WDPN31 PGTW 310300 MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI// SUBJ/PROGNOSTIC REASONING FOR TROPICAL STORM 13W (SOUDELOR) WARNING NR 04// RMKS/ 1. FOR METEOROLOGISTS. 2. 6 HOUR SUMMARY AND ANALYSIS. TROPICAL STORM (TS) 13W (SOUDELOR), LOCATED APPROXIMATELY 261 NM WEST-NORTHWEST OF ENEWETAK, HAS TRACKED SOUTHWESTWARD AT 03 KNOTS OVER THE PAST SIX HOURS. ANIMATED MSI SHOWS A DEEP SMALL, CDO FEATURE OBSCURING THE LLCC WITH GOOD, ALBEIT, SLIGHTLY FRACTURED BANDING WRAPPING INTO THE CENTER. THE INITIAL POSITION IS BASED ON THE ABOVE IMAGERY AND A 302050Z SSMIS 91H IMAGE WITH LOW CONFIDENCE. THE MICROWAVE IMAGE REINFORCES THE SUBSIDENCE SEEN IN THE MSI ON THE NORTHWESTERN SIDE OF THE LLCC, REDUCING THE CONVECTION IN THE ENTIRE EASTERN SECTOR OF THE SYSTEM. THE INITIAL INTENSITY IS MAINTAINED AT 40 KNOTS BASED ON DVORAK ESTIMATES FROM PGTW, KNES, AND RJTD. UPPER- LEVEL ANALYSIS INDICATES A FAVORABLE ENVIRONMENT WITH MODERATE VWS OFFSET BY NEAR RADIAL OUTFLOW IN ADDITION TO A POLEWARD TAP CAUSED BY A TUTT CELL TO THE NORTH. THE CYCLONE IS CURRENTLY TRACKING ALONG THE SOUTHERN PERIPHERY OF A DEEP-LAYERED STR. 3. FORECAST REASONING. A. THERE IS NO SIGNIFICANT CHANGE TO THE FORECAST PHILOSOPHY FROM THE PREVIOUS PROGNOSTIC REASONING MESSAGE. B. TS 13W IS FORECAST TO TRACK GENERALLY TO THE WEST-NORTHWEST THROUGHOUT THE FORECAST UNDER THE STEERING INFLUENCE OF THE STR. WHILE THE AFOREMENTIONED SUBSIDENCE ON THE NORTHWESTERN SIDE OF THE SYSTEM MAY INHIBIT RAPID INTENSIFICATION IN THE SHORT TERM, EXPECT A GRADUAL INCREASE IN INTENSITY THROUGH TAU 72 DUE TO GOOD POLEWARD OUTFLOW, DECREASING VWS, AND HIGH OHC THROUGH THE NORTHERN MARIANAS ISLAND CHAIN. C. IN THE EXTENDED FORECAST, THE PERSISTENT CONDUCIVE UPPER-LEVEL ENVIRONMENT WILL CONTINUE ALLOWING A PEAK INTENSITY OF 125 KNOTS BY TAU 96. EXPECT A SLIGHTLY MORE POLEWARD TRACK AS THE DEEP STR OVER JAPAN TRACKS TO THE EAST BY THIS TIME. TS SOUDELOR'S GROWTH WILL BE TEMPERED BY A DECREASE IN OHC AS THE SYSTEM TRACKS NORTH OF THE 20TH PARALLEL, CAUSING A SLIGHT DECAY IN TS 13W�??S INTENSITY. DYNAMIC MODEL GUIDANCE CONTINUES TO BE IN GOOD AGREEMENT, WITH AN AVERAGE SPREAD OF MODEL TRACKS BEYOND TAU 72. HOWEVER, DUE TO THE LOW CONFIDENCE IN THE INITIAL POSITION AND ITS AFFECT ON THE PERSISTENCE OF THE TRACK, THERE IS OVERALL LOW CONFIDENCE IN THE JTWC FORECAST TRACK, WHICH IS LAID CLOSE TO THE MULTI-MODEL CONSENSUS.// NNNN