WDPN32 PGTW 180300
MSGID/GENADMIN/NAVMARFCSTCEN PEARL HARBOR HI/JTWC//
SUBJ/PROGNOSTIC REASONING FOR TYPHOON 19W WARNING NR 14//
RMKS/
1. FOR METEOROLOGISTS.
2. 12 HOUR SUMMARY AND ANALYSIS.
   A. TYPHOON 19W (SONCA), LOCATED APPROXIMATELY 445 NM SOUTH-
SOUTHEAST OF TOKYO, JAPAN, HAS TRACKED NORTH-NORTHWESTWARD AT 13 
KNOTS OVER THE PAST SIX HOURS. MULTISPECTRAL SATELLITE IMAGERY (MSI) 
DEPICTS TIGHTLY CURVED BANDING WRAPPING INTO THE LOW LEVEL 
CIRCULATION CENTER. THE INITIAL POSITION IS BASED ON THE MSI IMAGERY 
WITH GOOD CONFIDENCE. A 172059Z SSMIS MICROWAVE IMAGE DEPICTS A 
SMALL EYE WITH DEEP CONVECTIVE BANDING ALONG THE SOUTHERN PERIPHERY 
AND MINIMAL CONVECTION TO THE NORTH. THE INITIAL INTENSITY IS BASED 
ON PGTW, KNES, AND RJTD DVORAK ESTIMATES RANGING FROM 55 TO 75 
KNOTS. WATER VAPOR IMAGERY AND THE CIMSS TOTAL PRECIPITABLE WATER 
PRODUCT SHOW DRY AIR SURROUNDING THE SYSTEM, ALTHOUGH A SMALL 
OUTFLOW CHANNEL STILL EXISTS TO THE SOUTHEAST. TY 19W IS QUICKLY 
TRACKING ALONG THE SOUTHWESTERN PERIPHERY OF A SUBTROPICAL STEERING 
RIDGE TO THE NORTHEAST.
3. FORECAST REASONING.
   A. THERE IS NO CHANGE TO THE FORECAST PHILOSOPHY SINCE THE 
PREVIOUS PROGNOSTIC REASONING BULLETIN.
   B. TY 19W WILL CONTINUE ROUNDING THE RIDGE AXIS OVER THE NEXT 24 
HOURS AND BEGIN INTERACTING WITH THE MID-LATITUDE WESTERLIES. TY 19W 
IS FORECAST TO INTENSIFY SLIGHTLY DUE TO IMPROVING OUTFLOW AND THEN 
BEGIN TO WEAKEN WITH DECREASING SEA SURFACE TEMPERATURES AND 
INCREASING VERTICAL WIND SHEAR. THE SYSTEM SHOULD COMPLETE EXTRA-
TROPICAL TRANSITION BY TAU 72. NUMERICAL MODEL GUIDANCE IS IN 
EXCELLENT AGREEMENT. THEREFORE, THIS FORECAST IS IN GOOD AGREEMENT 
WITH MODEL CONSENSUS.//
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