WDPN32 PGTW 131500
MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI//
SUBJ/PROGNOSTIC REASONING FOR TYPHOON 15W (BOLAVEN) WARNING NR 027//
RMKS/
1. FOR METEOROLOGISTS.
2. 6 HOUR SUMMARY AND ANALYSIS.

SUMMARY:
   INITIAL POSITION: 29.5N 151.3E
   INITIAL INTENSITY: 100 KTS
   GEOGRAPHIC REFERENCE: 682 NM EAST-SOUTHEAST OF YOKOSUKA, JAPAN
   MOVEMENT PAST 6 HOURS: NORTHEASTWARD AT 32 KTS
   SIGNIFICANT WAVE HEIGHT: 48 FEET

SATELLITE ANALYSIS, INITIAL POSITION AND INTENSITY DISCUSSION:
ANIMATED ENHANCED INFRARED (EIR) SATELLITE IMAGERY SHOWS THE SYSTEM
CONTINUED TO SEVERELY ERODE AND ELONGATE AS IT ACCELERATED
NORTHEASTWARD DEEPER INTO THE STRONG PREVAILING WESTERLIES ON THE
POLEWARD SIDE OF THE STEERING RIDGE. A CLUSTER OF WARM PIXELS OF A
RECENTLY OBSCURED EYE IS STILL EVIDENT. THE INITIAL POSITION IS
PLACED WITH HIGH CONFIDENCE BASED ON THE REMNANT EYE IN THE EIR
LOOP. THE INITIAL INTENSITY OF 100KTS IS ALSO PLACED WITH HIGH
CONFIDENCE BASED ON THE HIGH END OF AGENCY AND AUTOMATED DVORAK 
ESTIMATES AND REFLECTS THE 6-HR RAPID DETERIORATION. ANALYSIS 
INDICATES A HIGHLY UNFAVORABLE ENVIRONMENT WITH THE STRONG POLEWARD 
OUTFLOW OFFSET BY INCREASING VWS, COOLING SST, AND DRY AIR INTRUSION 
AT THE LOWER LEVELS.

INITIAL WIND RADII BASIS: SCATTEROMETER DATA.

CURRENT STEERING MECHANISM: DEEP-LAYERED SUBTROPICAL RIDGE (STR) TO
THE SOUTHEAST.


AGENCY DVORAK AND AUTOMATED FIXES: 
   PGTW: T5.0 - 90 KTS
   RJTD: T6.0 - 115 KTS
   CIMSS ADT: 79 KTS AT 131130Z
   CIMSS D-PRINT: 87 KTS AT 131130Z

FORECASTER ASSESSMENT OF CURRENT ENVIRONMENT: HIGHLY UNFAVORABLE
   VWS: 20-25 KTS
   SST: 27-28 CELSIUS
   OUTFLOW: STRONG POLEWARD
   OTHER FACTORS: COLD DRY AIR INTRUSION FROM THE NORTHWEST THROUGH
WEST. 

ANALYSIS CONFIDENCE:
   INITIAL POSITION: HIGH
   INITIAL INTENSITY: HIGH
   INITIAL WIND RADII: HIGH

3. FORECAST REASONING.

SIGNIFICANT FORECAST CHANGES: THERE ARE NO SIGNIFICANT CHANGES TO
THE FORECAST FROM THE PREVIOUS WARNING.

FORECAST DISCUSSION: TYPHOON BOLAVEN WILL CONTINUE TO ACCELERATE
NORTHEASTWARD ON THE POLEWARD SIDE OF THE STR UNDER THE STRONG
WESTERLIES. THE HIGHLY UNFAVORABLE ENVIRONMENT WILL CONTINUE TO
RAPIDLY ERODE THE SYSTEM. CONCURRENTLY, TY 15W HAS ENTERED THE
BAROCLINIC ZONE AND BEGUN EXTRA-TROPICAL TRANSITION (ETT) AND BY
TAU 24, WILL COMPLETELY TRANSFORM INTO A 75-KNOT HURRICANE-FORCE
COLD-CORE LOW. 

MODEL DISCUSSION: NUMERICAL MODELS REMAIN IN VERY TIGHT AGREEMENT
WITH AN EVEN AND GRADUAL SPREAD TO A MERE 59NM BY TAU 24, LENDING
HIGH CONFIDENCE IN THE JTWC TRACK FORECAST. THERE IS ONLY MEDIUM
CONFIDENCE IN THE INTENSITY FORECAST GIVEN THE UNCERTAINTIES
TYPICAL WITH ETT.

FORECAST CONFIDENCE:
   TRACK 0 - 72 HR: HIGH
   INTENSITY 0 - 72 HR: MEDIUM//
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