MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI// SUBJ/PROGNOSTIC REASONING FOR TROPICAL STORM 11W (KROSA) WARNING NR 022// RMKS/ 1. FOR METEOROLOGISTS. 2. 6 HOUR SUMMARY AND ANALYSIS. TROPICAL STORM (TS) 11W (KROSA), LOCATED APPROXIMATELY 795 NM SOUTHEAST OF IWAKUNI, JAPAN, HAS TRACKED NORTHWESTWARD AT 05 KNOTS OVER THE PAST SIX HOURS. ANIMATED MULTISPECTRAL SATELLITE IMAGERY DEPICTS DEEP CONVECTIVE BANDING WRAPPING AROUND A WELL-DEFINED LOW- LEVEL CIRCULATION CENTER (LLCC), WHICH SUPPORTS THE INITIAL POSITION WITH GOOD CONFIDENCE. A 102116Z SSMIS 91GHZ COLORPCT MICROWAVE IMAGE REVEALS NARROW DEEP CONVECTIVE BANDS WRAPPING TIGHTLY AROUND A 200NM DIAMETER CORE. A 110055Z ASCAT-B BULLSEYE IMAGE SHOWS WEAK CORE WINDS (10-35 KNOTS) WITH A SWATH OF 40-55 KNOT WINDS DISPLACED 90- 160NM FROM THE CENTER. DEEP CONVECTION OVER THE CORE AND NORTHWEST QUADRANT REMAIN WEAK DUE TO THE PRESENCE OF CYCLONIC FLOW AND CONVERGENCE ALOFT WHILE STRONG DIFFLUENCE OVER THE EASTERN AND SOUTHERN FLANK CONTINUE TO FUEL DEEP CONVECTIVE BANDING. THE INITIAL INTENSITY IS ASSESSED AT 60 KNOTS, HEDGED SLIGHTLY BELOW DVORAK CURRENT INTENSITY ESTIMATES OF 4.0 (65 KNOTS), BASED ON THE BROAD CONVECTIVE STRUCTURE. WITH THE EXCEPTION OF THE COMPLEX, MARGINALLY- FAVORABLE OUTFLOW, VERTICAL WIND SHEAR AND SST VALUES REMAIN FAVORABLE. TS 11W IS TRACKING SLOWLY NORTHWESTWARD ALONG THE SOUTHERN PERIPHERY OF A BUILDING SUBTROPICAL RIDGE (STR) POSITIONED TO THE NORTH. 3. FORECAST REASONING. A. THERE IS NO CHANGE TO THE FORECAST PHILOSOPHY SINCE THE PREVIOUS PROGNOSTIC REASONING MESSAGE. B. IN THE NEXT 72 HOURS, TS 11W WILL CONTINUE TRACKING NORTHWESTWARD ALONG THE SOUTHERN FLANK OF THE STR TO THE NORTH. SLIGHTLY DIMINISHED OUTFLOW, WEAK SUBSIDENCE AND POSSIBLE UPWELLING COOLER WATER WILL MAKE THE ENVIRONMENT SOMEWHAT UNFAVORABLE THROUGH TAU 12-36. AFTER TAU 36, ENVIRONMENTAL CONDITIONS ARE FORECAST TO IMPROVE WITH GRADUAL INTENSIFICATION. TS 11W SHOULD RE-INTENSIFY TO A PEAK INTENSITY OF 70 KNOTS BY TAU 72 AS POLEWARD OUTFLOW IMPROVES. C. AFTER TAU 72, TS 11W WILL RECURVE POLEWARD ALONG THE SOUTHWEST PERIPHERY OF THE STR, WHICH IS EXPECTED TO WEAKEN AND REORIENT WITH THE APPROACH OF A DEEP MIDLATITUDE SHORTWAVE TROUGH. SST VALUES WILL REMAIN CONDUCIVE (28-29C) THROUGH TAU 96. NUMERICAL MODEL GUIDANCE DIVERGES WITH A 160NM SPREAD IN SOLUTIONS AT TAU 96. BASED ON UNCERTAINTY IN THE LATER TAUS, THERE IS OVERALL MODERATE CONFIDENCE IN THE JTWC FORECAST TRACK.// NNNN NNNN