WDPN32 PGTW 171500
MSGID/GENADMIN/NAVMARFCSTCEN PEARL HARBOR HI/JTWC//
SUBJ/PROGNOSTIC REASONING FOR TYPHOON 19W WARNING NR 12//
RMKS/
1. FOR METEOROLOGISTS.
2. 12 HOUR SUMMARY AND ANALYSIS.
   A. TYPHOON (TY) 19W (SONCA), LOCATED APPROXIMATELY 200 NM EAST-
NORTHEAST OF IWO TO, JAPAN, HAS TRACKED NORTHWESTWARD AT 17 KNOTS
OVER THE PAST SIX HOURS. ANIMATED INFRARED SATELLITE IMAGERY SHOWS
THE SYSTEM HAS FURTHER CONSOLIDATED AND WRAPPED TIGHTER INTO A 10-NM
RAGGED EYE. THIS IS ALSO EVIDENT ON A 171103Z METOPA MICROWAVE
IMAGE. THE INITAL POSITION IS BASED ON THE ABOVE ANIMATION AND
MICROWAVE IMAGE WITH HIGH CONFIDENCE. THE INITIAL INTENSITY IS
VALIDATED BY DVORAK ESTIMATES FROM PGTW, KNES, AND RJTD. UPPER LEVEL
ANALYSIS INDICATES THE SYSTEM IS BETWEEN TWO RIDGE AXES IN AN AREA
OF LOW TO MODERATE (10-20 KT) VERTICAL WIND SHEAR. TY 19W IS UNDER
THE STEERING INFLUENCE OF A DEEP-LAYERED SUBTROPICAL RIDGE TO THE
EAST. 
3. FORECAST REASONING.
   A. THERE IS NO CHANGE TO THE FORECAST PHILOSOPHY SINCE THE 
PREVIOUS PROGNOSTIC REASONING BULLETIN.
   B. TY SONCA IS EXPECTED TO ROUND THE WESTERN EDGE OF THE STEERING
RIDGE BEFORE RECURVING NORTHEASTWARD AFTER TAU 24 AND ACCELERATE
INTO EXTRA-TROPICAL TRANSITION. IT IS EXPECTED TO INTENSIFY SLIGHTLY
UP TO RECURVATURE DUE TO THE IMPROVING OUTFLOW ASSOCIATED WITH THE
STRONG WESTERLIES. THE SYSTEM WILL COMPLETE ET BY END OF FORECAST
PERIOD. AVAILABLE NUMERICAL GUIDANCE ARE IN EXCEPTIONALY TIGHT
AGREEMENT. THIS TRACK FORECAST IS SLIGHTLY TO THE LEFT OF AND FASTER
THAN CONSENSUS TO OFFSET KNOWN MODEL TENDENCY TO SLOW DOWN DURING
RECURVATURE.//
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