THE CURRENT NORTHWESTWARD TRACK WITH THE DEEP LAYER MEAN FLOW OF 115/20 AT 24.8N 126.6E, APPROXIMATELY 300 NM NORTH OF THE CENTER. ANIMATED WATER VAPOR IMAGERY INDICATES EXCELLENT RADIAL OUTFLOW WITH EQUATORWARD OUTFLOW ENHANCED BY A STRONG HIGH EQUATORWARD OF AUSTRALIA AND POLEWARD OUTFLOW ENHANCED BY MIDLATITUDE WESTERLIES. THE CURRENT POSITION IS BASED ON THE VISIBLE EYE FIX. THERE IS HIGH CONFIDENCE IN THIS POSITION AS WELL AS SINUSOIDAL MOTION (EYE WOBBLE) OVER THE PAST 12 HOURS. THE CURRENT INTENSITY IS BASED ON AN AVERAGE OF THE AFOREMENTIONED DVORAK ESTIMATES. 3. FORECAST REASONING. A. THE EXTENDED FORECAST WAS ADJUSTED SLIGHTLY TO REFLECT A RE- CURVE OVER EASTERN CHINA. THE SYSTEM WAS UPGRADED TO STY STATUS AND THE INITIAL INTENSITY FORECASTS WERE ADJUSTED SLIGHTLY HIGHER THROUGH TAU 48. B. STY 19W IS FORECAST TO CONTINUE TRACKING NORTHWESTWARD THROUGH TAU 36 UNDER THE STEERING INFLUENCE OF THE MID-LEVEL STR POSITIONED EAST AND NORTHEAST OF THE SYSTEM. NEAR TAU 48, STY 19W SHOULD TRACK MORE WESTNORTHWESTWARD AS IT MOVES UNDER THE SHORT- TERM STEERING INFLUENCE OF THE STR NORTH OF TAIWAN. THIS RIDGE IS WEAK AND IS FORECAST TO FURTHER ERODE, ALLOWING STY 19W TO RE- CURVE. THE CURRENT FORECAST IS HEDGED CLOSER TO THE JGSM/UK MET SOLUTION AND DOES NOT FAVOR THE SHARP RE-CURVE INDICATED BY TC-LAPS AND WBAR. ANALYSIS OF THE MODEL FIELDS INDICATES A WEAK MIDLATITUDE SHORTWAVE TROUGH WHICH DOESN'T SUPPORT A SHARP RECURVATURE. STY 19W IS FORECAST TO SLOWLY WEAKEN AS IT APPROACHES TAIWAN DUE TO THE TRACK OVER SLIGHTLY COOLER SST AND LOWER OCEAN HEAT CONTENT. THE SYSTEM WILL WEAKEN SIGNIFICANTLY AS IT CROSSES TAIWAN. THE AVAILABLE MODEL TRACKERS ARE IN POOR AGREEMENT AFTER TAU 48 WITH TWO DISTINCT CLUSTERS. THE UK MET OFFICE, JGSM AND GFDN TRACK THE SYSTEM NORTHWESTWARD INTO CHINA WITHOUT RE-CURVING IT. THE GFS, NOGAPS, TC-LAPS, WBAR AND ECMWF RE-CURVE THE SYSTEM EAST OF SHANGHAI, CHINA. HOWEVER, THE MODEL SOLUTIONS ARE PROBLEMATIC IN THAT THEY ARE WEAKENING THE SYSTEM TOO RAPIDLY AND MERGING THE LOW WITH MIDLATITUDE LOWS. C. IN THE EXTENDED PERIOD, THE SYSTEM IS FORECAST TO CONTINUE TRACKING INLAND AND IS FORECAST TO START RE-CURVING AS WELL AS EXTRA- TROPICAL TRANSITION (ETT) AS IT INTERACTS WITH A WEAK BAROCLINIC ZONE. HOWEVER, THE SYSTEM IS EXPECTED TO DISSIPATE PRIOR TO COMPLET- ING ETT. FORECAST TEAM: DELTA // NNNN