WDPN32 PGTW 231500
MSGID/GENADMIN/NAVMARFCSTCEN PEARL HARBOR HI/JTWC//
SUBJ/PROGNOSTIC REASONING FOR TROPICAL STORM 13W WARNING NR 14//
RMKS/
1. FOR METEOROLOGISTS.
2. 12 HOUR SUMMARY AND ANALYSIS.
   A. TROPICAL STORM (TS) 13W (MALAKAS), LOCATED APPROXIMATELY 170 
NM SOUTH OF IWO TO, JAPAN, HAS TRACKED NORTHWARD AT 12 KNOTS 
OVER THE PAST SIX HOURS. ANIMATED INFRARED SATELLITE IMAGERY SHOWS A 
BANDING EYE FEATURE WITH CONVECTION RE-BUILDING OVER THE SYSTEM 
CENTER. A 231021Z 37 GHZ SSMIS PASS AND A 231032Z 37 GHZ TRMM PASS 
DEPICT A FORMATIVE MICROWAVE EYE AND CONFIRM THE CURRENT POSITION 
WITH FAIR CONFIDENCE. THE CURRENT INTENSITY REMAINS AT 60 KNOTS 
BASED ON DVORAK ESTIMATES RANGING FROM 55 TO 65 KNOTS FROM PGTW, 
KNES, AND RJTD. UPPER LEVEL ANALYSIS INDICATES THE SUBSIDENCE 
PREVIOUSLY HINDERING CONVECTION ALONG THE WESTERN PERIPHERY OF THE 
SYSTEM HAS DECREASED ALLOWING FOR GOOD RADIAL OUTFLOW. TS 13W IS 
CURRENTLY TRACKING ALONG THE WESTERN PERIPHERY OF THE SUBTROPICAL 
STEERING RIDGE ANCHORED OVER THE NORTHERN PACIFIC.
3. FORECAST REASONING.
   A. THE FORECAST REASONING HAS NOT CHANGED SINCE THE PREVIOUS 
PROGNOSTIC REASONING BULLETIN.
   B. TS 13W IS FORECAST TO CONTINUE TRACKING POLEWARD AS IT ROUNDS 
THE RIDGE AXIS AND BEGINS TO INTERACT WITH THE STRONG BAROCLINIC 
ZONE TO THE NORTH. THE SYSTEM IS EXPECTED TO INTENSIFY THROUGH TAU 
36 DUE TO ENHANCED POLEWARD OUTFLOW INTO THE MID-LATITUDE 
WESTERLIES. DURING EXTRA-TROPICAL TRANSITION (ET), TS 13W IS 
EXPECTED TO REMAIN INTENSE, AS STRONG UPPER LEVEL DIFFLUENCE AND A 
SHARP TEMPERATURE GRADIENT ASSOCIATED WITH THE APPROACHING UPPER 
LEVEL TROUGH PROVIDE A STRONG BAROCLINIC DEVELOPMENT MECHANISM. TS 
13W IS EXPECTED TO COMPLETE ET BY TAU 72 AS AN INTENSE EXTRA-
TROPICAL LOW. NUMERICAL MODEL GUIDANCE REMAINS IN STRONG AGREEMENT; 
THEREFORE THIS FORECAST IS CLOSE TO MODEL CONSENSUS.//
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