MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI// SUBJ/PROGNOSTIC REASONING FOR TROPICAL DEPRESSION 03W (THREE) WARNING NR 001// RMKS// 1. FOR METEOROLOGISTS. 2. 6 HOUR SUMMARY AND ANALYSIS. TROPICAL DEPRESSION 03W (THREE), LOCATED APPROXIMATELY 324 NM SOUTH OF NAVSTA GUAM, HAS TRACKED WESTWARD AT 10 KNOTS OVER THE PAST SIX HOURS. ANIMATED MULTISPECTRAL SATELLITE IMAGERY (MSI) DEPICTS A PARTIALLY EXPOSED LOW LEVEL CIRCULATION CENTER (LLCC) WITH DEEP CONVECTION PRIMARILY DISPLACED TO THE NORTH AND IN A DEEP CONVECTIVE BAND TO THE EAST. ALTHOUGH AN OLDER 141206Z ASCAT PASS SHOWED A WAVELIKE PATTERN WITH CYCLONIC TURNING AND STRONGER 25-30 KT WINDS ONLY TO THE NORTH AND NO RETURN FLOW, A 142049Z SSMIS 91GHZ MICROWAVE IMAGE DEPICTS SHALLOW BANDING WRAPPING INTO THE LLCC FROM THE SOUTHWEST. THE INITIAL POSITION IS BASED ON THE PARTIALLY EXPOSED LLCC WITH HIGH CONFIDENCE. THE INITIAL INTENSITY IS ASSESSED AT 25 KNOTS BASED ON THE APPARENT CLOSED CIRCULATION IN MSI AND MICROWAVE IMAGERY, THE AFOREMENTIONED ASCAT PASS, AND MULTIAGENCY DVORAK CURRENT INTENSITY ESTIMATES OF T1.0 (25 KTS). ENVIRONMENTAL CONDITIONS ARE MARGINALLY FAVORABLE WITH MODERATE (15- 20 KT) SOUTHWESTERLY VERTICAL WIND SHEAR, GOOD POLEWARD OUTFLOW, AND ADEQUATE SEA SURFACE TEMPERATURES (26 TO 28C). TD 02W IS CURRENTLY TRACKING WESTWARD ALONG THE SOUTHEASTERN PERIPHERY OF A DEEP LAYER SUBTROPICAL RIDGE (STR) POSITIONED TO THE NORTH AND NORTHWEST. 3. FORECAST REASONING. A. THIS IS THE FIRST PROGNOSTIC REASONING MESSAGE AND SETS THE FORECAST PHILOSOPHY. B. THROUGH TAU 72, TD 02W IS EXPECTED TO TRACK WESTWARD TO WEST- SOUTHWESTWARD ALONG THE SOUTHERN PERIPHERY OF A DEEP-LAYERED STR TO THE NORTH. A TROUGH APPROACHING FROM THE NORTHWEST IS WEAKENING THE STR, ALLOWING FOR GOOD POLEWARD OUTFLOW. DUE TO THE MARGINAL VWS AND SSTS, AND GOOD POLEWARD OUTFLOW, TD 03W IS FORECAST TO SLOWLY INTENSIFY TO 30 KTS BY TAU 30. AFTER TAU 30, THE STR WILL BUILD BACK IN TO THE NORTH OF TD 03W, LEADING TO DIMINISHING POLEWARD OUTFLOW AND A MOSTLY WESTWARD TRACK. THOUGH MODELS ARE IN GOOD NORTH-SOUTH AGREEMENT, ECMWF PREDICTS A FASTER ALONG-TRACK MOTION THAN DO THE OTHER MODELS. C. AFTER TAU 72, SURFACE RIDGING BUILDING IN NEAR JAPAN WILL RESULT IN COLD, DRY NORTHEASTERLY SURGE NEGATIVELY IMPACTING TD 03W. IN ADDITION TO THE DRY AIR AND HIGHER VWS, LAND INTERACTION AS TD 03W CROSSES MINDANAO WILL LEAD TO FURTHER WEAKENING AND DISSIPATION BY TAU 96. GIVEN THE POOR ORGANIZATION OF THE CIRCULATION, EARLIER DISSIPATION INTO A TROPICAL WAVE VICE A TROPICAL CYCLONE IS POSSIBLE. DUE TO THE DIFFERENCES IN ALONG-TRACK SPEED, THERE IS FAIR CONFIDENCE IN THE JTWC TRACK FORECAST.// NNNN NNNN