MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI// SUBJ/PROGNOSTIC REASONING FOR TROPICAL DEPRESSION 02W (SANBA) WARNING NR 21// RMKS// 1. FOR METEOROLOGISTS. 2. 6 HOUR SUMMARY AND ANALYSIS. TROPICAL DEPRESSION 02W (SANBA), LOCATED APPROXIMATELY 376 NM SOUTH OF MANILA, PHILIPPINES, HAS TRACKED WEST-SOUTHWESTWARD AT 16 KNOTS OVER THE PAST SIX HOURS. ANIMATED ENHANCED INFRARED SATELLITE IMAGERY DEPICTS A HIGHLY DISORGANIZED CONVECTIVE MASS NOW OVER OPEN WATER. THERE IS LOW CONFIDENCE IN THE INITIAL POSITION WHICH IS BASED ON SATELLITE FIXES AND A WEAK LOW REFLECTIVITY CIRCULATION FEATURE OBSERVED IN A 141850Z 85GHZ SSMI IMAGE. THE LOW LEVEL CIRCULATION CENTER APPEARS TO BE SUBSTANTIALLY DISRUPTED AFTER TRACKING OVER THE PHILIPPINE ARCHIPELAGO WITH NOTED MID-LEVEL TURNING DISPLACED SLIGHTLY WESTWARD OF THE BEST TRACK POSITION. THE INITIAL INTENSITY IS ASSESSED AT 25 KNOTS, HEDGED LOWER THAN AN RJTD DVORAK ESTIMATE OF T2.0 (30 KNOTS), AND BASED ON LOCAL SURFACE OBSERVATIONS WITH MULTIPLE STATIONS REPORTING MSLP OF 1009 MB. TD 02W IS POSITIONED JUST EQUATORWARD OF AN EAST-WEST ORIENTED DEEP-LAYERED SUBTROPICAL RIDGE STEERING THE SYSTEM WESTWARD. EASTERLY FLOW ALOFT IS CREATING A MARGINAL SHEAR ENVIRONMENT WITH SUBSTANTIAL DIFFLUENCE ON THE NORTHERN AND WESTERN SIDES. SSTS IN THE REGION ARE CURRENTLY SUPPORTIVE AROUND 27 CELSIUS. 3. FORECAST REASONING. A. THE FORECAST PHILOSOPHY HAS CHANGED WITH A TRACK DISPLACED FURTHER SOUTHWARD AND DISSIPATION OVER WATER BY TAU 96. B. TD 02W IS EXPECTED TO CONSOLIDATE QUICKLY OVER THE NEXT 6 TO 12 HOURS NOW THAT THE SYSTEM IS OVER OPEN WATER. PEAK INTENSITY IS FORECAST TO REACH 35 KNOTS BY TAU 24 WHILE IN AN AREA OF HIGH DIFFLUENCE AND WARM SSTS. THE STEERING RIDGE WILL CONTINUE TO STEER TD 02W ON A GENERALLY WESTWARD COURSE FOR THE DURATION OF THE FORECAST PERIOD. AFTER TAU 36 TD 02W WILL TRACK OVER INCREASINGLY COOLER SSTS. UNSUPPORTIVE SSTS, WORKING IN CONCERT WITH PERSISTENT WIND SHEAR WILL UNDOUBTEDLY WEAKEN THE SYSTEM BEYOND TAU 48. TD 02W IS FORECAST TO DISSIPATE BY TAU 96 AS A REMNANT TROPICAL LOW AND CONTINUE TO MOVE WESTWARD. DYNAMIC MODEL GUIDANCE SHOWS GENERAL AGREEMENT ON A WESTWARD TRACK FOR THE FORECAST PERIOD, BUT SLIGHT DIFFERENCES EXIST IN THE EXACT SYSTEM TRACK. UNCERTAINTY IN THE INITIAL POSITION IS AMPLIFIED IN FURTHER FORECAST POSITIONS. OVERALL THERE IS LOW CONFIDENCE IN THE FORECAST TRACK.// NNNN NNNN