MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI// SUBJ/PROGNOSTIC REASONING FOR TROPICAL DEPRESSION 27W (KALMAEGI) WARNING NR 007// RMKS/ 1. FOR METEOROLOGISTS. 2. 6 HOUR SUMMARY AND ANALYSIS. TROPICAL DEPRESSION (TD) 27W (KALMAEGI), LOCATED APPROXIMATELY 320 NM EAST OF MANILA, PHILIPPINES, HAS TRACKED NORTHWESTWARD AT 09 KNOTS OVER THE PAST SIX HOURS. ANIMATED MULTISPECTRAL SATELLITE IMAGERY (MSI) CONTINUES TO DEPICT A BROAD LOW-LEVEL CIRCULATION CENTER (LLCC) WITH MULTIPLE MESOVORTICES ROTATING CYCLONICALLY AROUND AN ILL-DEFINED CENTER. ANIMATED ENHANCED INFRARED SATELLITE IMAGERY SHOWS A LARGE AREA OF FLARING DEEP CONVECTION OVER THE NORTH AND NORTHWEST FLANK ASSOCIATED WITH STRONG LOW-LEVEL CONVERGENCE AND ROBUST POLEWARD OUTFLOW. A 140649Z SSMI 85GHZ COMPOSITE IMAGE INDICATES SHALLOW BANDING WRAPPING AROUND THE EASTERN AND NORTHERN SEMICIRCLES, HOWEVER; DEEP CONVECTION IS DISORGANIZED AND SHALLOW BANDING IS WEAK OVER THE SOUTHERN SEMICIRCLE. THUS, THE INITIAL POSITION IS BASED LARGELY ON A 140133Z ASCAT-B IMAGE, WHICH SHOWED AN ELONGATED, DEFINED CIRCULATION WITH 25-30 KNOT WINDS OVER THE EASTERN SEMICIRCLE. THE INITIAL INTENSITY REMAINS ASSESSED AT 30 KNOTS BASED ON THE ASCAT DATA AND A PGTW DVORAK ESTIMATE OF T2.0. ENVIRONMENTAL ANALYSIS REVEALS A FAVORABLE ENVIRONMENT WITH STRONG POLEWARD AND WESTWARD DIFFLUENCE ALOFT, WARM SST(29C) AND HIGH OCEAN HEAT CONTENT VALUES. TD 27W IS TRACKING ALONG THE SOUTHWESTERN PERIPHERY OF A SUBTROPICAL STEERING RIDGE SITUATED 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 CONTINUE TO TRACK NORTHWESTARD FOLLOWING THE SUBTROPICAL STEERING RIDGE FLOW FOR THE NEXT 48 HOURS, SLOWING AS THE STR WEAKENS TO THE NORTH IN RESPONSE TO A SHORTWAVE TROUGH PASSAGE. AFTER TAU 48, RIDGING IS EXPECTED TO BUILD TO THE NORTH OF THE SYSTEM, STEERING IT WEST-NORTHWESTWARD TOWARD LUZON. WITH THE EXCEPTION OF NAVGEM, WHICH TRACKS THE SYSTEM POLEWARD, NUMERICAL MODEL GUIDANCE INDICATES A TRACK OVER LUZON. BASED ON UNCERTAINTY IN THE CURRENT POSITION AND THE OBSERVED MODEL SPREAD, THERE IS LOW CONFIDENCE IN THIS PORTION OF THE FORECAST TRACK. C. AFTER TAU 72, TD 27W IS EXPECTED TO CONTINUE TRACKING WESTWARD ACROSS CENTRAL LUZON AND INTO THE SOUTH CHINA SEA UNDER THE INFLUENCE OF RIDGING TO THE NORTH. PASSAGE OVER LAND WILL RESULT IN STEADY WEAKENING. MODEL SPREAD PERSISTS INTO THE EXTENDED FORECAST PERIOD, LENDING LOW CONFIDENCE TO THE EXTENDED PORTION OF THE FORECAST TRACK.// NNNN NNNN