MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI// SUBJ/PROGNOSTIC REASONING FOR TROPICAL STORM 09W (CHAN-HOM) WARNING NR 03// RMKS/ 1. FOR METEOROLOGISTS. 2. 6 HOUR SUMMARY AND ANALYSIS. TROPICAL STORM 09W (CHAN-HOM), LOCATED APPROXIMATELY 217 NM NORTH-NORTHEAST OF OROLUK, HAS TRACKED WEST-NORTHWESTWARD AT 19 KNOTS OVER THE PAST SIX HOURS. ANIMATED MSI SHOWS A HIGHLY SYMMETRICAL CLOUD FEATURE WITH A SLIGHT DIMPLE IN THE CENTER AND GOOD BANDING. THE HIGH RESOLUTION HIMAWARI LOOP CLEARLY SHOWS OVERSHOOTING TOPS AND BUBBLING CONVECTION INDICATIVE OF THE SYSTEM BEING VERTICALLY STACKED. IN THE WAKE OF THE SYSTEM, AN INDUCED CIRCULATION SEEMS TO HAVE BEEN MADE, WHICH CAN BE SEEN IN THE MSI AS WELL AS THE HIMAWARI LOOP AND AN EARLIER (301937Z) WINDSAT PASS. HOWEVER, THE ACTUAL LLCC IS CURRENTLY ASSESSED AS UNDER THE DEEP CONVECTION WITH FAIR CONFIDENCE. DUE TO THE UPDATED LOCATION OF THE SYSTEM, THE ACTUAL SPEED OF THE SYSTEM IS CLOSER TO 15 KNOTS, VICE THE MOVEMENT ASSESSED AT 19 KNOTS BASED ON THE 18Z WARNING. UPPER LEVEL ANALYSIS INDICATES THAT THE SYSTEM HAS A POINT SOURCE ABOVE IT, OFFSETTING THE 20 KNOTS OF VWS. TS 09W IS CURRENTLY TRACKING NORTHWESTWARD ALONG THE SOUTHERN PERIPHERY OF A STR. 3. FORECAST REASONING. A. THERE IS NO CHANGE TO THE FORECAST PHILOSOPHY. B. TS 09W WILL GENERALLY MAINTAIN A WESTWARD TRAJECTORY THROUGH TAU 48 WITH THE STR BEING THE MAIN STEERING INFLUENCE. THROUGHOUT THIS TIME EXPECT AN INCREASE IN INTENSITY AS ENVIRONMENTAL CHARACTERISTICS REMAIN FAVORABLE. BEYOND TAU 48, THE STEERING ENVIRONMENT BECOMES MORE COMPLICATED AS TS CHAN-HOM BEGINS TO INTERACT WITH A TROPICAL AREA OF DISTURBANCE MENTIONED IN THE ABPW10 PGTW 301500. ADDITIONALLY, THE STR WILL BEGIN TO RETREAT TO THE EAST, ALLOWING TS 09W TO ADD A NORTHWARD COMPONENT TO ITS TRACK. C. IN THE EXTENDING FORECAST PERIOD, EXPECT TS 09W TO ABSORB THE ENERGY ASSOCIATED WITH THE SYSTEM MENTIONED ABOVE (94W) AND TRACK MORE TO THE NORTHWEST. MODEL GUIDANCE STRUGGLES WITH THE OVERALL STEERING ENVIRONMENT BETWEEN TAU 48 AND 120, BUT OVERALL IS IN DECENT AGREEMENT AS TO THE EXTENT OF THE NORTHWARD TURN IN THE WAKE OF THE STEERING STR. DUE TO THE DIFFERENCES IN MODEL GUIDANCE AND THE CHANGES IN INITIAL SPEED AND POSITION OF THE SYSTEM, THERE IS LOW CONFIDENCE IN THE JTWC TRACK FORECAST, WHICH IS PLACED CLOSE TO THE MULTI MODEL CONSENSUS.// NNNN NNNN