MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI// SUBJ/PROGNOSTIC REASONING FOR TROPICAL STORM 01C (HALOLA) WARNING NR 12// RMKS/ 1. FOR METEOROLOGISTS. 2. 6 HOUR SUMMARY AND ANALYSIS. TROPICAL STORM (TS) 01C (HALOLA), LOCATED APPROXIMATELY 831 NM EAST-SOUTHEAST OF WAKE ISLAND, HAS TRACKED NORTHWESTWARD AT 11 KNOTS OVER THE PAST SIX HOURS. ANIMATED MULTISPECTRAL SATELLITE IMAGERY (MSI) SHOWS THE SYSTEM HAS MAINTAINED OVERALL CONVECTIVE SIGNATURE. THE INITIAL POSITION IS BASED ON THE MSI LOOP AND ON AGENCY FIXES. THE INITIAL INTENSITY OF 50 KNOTS IS BASED ON AN OVERALL ASSESSMENT OF DVORAK ESTIMATES FROM PGTW AND KNES AND IS SUPPORTED BY THE 2206Z ASCAT PASS. UPPER LEVEL ANALYSIS INDICATES THE SYSTEM IS IN AN AREA OF MODERATE (15-20 KNOT) NORTHERLY VWS. HOWEVER, THE VWS IS OFFSET BY STRONG RADIAL OUTFLOW THAT IS PROVIDING VENTILATION TO THE ASSOCIATED CONVECTION, AS EVIDENCED ON ANIMATED WATER VAPOR IMAGERY. THE CYCLONE IS TRACKING ALONG THE SOUTHERN PERIPHERY OF A DEEP-LAYERED STR TO THE NORTH. 3. FORECAST REASONING. A. THIS IS THE INITIAL JTWC PROGNOSTIC REASONING MESSAGE AND SETS THE FORECAST PHILOSOPHY.. B. TS 01C WILL CONTINUE TRACKING NORTHWESTWARD UNDER THE STEERING INFLUENCE OF THE STR. IT IS EXPECTED TO GRADUALLY INTENSIFY AS VIGOROUS OUTFLOW PERSISTS AND AS IT TRACKS ALONG WARM SSTS. ADDITIONALLY, VWS IS EXPECTED TO RELAX AS THE UPPER LEVEL WIND FLOW BECOMES MORE IN-PHASE WITH THE FORECAST STORM MOTION. THE SYSTEM WILL REACH TYPHOON STRENGTH BY TAU 24. C. IN THE EXTENDED PERIOD, TS HALOLA WILL CONTINUE TRACKING NORTHWESTWARD UNDER THE STEERING INFLUENCE OF THE STR. IT IS ALSO EXPECTED TO CONTINUE INTENSIFYING AS THE AFOREMENTIONED FAVORABLE CONDITIONS PERSIST. THE SYSTEM WILL REACH 95 KNOTS BY TAU 120. THE NUMERICAL MODEL GUIDANCE, ALBEIT LIMITED, IS IN GOOD AGREEMENT. THIS, IN ADDITION TO A STRAIGHTFORWARD STEERING MECHANISM, LENDS TO HIGH CONFIDENCE IN THE JTWC FORECAST TRACK.// NNNN NNNN