WDPN32 PGTW 030900 MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI// SUBJ/PROGNOSTIC REASONING FOR TROPICAL STORM 10W (LINFA) WARNING NR 06// RMKS// 1. FOR METEOROLOGISTS. 2. 6 HOUR SUMMARY AND ANALYSIS. TROPICAL STORM (TS) 10W (LINFA), LOCATED APPROXIMATELY 292 NM EAST OF MANILA, PHILIPPINES, HAS TRACKED SOUTHWESTWARD AT 07 KNOTS OVER THE PAST SIX HOURS. ANIMATED MULTISPECTRAL SATELLITE IMAGERY (MSI) DEPICTS A COMPACT CENTRAL DENSE OVERCAST OVER A LOW LEVEL CIRCULATION CENTER (LLCC). A 030524Z NPP 165 GHZ PASS REVEALS A HOOK IN THE DEEP CONVECTION. THE CURRENT POSITION IS BASED ON THE PGTW FIX AND NOTED MICROWAVE IMAGE WITH GOOD CONFIDENCE. THE CURRENT INTENSITY IS ASSESSED AT 45 KNOTS BASED ON AN ASSESSMENT OF DVORAK CURRENT INTENSITY ESTIMATES. TS LINFA IS TRACKING ALONG THE SOUTHWESTERN PERIPHERY OF AN EXTENSION OF A SUBTROPICAL RIDGE (STR) TO THE EAST. UPPER LEVEL ANALYSIS INDICATES THE SYSTEM IS IN A FAIR ENVIRONMENT WITH HIGH (20-25 KNOT) NORTHEASTERLY VERTICAL WIND SHEAR (VWS) BEING OFFSET BY EXCELLENT EQUATORWARD OUTFLOW. 3. FORECAST REASONING. A. THERE IS NO SIGNIFICANT CHANGE TO THE FORECAST PHILOSOPHY FROM THE PREVIOUS PROGNOSTIC REASONING BULLETIN. B. TS 10W WILL REMAIN ON A WEST-NORTHWESTWARD TRAJECTORY THROUGH TAU 72. THE TRACK WAS SHIFTED SOUTH SLIGHTLY AS A RESULT OF THE RECENT SOUTHWESTERLY MOTION, AND NOW LIES OVER THE NORTHERN TIP OF LUZON. TS LINFA WILL SLOWLY INTENSIFY THROUGH TAU 36, HAMPERED BY PERSISTENT VWS. THE SYSTEM WILL WEAKEN SLIGHLY OVERLAND BEFORE EMERGING IN THE LUZON STRAIGHT, WHERE RE-INSTENSIFICATION WILL BEGIN. NUMERICAL GUIDANCE IS IN RELATIVELY GOOD AGREEMENT THROUGH TAU 72, GIVING HIGH CONFIDENCE IN THIS PORTION OF THE FORECAST. C. BEYOND TAU 72, NUMERICAL GUIDANCE IS CALLING FOR A SHORT-WAVE TROUGH TO MOVE OVER TS 10W AND BREAK IN THE WESTERN PERIPHERY OF THE STEERING RIDGE, CAUSING THE SYSTEM TO RECURVE TO THE EAST. THE TROUGH WILL ALSO DEGRADE THE UPPER LEVEL CONDITIONS, LEADING TO WEAKENING. IN ADDITION, THE APPROACH OF TS 09W FROM THE EAST MAY INITIATE A DIRECT CYCLONE INTERACTION (DCI), CAUSING THE TRACK AND INTENSITY OF TS LINFA TO BECOME MORE COMPLEX. MODEL SOLUTIONS DIVERGE SIGNIFICANTLY AFTER TAU 72 WITH THE MAJORITY OF GUIDANCE RECURVING THE SYSTEM NORTH. THIS DIVERGENCE, IN ADDITION TO THE UNCERTAINTY OF POTENTIAL DCI WITH TS 09W, LENDS LOW CONFIDENCE IN THE JTWC TRACK FORECAST.// NNNN