WDPN31 PGTW 280900
MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI//
SUBJ/PROGNOSTIC REASONING FOR TROPICAL DEPRESSION 22W (TWENTY-TWO) WARNING NR 002//
RMKS/
1. FOR METEOROLOGISTS.
2. 6 HOUR SUMMARY AND ANALYSIS.
   TROPICAL DEPRESSION 22W (TWENTYTWO), LOCATED APPROXIMATELY 1110 NM EAST OF MANILA, PHILIPPINES, HAS TRACKED WESTWARD AT 06 KNOTS OVER THE PAST SIX HOURS. ANIMATED MULTISPECTRAL SATELLITE IMAGERY (MSI) DEPICTS A SMALL SYSTEM WITH FLARING, ALBEIT CONSOLIDATING, CENTRAL CONVECTION WITH VERY MINIMAL RAIN BANDS. THE INITIAL POSITION IS PLACED WITH FAIR CONFIDENCE BASED ON LOW CLOUD TRACING INTO AN OBSCURED LOW LEVEL CIRCULATION (LLC) IN THE MSI LOOP THAT LINED UP WELL WITH A FAINT, PARTLY OBSCURED, BUT DISCERNIBLE LLC FEATURE IN THE 280429Z ATMS MICROWAVE IMAGE. THE INITIAL INTENSITY OF 30KTS IS BASED ON MULTI AGENCY DVORAK ESTIMATES OF T1.5/25KTS TO T2.0/30KTS TO REFLECT THE SLIGHT 6-HR IMPROVEMENT. TD 22W IS TRACKING ALONG THE SOUTHERN PERIPHERY OF A DEEP-LAYERED SUBTROPICAL RIDGE (STR) TO THE NORTH OVER WARM (29-30C) SEA SURFACE TEMPERATURES (SST) IN THE PHILIPPINE SEA AND UNDER LOW (5-10KT) VERTICAL WIND SHEAR (VWS) AND GOOD RADIAL OUTFLOW.
3. FORECAST REASONING.
   A. THERE IS NO SIGNIFICANT CHANGE TO THE FORECAST PHILOSOPHY FROM THE LAST PROGNOSTIC REASONING MESSAGE.
   B. TD 22W WILL TRACK WESTWARD THROUGH TAU 12, THEN WEST-SOUTHWESTWARD AS THE STR BUILDS, AND BY TAU 72, WILL BE APPROXIMATELY 375NM EAST-SOUTHEAST OF MANILA. THE AFOREMENTIONED FAVORABLE CONDITIONS WILL PROMOTE GRADUAL INTENSIFICATION UP TO TAU 48, THEN RAPID INTENSIFICATION TO A PEAK OF 105KTS BY TAU 72 AS IT DRIFTS OVER A WARMER (31C+ SST) POOL OF WATER IN THE PHILIPPINE SEA.
   C. AFTER TAU 72, THE SYSTEM WILL RETURN TO A WESTWARD THEN WEST-NORTHWESTWARD TRACK AS THE STR WEAKENS SLIGHTLY WITH THE APPROACH OF A MINOR SHORTWAVE TROUGH FROM THE NORTHWEST, MAKING LANDFALL OVER SOUTHERN LUZON, PHILIPPINES AROUND TAU 96, TRACK NEAR MANILA, THEN EXIT INTO THE SOUTH CHINA BY TAU 108. INTERACTION WITH THE RUGGED TERRAIN IN ADDITION TO INCREASED VWS (20KTS), WILL LEAD TO A WEAKENING IN INTENSITY TO 65 KTS BY TAU 120.  NUMERICAL MODELS ARE IN TIGHT AGREEMENT WITH NAVGEM THE SOLE RIGHT-OF-TRACK OUTLIER, LENDING AN OVERALL GOOD CONFIDENCE IN ALL PORTIONS OF THE JTWC FORECAST TRACK WHICH IS LAID SLIGHTLY LEFT OF THE MULTI-MODEL CONSENSUS.//
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