WDPN31 PGTW 091500
MSGID/GENADMIN/NAVMARFCSTCEN PEARL HARBOR HI/JTWC//
SUBJ/PROGNOSTIC REASONING FOR TROPICAL DEPRESSION 05W WARNING NR 03//
RMKS/
1. FOR METEOROLOGISTS.
2. 12 HOUR SUMMARY AND ANALYSIS.
   A. TROPICAL DEPRESSION (TD) 05W, LOCATED APPROXIMATELY 190 NM 
NORTHWEST OF MANILA, PHILIPPINES, HAS TRACKED NORTH-
NORTHWESTWARD AT 12 KNOTS OVER THE PAST SIX HOURS. ANIMATED INFRARED 
SATELLITE IMAGERY SHOWS CURVED INFLOW INTO A LOW LEVEL CIRCULATION 
CENTER. A 091231Z SSMIS MICROWAVE IMAGE SHOWS A DECREASE IN 
CONVECTIVE BANDING WITH MOST OF THE DEEP CONVECTION ALONG THE 
SOUTHERN PERIPHERY. WATER VAPOR IMAGERY INDICATES A TROPICAL UPPER 
LEVEL TROPOSPHERIC TROUGH (TUTT) LOCATED TO THE NORTH IS CURRENTLY 
INHIBITING CONVECTION AND OUTFLOW ALONG THE NORTHERN PERIPHERY. 
EQUATORWARD OUTFLOW REMAINS FAVORABLE. THE INITIAL POSITION WAS 
BASED ON THE AFOREMENTIONED SSMIS IMAGE. THE INITIAL INTENSITY WAS 
BASED ON PGTW AND RJTD DVORAK ESTIMATES OF 25 KNOTS. TD 05W IS 
CURRENTLY TRACKING ALONG THE SOUTHWESTERN PERIPHERY OF A LOW- TO MID-
LEVEL SUBTROPICAL STEERING RIDGE.
3. FORECAST REASONING.
   A. THIS FORECAST REASONING HAS NOT CHANGED SINCE THE PREVIOUS 
PROGNOSTIC REASONING BULLETIN.
   B. TD 05W IS EXPECTED TO CONTINUE TRACKING GENERALLY NORTH-
NORTHWESTWARD OVER THE NEXT 12 HOURS AND THEN WILL BEGIN TURNING 
MORE POLEWARD AS AN APPROACHING MID-LATITUDE TROUGH WEAKENS THE 
STEERING RIDGE. TD 05W IS EXPECTED TO SLOWLY INTENSIFY BEFORE MAKING 
LANDFALL OVER CHINA AFTER TAU 36 AND DISSIPATE OVER LAND BY TAU 72. 
NUMERICAL MODEL GUIDANCE IS IN GOOD AGREEMENT, HOWEVER THERE IS SOME 
SPREAD IN THE TIMING OF RECURVATURE AND WBAR ERRONEOUSLY TRACKS THE 
SYSTEM WITH THE DEEP LAYER FLOW FARTHER NORTHWESTWARD. GFS IS 
QUICKEST TO RECURVE THE SYSTEM AS IT PREDICTS A DEEPER TROUGH TO 
MODIFY THE STEERING RIDGE MORE SIGNIFICANTLY. THIS FORECAST IS IN 
AGREEMENT WITH A SLOWER RECURVATURE. THE INTENSITY FORECAST IS 
SLIGHTLY HIGHER THAN GUIDANCE DUE TO FAVORABLE DIVERGENCE ALOFT AND 
WARM SEA SURFACE TEMPERATURES.//
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