WDPN33 PGTW 190900 MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI// SUBJ/PROGNOSTIC REASONING FOR TROPICAL STORM 25W (NEOGURI) WARNING NR 004// RMKS/ 1. FOR METEOROLOGISTS. 2. 6 HOUR SUMMARY AND ANALYSIS. SUMMARY: INITIAL POSITION: 24.1N 160.3E INITIAL INTENSITY: 50 KTS GEOGRAPHIC REFERENCE: 1262 NM EAST-SOUTHEAST OF YOKOSUKA, JAPAN MOVEMENT PAST 6 HOURS: WEST-NORTHWESTWARD AT 10 KTS SIGNIFICANT WAVE HEIGHT: 18 FEET SATELLITE ANALYSIS, INITIAL POSITION AND INTENSITY DISCUSSION: ANIMATED MULTISPECTRAL SATELLITE IMAGERY (MSI) DEPICTS TROPICAL STORM 25W (NEOGURI) WITH CURVED CONVECTIVE BANDING BEGINNING TO ENCIRCLE THE OBSCURED LOW-LEVEL CIRCULATION CENTER (LLCC). A 190701Z WSFM 37 GHZ MICROWAVE IMAGE REVEALED A WELL-DEFINED MICROWAVE EYE FEATURE IN THE LOWER-LEVELS. ENVIRONMENTAL ANALYSIS INDICATES THAT 25W IS IN A FAVORABLE ENVIRONMENT CHARACTERIZED BY STRONG EQUATORWARD OUTFLOW ALOFT, LOW (5-10 KTS) VERTICAL WIND SHEAR, AND WARM (29-30 C) SEA SURFACE TEMPERATURES. THE INITIAL POSITION IS PLACED WITH HIGH CONFIDENCE BASED ON EXTRAPOLATION TO THE MENTIONED WSFM MICROWAVE IMAGE. THE INITIAL INTENSITY OF 50 KTS IS ASSESSED WITH LOW CONFIDENCE BASED ON A BLEND OF THE AGENCY DVORAK AND OBJECTIVE INTENSITY ESTIMATES LISTED BELOW. DECREASED UNCERTAINTY IS DUE TO THE STRONG APPEARANCE IN MICROWAVE IMAGERY, HINTING AT A POSSIBLE HIGHER INTENSITY THAN IS CURRENTLY ASSESSED. INITIAL WIND RADII BASIS: OBJECTIVE BEST TRACK CURRENT STEERING MECHANISM: SOUTHWESTERN PERIPHERY OF A SUBTROPICAL RIDGE CENTERED TO THE NORTHEAST AGENCY DVORAK AND AUTOMATED FIXES: PGTW: T3.5 - 55 KTS RJTD: T3.0 - 45 KTS RCTP: T3.5 - 55 KTS KNES: T3.5 - 55 KTS CIMSS SATCON: 49 KTS AT 190217Z CIMSS ADT: 47 KTS AT 190610Z CIMSS AIDT: 43 KTS AT 190610Z CIMSS D-MINT: 50 KTS AT 190256Z CIMSS D-PRINT: 55 KTS AT 190610Z FORECASTER ASSESSMENT OF CURRENT ENVIRONMENT: FAVORABLE VWS: 5-10 KTS SST: 29-30 CELSIUS OUTFLOW: STRONG EQUATORWARD ANALYSIS CONFIDENCE: INITIAL POSITION: HIGH INITIAL INTENSITY: LOW INITIAL WIND RADII: LOW 3. FORECAST REASONING. SIGNIFICANT FORECAST CHANGES: THERE ARE NO SIGNIFICANT CHANGES TO THE FORECAST FROM THE PREVIOUS WARNING. FORECAST DISCUSSION: 25W IS FORECAST TO TRACK NORTHWESTWARD, ALONG THE SOUTHWESTERN PERIPHERY OF THE SUBTROPICAL RIDGE THROUGH TAU 48. NEAR TAU 48, THE SYSTEM WILL BEGIN TO ROUND THE WESTERN EXTENT OF THE RIDGE, CHANGING THE TRAJECTORY NORTHWARD. A NORTHEASTWARD TRACK IS EXPECTED TO ENSUE FROM TAU 72 ONWARD AS THE VORTEX TRACKS ALONG THE NORTHWESTERN PERIPHERY OF THE RIDGE AND TRACKS POLEWARD. THERE CONTINUES TO BE UNCERTAINTY REGARDING THE RECURVE, THOUGH MODELS HAVE STARTED TO AGREE MORE ON A TRADITIONAL RECURVE SCENARIO. THERE IS A SECOND RIDGE THAT FOLLOWS BEHIND THE FIRST, WHICH COULD POTENTIALLY KEEP 25W FROM TRACKING FURTHER POLEWARD, AND INSTEAD, OUT WESTWARD. REGARDING INTENSITY, 25W IS FORECAST TO STEADILY INTENSIFY OVER THE NEXT 72 HOURS TO A PEAK OF 105 KTS BEFORE BEGINNING TO RECURVE. SEA SURFACE TEMPERATURES ARE EXPECTED TO REMAIN VERY WARM THROUGH THE FIRST 72 HOURS OF THE FORECAST, ALLOWING FOR THE INTENSIFICATION. AFTER TAU 72, COOLING SEA SURFACE TEMPERATURES AND INCREASING SHEAR WILL CAUSE 25W TO WEAKEN THROUGH THE REMAINDER OF THE FORECAST PERIOD. MODEL DISCUSSION: NUMERICAL MODEL TRACK GUIDANCE IS IN GOOD AGREEMENT THROUGH TAU 72 WITH A 145 NM CROSS-TRACK SPREAD AT TAU 72. AFTERWARD, MODELS GREATLY DIVERGE AND BIFURCATE. ECMWF, NAVGEM, AND GALWEM HAVE THE VORTEX MAKING A LOOP AND FAILING TO RECURVE. AI MODELS AND GFS DEPICT THE MORE TEXTBOOK RECURVE SCENARIO. THE JTWC TRACK FORECAST IS MORE IN LINE WITH THE AI MODELS AND GFS AFTER TAU 72 WITH VERY LOW CONFIDENCE. INTENSITY GUIDANCE IS IN POOR AGREEMENT WITH PEAK INTENSITIES RANGING FROM 85 KTS (GFS) TO 145 KTS (COAMPS-TC). ALL MODELS DO AGREE ON WEAKENING AFTER TAU 72 THOUGH. THE JTWC INTENSITY FORECAST IS CLOSE TO THE HAFS-A DEPICTION, WITH A PEAK OF 105 KTS BEFORE WEAKENING. OVERALL, THERE IS LOW CONFIDENCE IN THE JTWC INTENSITY FORECAST DUE TO THE LARGE SPREAD IN GUIDANCE. FORECAST CONFIDENCE: TRACK 00-72 HR: HIGH TRACK 72-120 HR: LOW INTENSITY 00-72 HR: LOW INTENSITY 72-120 HR: LOW// NNNN