WDPN31 PGTW 140300
MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI//
SUBJ/PROGNOSTIC REASONING FOR TROPICAL DEPRESSION 01W (ONE) WARNING 
NR 03//
RMKS//
1. FOR METEOROLOGISTS.
2. 6 HOUR SUMMARY AND ANALYSIS.
   TROPICAL DEPRESSION (TD) 01W (ONE), LOCATED APPROXIMATELY 112 NM 
EAST-NORTHEAST OF YAP, HAS TRACKED NORTHWESTWARD AT 11 KNOTS OVER 
THE PAST SIX HOURS. ANIMATED MULTISPECTRAL SATELLITE IMAGERY DEPICTS 
DEEPENED CONVECTION DISPLACED TO THE NORTHWEST OF A PARTIALLY-
EXPOSED LOW-LEVEL CIRCULATION CENTER (LLCC). A 140011Z METOP-B 
MICROWAVE IMAGE REVEALS THE BULK OF DEEP CONVECTIVE BANDING OVER THE 
NORTHERN SEMI-CIRCLE WRAPPING INTO THE CENTER. THE CURRENT POSITION 
IS BASED ON THE MSI AND SATELLITE FIXES FROM PGTW AND RJTD WITH GOOD 
CONFIDENCE. THE INITIAL INTENSITY OF 30 KNOTS IS BASED ON IMPROVED 
ORGANIZATION AND AN OVERALL ASSESSMENT OF DVORAK INTENSITY ESTIMATES 
FROM ALL REPORTING AGENCIES. UPPER-LEVEL ANALYSIS INDICATES TD 01W 
IS LOCATED IN AN AREA OF MODERATE (10 TO 20 KNOTS) VERTICAL WIND 
SHEAR (VWS) OFFSET BY EXCELLENT POLEWARD OUTFLOW. TD 01W IS 
CURRENTLY TRACKING ALONG THE SOUTHWESTERN PERIPHERY OF A SUBTROPICAL 
RIDGE (STR) TO THE NORTHEAST.
3. FORECAST REASONING.
   A. NO CHANGE TO THE FORECAST PHILOSOPHY SINCE THE PREVIOUS 
PROGNOSTIC REASONING MESSAGE.
   B. TD 01W WILL CONTINUE TO TRACK NORTHWESTWARD UNDER THE STEERING 
INFLUENCE OF THE WEAKENED STR AS A MIGRATORY TROUGH PASSES OVER 
SOUTHERN JAPAN. AFTER TAU 48, THE STR IS EXPECTED TO REBUILD AND 
EXTEND WESTWARD CONTINUING TO DOMINATE THE STEERING ENVIRONMENT. THE 
NORTHEASTERLY SURGE EVENT WILL KEEP THE SYSTEM TO THE SOUTH AND 
POSSIBLY LIMIT OVERALL INTENSIFICATION. AVAILABLE MODEL GUIDANCE IS 
IN GOOD AGREEMENT THROUGH TAU 48, LENDING TO HIGH CONFIDENCE FOR 
THIS FORECAST PERIOD.
   C. AFTER TAU 72, TD 01W IS EXPECTED TO REMAIN ON A NORTHWESTWARD 
TRAJECTORY. BY TAU 96, LAND INTERACTION WITH CENTRAL PHILIPPINES 
WILL WEAKEN THE SYSTEM. DUE TO THE DIVERGENCE AMONG MODEL TRACKERS 
AT TAU 72, THE CONFIDENCE LEVEL FOR THIS EXTENDED PORTION OF THE 
FORECAST REMAINS LOW.//
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