MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI// SUBJ/PROGNOSTIC REASONING FOR TROPICAL DEPRESSION 09W (CHAN-HOM) WARNING NR 01// RMKS// 1. FOR METEOROLOGISTS. 2. 6 HOUR SUMMARY AND ANALYSIS. TROPICAL DEPRESSION (TD) 09W (CHAN-HOM), LOCATED APPROXIMATELY 204 NM NORTHEAST OF POHNPEI, HAS TRACKED WESTWARD AT 03 KNOTS OVER THE PAST SIX HOURS. ANIMATED EIR DEPICTS DEEPENED CENTRAL CONVECTION WITH FORMATIVE BANDS WRAPPING INTO AN OBSCURED LLCC. A 301021Z ASCAT PASS SHOWS 15 TO 20 KNOT CORE WINDS WITH STRONGER (25 TO 30 KNOT) WINDS SURROUNDING CIRCULATION. THE CURRENT POSITION IS BASED ON THE EIR LOOP AND THE AFOREMENTIONED ASCAT PASS WITH GOOD CONFIDENCE. THE INITIAL INTENSITY OF 30 KNOTS IS BASED ON MATCHING DVORAK INTENSITY ESTIMATES OF T2.0 FROM BOTH PGTW AND RJTD. UPPER-LEVEL ANALYSIS INDICATES 09W IS LOCATED IN A MODERATE (20 KNOT) VWS BEING OFFSET BY THE EXCELLENT OUTFLOW, NAMELY THE POLEWARD CHANNEL ENHANCED BY THE TUTT CELL LOCATED TO THE NORTH. TD 09W IS CURRENTLY TRACKING GENERALLY WESTWARD ALONG THE SOUTHERN PERIPHERY OF A STR TO THE NORTH. 3. FORECAST REASONING. A. THIS IS THE INITIAL PROGNOSTIC REASONING AND SETS THE FORECAST PHILOSOPHY. B. TD 09W WILL MAINTAIN A WESTWARD TRAJECTORY THROUGH TAU 72. MODERATE VWS WILL PERSIST, BUT FAVORABLE SST AND HIGH OHC CONTENT VALUES WILL ALLOW THE SYSTEM TO GRADUALLY INTENSIFY. AVAILABLE MODEL GUIDANCE IS OVERALL IN GOOD AGREEMENT, LENDING HIGH CONFIDENCE DURING THIS PERIOD. FURTHERMORE, AS TD 09W CONTINUES TO TRACK WESTWARD, THERE IS A POSSIBILITY THAT THE SYSTEM WILL CONSUME AND/OR SUFFOCATE 94W, THE DISTURBANCE THAT IS LOCATED NEAR 8.5N 148.8E (SEE ABPW BULLETIN FOR FURTHER DETAILS ON THIS DISTURBANCE). C. AFTER TAU 72, AN APPROACHING UPPER-LEVEL TROUGH PASSING TO THE NORTH WILL WEAKEN THE STR, CAUSING TD 09W TO SHIFT NORTHWESTWARD. DUE TO DIFFERENCES IN TRACK SPEEDS AMONG AVAILABLE TRACKERS, THERE IS LOW CONFIDENCE IN THE JTWC TRACK FORECAST FOR THIS PERIOD.// NNNN NNNN