MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI// SUBJ/PROGNOSTIC REASONING FOR TROPICAL STORM 30W (PHANFONE) WARNING NR 003// RMKS/ 1. FOR METEOROLOGISTS. 2. 6 HOUR SUMMARY AND ANALYSIS. TROPICAL STORM (TS) 30W (PHANFONE), LOCATED APPROXIMATELY 96 NM SOUTH OF YAP, HAS TRACKED NORTHWESTWARD AT 14 KNOTS (KTS) OVER THE PAST SIX HOURS. THERE IS FAIR CONFIDENCE IN THE INITIAL POSITION BASED OFF ANIMATED MULTISPECTRAL SATELLITE IMAGERY (MSI) WHICH SHOWS SUSTAINED DEEP CONVECTION TO THE NORTHWEST OF A PARTIALLY EXPOSED LOW LEVEL CIRCULATION (LLC). THE 35 KT INITIAL INTENSITY IS BASED ON AN AVERAGE OF PGTW/RJTD DVORAK ESTIMATES OF T2.0-T2.5 (30-35 KTS) AND A 220406Z CIMSS SATCON ESTIMATE OF 40 KTS. THE ENVIRONMENT IS VERY FAVORABLE WITH LOW (10-15 KT) VERTICAL WIND SHEAR, GOOD POLEWARD AND EQUATORWARD OUTFLOW CHANNELS, AND WARM (29-30 CELSIUS) SEA SURFACE TEMPERATURE. TS 30W IS TRACKING ALONG THE SOUTHERN PERIPHERY OF A SUBTROPICAL RIDGE (STR). 3. FORECAST REASONING. A. NO CHANGE TO THE FORECAST PHILOSOPHY SINCE THE PREVIOUS PROGNOSTIC REASONING MESSAGE. B. TS 30W WILL FOLLOW A WEST-NORTHWESTWARD TO NORTHWESTWARD TRACK FOR THE DURATION OF THE FORECAST. THE FAVORABLE ENVIRONMENT WILL SUPPORT STEADY, POSSIBLY RAPID, INTENSIFICATION PRIOR TO LANDFALL IN THE CENTRAL PHILIPPINES SHORTLY AFTER TAU 48. LAND INTERACTION WILL INHIBIT FURTHER INTENSIFICATION THROUGH TAU 72. WITH THE EXCEPTION OF NAVGEM, WHICH IS A SLIGHT NORTHERN OUTLIER, NUMERICAL MODEL GUIDANCE IS IN GOOD AGREEMENT, LENDING TO GOOD CONFIDENCE THROUGH TAU 72. C. AFTER TAU 72, TS 30W WILL EMERGE OVER THE SOUTH CHINA SEA AND CONTINUE TO TRACK WEST-NORTHWESTWARD. ONCE OVER WATER, SLIGHT INTENSIFICATION IS EXPECTED UNTIL HIGH VWS AND INTERACTION WITH RELATIVELY COOL, DRY AIR CAUSES WEAKENING BY TAU 120. WITH THE EXCEPTION OF NAVGEM, NUMERICAL MODEL GUIDANCE REMAINS IN FAIR AGREEMENT IN THE EXTENDED PERIOD. THE JTWC TRACK FORECAST IS HEDGED JUST SOUTH OF CONSENSUS TO OFFSET THE INFLUENCE OF NAVGEM, WITH FAIR CONFIDENCE.// NNNN NNNN