MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI// SUBJ/PROGNOSTIC REASONING FOR TROPICAL DEPRESSION 27W (KALMAEGI) WARNING NR 003// RMKS/ 1. FOR METEOROLOGISTS. 2. 6 HOUR SUMMARY AND ANALYSIS. TROPICAL DEPRESSION 27W (KALMAEGI), LOCATED APPROXIMATELY 447 NM EAST OF MANILA, PHILIPPINES, HAS TRACKED WEST-NORTHWESTWARD AT 08 KNOTS OVER THE PAST SIX HOURS. ANIMATED MULTISPECTRAL SATELLITE IMAGERY SHOWS A DISORGANIZED SYSTEM WITH DEEP AND FLARING CONVECTION SHEARED WESTWARD FROM A PARTIALLY EXPOSED LOW LEVEL CIRCULATION CENTER (LLCC). THE INITIAL POSITION IS PLACED WITH GOOD CONFIDENCE ON THE PARTIALLY EXPOSED LLCC. THE INITIAL INTENSITY OF 30 KNOTS IS BASED ON THE MULTI- AGENCY DVORAK ESTIMATES OF T1.5-2.0 (25-35 KNOTS). THE ENVIRONMENT IS OVERALL MARGINAL WITH WARM (29-30 DEGREES CELSIUS) SST AND STRONG WESTWARD OUTFLOW OFFSET BY A COLD NORTHERLY SURGE TO THE WEST OF TD 27W AND MODERATE (15-20 KNOTS) VERTICAL WIND SHEAR. THE CYCLONE IS TRACKING ALONG THE SOUTHWESTERN PERIPHERY OF THE SUBTROPICAL RIDGE (STR) TO THE NORTHEAST. 3. FORECAST REASONING. A. THERE IS NO SIGNIFICANT CHANGE TO THE FORECAST PHILOSOPHY FROM THE PREVIOUS PROGNOSTIC REASONING MESSAGE. B. TD 27W WILL TRACK NORTHWESTWARD ALONG THE SOUTHWEST EDGE OF THE STR AS IT GRADUALLY DEVELOPS DESPITE THE HIGH VWS ALONG ITS PROJECTED PATH. THE MARGINAL ENVIRONMENT WILL FUEL A MODEST INTENSIFICATION TO A PEAK OF 55 KNOTS BY TAU 72 AS IT DRIFTS EAST OF LUZON. THERE IS FAIR CONFIDENCE IN THIS PORTION OF THE FORECAST WITH A SPREAD OF 230NM BY TAU 72. C. AFTER TAU 72, TD 27W WILL CONTINUE TRACKING NORTHWESTWARD. A SLIGHT DROP IN INTENSITY IS EXPECTED AS TD 27W TRACKS ALONG THE NORTHEAST EDGE OF LUZON. THERE IS A WIDE SPREAD IN THE MODEL ENVELOPE WITH A BIFURCATION OCCURRING AT TAU 96. GFS AND ECMWF EXPECTS A SECOND STR TO THE WEST TO GAIN STEERING INFLUENCE WITH A SOUTHWESTERLY TRACK. WHEREAS GALWEM AND AFUM TRACK TD 27W ALONG A RECURVE SCENARIO AROUND ITS INITIAL STR CURRENTLY POSITIONED TO THE NORTHEAST. THE UNCERTAINTY IN THE STORM MOTION LEND LOW CONFIDENCE IN THE JTWC FORECAST TRACK.// NNNN NNNN