WDPN31 PGTW 021500 MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI// SUBJ/PROGNOSTIC REASONING FOR TROPICAL STORM 03W (FAXAI) WARNING NR 11// RMKS// 1. FOR METEOROLOGISTS. 2. 6 HOUR SUMMARY AND ANALYSIS. TROPICAL STORM (TS) 03W (FAXAI), LOCATED APPROXIMATELY 338 NM SOUTHEAST OF ANDERSEN AFB, GUAM, HAS TRACKED NORTH-NORTHEASTWARD AT 04 KNOTS OVER THE PAST SIX HOURS. ANIMATED ENHANCED INFRARED (EIR) SATELLITE IMAGERY DEPICTS THE DEEP CONVECTION SHEARED OFF TO THE WEST OVER A PARTIALLY-EXPOSED LOW-LEVEL CIRCULATION CENTER (LLCC). A 021141Z NOAA-19 MICROWAVE IMAGE REVEALS CONVECTIVE BANDING WRAPPING INTO THE WELL-DEFINED LLCC. A 021056Z PARTIAL ASCAT PASS SHOWS 40 TO 45 KNOT WINDS ALONG THE WESTERN PERIPHERY. THE CURRENT POSITION IS BASED ON THE EIR ANIMATION AND AFOREMENTIONED MICROWAVE IMAGE WITH HIGH CONFIDENCE. THE INITIAL INTENSITY IS ASSESSED AT 45 KNOTS, BASED ON THE PARTIAL ASCAT PASS AND DVORAK CURRENT INTENSITY ESTIMATES FROM PGTW AND KNES. TS 03W APPEARS TO BE TRACKING SLOWLY NORTHWARD UNDER THE STEERING INFLUENCE OF A WEAKENING EXTENSION OF THE SUBTROPICAL RIDGE (STR) POSITIONED TO THE NORTH. 3. FORECAST REASONING. A. NO CHANGE IN THE FORECAST PHILOSOPHY FROM THE PREVIOUS PROGNOSTIC REASONING MESSAGE. B. TS 03W IS EXPECTED TO TURN NORTHWARD AS THE STR EXTENSION CONTINUES TO WEAKEN DUE TO IMPINGING WESTERLY FLOW AND THE STR RE- ORIENTS POLEWARD. AS THE STR BUILDS TO THE EAST, TS 03W IS FORECAST TO ACCELERATE AND TURN NORTHEASTWARD AS IT ROUNDS THE NORTHWESTERN PERIPHERY OF THE STR. THE SYSTEM IS EXPECTED TO INTENSIFY THROUGH TAU 36 TO A PEAK INTENSITY OF 60 KNOTS DUE TO WEAK VWS AND ROBUST POLEWARD OUTFLOW. AFTER TAU 48, VERTICAL WIND SHEAR ASSOCIATED WITH THE WESTERLIES SHOULD INCREASE LEADING TO A GRADUAL WEAKENING TREND. C. IN THE EXTENDED PERIOD, TS FAXAI WILL BEGIN TO ACCELERATE NORTHEASTWARD AS IT BEGINS TO ENCOUNTER WESTERLY FLOW, POLEWARD OF THE STR AXIS. TS 03W SHOULD BEGIN EXTRA-TROPICAL TRANSITION (ETT) NEAR TAU 72 AND SHOULD COMPLETE ETT BY TAU 96 AS IT BECOMES EMBEDDED WITHIN THE MIDLATITUDE WESTERLIES. DUE TO THE UNCERTAINTY IN THE SHORT-TERM MOTION, THERE IS OVERALL LOW CONFIDENCE IN THE JTWC FORECAST TRACK.// 4. JUSTIFICATION FOR RELOCATION: THE POSITION IN THE PREVIOUS FORECAST WAS BASED ON THE MULTISPECTRAL SATELLITE IMAGERY SHOWING A CENTRAL DENSE OVERCAST (CDO) FEATURE OBSCURING THE LOW-LEVEL CIRCULATION CENTER. THEREFORE, THE LLCC WAS ASSESSED FARTHER WEST FROM THE CURRENT POSITION. NNNN