MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI// SUBJ/PROGNOSTIC REASONING FOR TYPHOON 19W (MITAG) WARNING NR 011// RMKS/ 1. FOR METEOROLOGISTS. 2. 6 HOUR SUMMARY AND ANALYSIS. TYPHOON (TY) 19W (MITAG), LOCATED APPROXIMATELY 394 NM SOUTHWEST OF KADENA AB, HAS TRACKED NORTHWESTWARD AT 15 KNOTS (KTS) OVER THE PAST SIX HOURS. ANIMATED ENHANCED INFRARED SATELLITE IMAGERY (EIR) SHOWS A POCKET OF DEEP CONVECTION OVER THE LOW LEVEL CIRCULATION CENTER (LLCC) WITH A MOAT OF DRIER AIR DECREASING THE CONVECTION IN THE NEAR-CENTER FEEDER BANDS. THERE ARE LARGE AREAS OF DEEP CONVECTION IN FEEDER BANDS 150-200 NM TO THE NORTH AND SOUTHEAST OF THE LLCC. BASED ON THE MOTION OF THE FEEDER BANDS NEAR THE DEEP CENTRAL CONVECTION, THERE IS GOOD CONFIDENCE IN THE INITIAL POSITION. THE INITIAL INTENSITY IS CONSISTENT WITH PGTW AND RJTD DVORAK INTENSITY ESTIMATES OF T4.0 (65 KTS). OVER THE PAST SIX HOURS, THE DRY AIR ENTRAINING INTO THE SYSTEM HAS OFFSET LOW (5-10 KT) VERTICAL WIND SHEAR (VWS), GOOD EQUATORWARD AND POLEWARD OUTFLOW, AND WARM (28-29 CELSIUS) SEA SURFACE TEMPERATURE (SST) TO LIMIT INTENSIFICATION. TY 19W IS TRACKING AROUND THE SOUTHWESTERN PERIPHERY OF A SUBTROPICAL RIDGE (STR). 3. FORECAST REASONING. A. THERE IS NO CHANGE TO THE FORECAST PHILOSOPHY SINCE THE PREVIOUS PROGNOSTIC REASONING MESSAGE. B. BY TAU 36, TY 19W WILL CREST THE STR AXIS AND GRADUALLY BEGIN TURNING TOWARD A NORTHEASTWARD TRACK. THE ENVIRONMENT WILL REMAIN MARGINALLY FAVORABLE AND SUPPORT SLIGHT INTENSIFICATION THROUGH TAU 36. AFTER TAU 36, LAND INTERACTION WITH COASTAL CHINA, COOL SST, AND HIGH VWS SHOULD GRADUALLY WEAKEN THE SYSTEM. THERE IS HIGH UNCERTAINTY IN THE NEAR-TERM INTENSITY FORECAST BECAUSE OF THE PROXIMITY OF THE TRACK TO CHINA AND TAIWAN. DESPITE TWO SLIGHT EASTERN OUTLIERS (NAVGEM AND JGSM), SPREAD IN THE TRACK GUIDANCE IS ONLY 130 NM AT TAU 72, LENDING TO GOOD CONFIDENCE IN THIS PORTION OF THE JTWC TRACK FORECAST. C. AFTER TAU 72, TY 19W WILL GRADUALLY TURN MORE WESTWARD AS IT BECOMES EMBEDDED IN THE MID-LATITUDE WESTERLIES AND STARTS EXTRATROPICAL TRANSITION (ETT). PRIOR TO TAU 120, TY 19W WILL HAVE COMPLETELY TRANSITIONED INTO A COLD-CORE LOW AS IT APPROACHES JAPAN. THE CURRENT FORECAST TRACK HAS SHIFTED THE EXTENDED TRACK SOUTH OF THE PREVIOUS FORECASTS AT TAU 120 TO ALIGN WITH A SIMILAR SHIFT IN THE EXTENDED MODEL TRACK GUIDANCE. SPREAD IN THE GUIDANCE AT TAU 120 IS 353 NM, LENDING TO POOR CONFIDENCE IN THE EXTENDED TRACK FORECAST.// NNNN NNNN