WDPN32 PGTW 260300
MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI//
SUBJ/PROGNOSTIC REASONING FOR TYPHOON 09W (SAOLA) WARNING NR 010//
RMKS/
1. FOR METEOROLOGISTS.
2. 6 HOUR SUMMARY AND ANALYSIS.

SUMMARY:
   INITIAL POSITION: 18.4N 123.4E
   INITIAL INTENSITY: 100 KTS
   GEOGRAPHIC REFERENCE: 267 NM NORTH-NORTHEAST OF MANILA,
       PHILIPPINES
   MOVEMENT PAST 6 HOURS: SOUTHWARD AT 05 KTS
   SIGNIFICANT WAVE HEIGHT: 30 FEET

SATELLITE ANALYSIS, INITIAL POSITION AND INTENSITY DISCUSSION:
TYPHOON (TY) 09W HAS INTENSIFIED SLIGHTLY SINCE THE PREVIOUS JTWC
FORECAST WITH IMPROVED, MORE SYMMETRIC CORE CONVECTION. ANIMATED
MULTISPECTRAL SATELLITE IMAGERY (MSI) DEPICTS A CENTRAL DENSE
OVERCAST AND WHAT APPEARS TO BE A DEVELOPING EYE. RECENT ENHANCED
INFRARED SATELLITE IMAGERY HAD BRIEFLY DEPICTED A SMALL EYE (AND AN
UNOFFICIAL DVORAK ESTIMATE AS HIGH AS T5.5 (102 KNOTS)), HOWEVER,
THE EYE HAS YET TO MAINTAIN, LIKELY DUE TO UPWELLING COOLER WATER
AND MID-LEVEL DRY ENTRAINMENT AS SUGGESTED BY THE 251800Z HAFS-A
RUN. A 252244Z SSMIS COLOR COMPOSITE 91 GHZ MICROWAVE IMAGE DEPICTS
TIGHTLY CURVED BANDING WRAPPING INTO A MICROWAVE EYE FEATURE, WHICH
SUPPORTS THE INITIAL POSITION WITH HIGH CONFIDENCE. THE INITIAL
INTENSITY OF 100 KTS IS ASSESSED WITH MEDIUM CONFIDENCE BASED ON A
252146Z RCM-2 SAR IMAGE SHOWING MAXIMUM SUSTAINED WINDS OF 98 KNOTS. 
THIS ESTIMATE IS SLIGHTLY HIGHER THAN THE PGTW, KNES, RCTP DVORAK 
ESTIMATES AS WELL AS A 252247Z DMINT ESTIMATE OF 92 KNOTS. CIMSS ADT 
ESTIMATES HAVE REMAINED TOO LOW BUT HAVE STEADILY INCREASED OVER THE 
PAST SIX HOURS. ALL WIND RADII HAVE BEEN ADJUSTED BASED ON A DETAILED 
ANALYSIS OF THE RCM-2 SAR IMAGE.

INITIAL WIND RADII BASIS: SAR DATA 

CURRENT STEERING MECHANISM: SUBTROPICAL RIDGE (STR) POSITIONED TO
THE WEST.

AGENCY DVORAK AND AUTOMATED FIXES: 
   PGTW: T5.0 - 90 KTS
   RJTD: T4.5 - 77 KTS
   RCTP: T5.0 - 90 KTS
   KNES: T5.0 - 90 KTS
   CIMSS ADT: 82 KTS AT 252330Z

FORECASTER ASSESSMENT OF CURRENT ENVIRONMENT: FAVORABLE
   VWS: 15-20 KTS
   SST: 30-31 CELSIUS
   OUTFLOW: MODERATE RADIAL
   OTHER FACTORS: DYNAMIC OCEAN COOLING AND DRY AIR ENTRAINMENT

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

3. FORECAST REASONING.

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

FORECAST DISCUSSION: DESPITE THE POSSIBLE UPWELLING COOLER WATER
AND DRY AIR ENTRAINMENT, ENVIRONMENTAL CONDITIONS REMAIN FAVORABLE 
OVERALL WITH RADIAL OUTFLOW, LOW TO MODERATE VWS, WARM SST (30 C) AND 
HIGH OCEAN HEAT CONTENT VALUES. AS THE SYSTEM TRACKS SLOWLY SOUTHWARD 
OVER THE NEXT 24 HOURS, FURTHER DEVELOPMENT IS LIKELY, TEMPERED BY THE 
COOLER SST AND MID-LEVEL DRY AIR ENTRAINMENT ADVECTING OFF OF LUZON, 
WITH A PEAK OF 115 KNOTS ANTICIPATED NEAR TAU 12. FROM TAU 12 TO TAU 
36, TY 09W SHOULD WEAKEN SLIGHTLY AS IT STALLS EAST OF LUZON. AFTER TAU 
36, TY 09W WILL STEADILY INTENSIFY AS IT TRACKS POLEWARD. AFTER TAU 72, 
THE WESTERN STR WILL WEAKEN AND A STR IS EXPECTED TO BUILD TO THE 
NORTH, WHICH WILL DRIVE THE SYSTEM ONTO A NORTHWESTWARD TRACK TOWARD 
TAIWAN. ENVIRONMENTAL CONDITIONS WILL IMPROVE STEADILY ALLOWING THE 
SYSTEM TO REINTENSIFY TO A SECONDARY PEAK OF 130 KNOTS BY TAU 96.

MODEL DISCUSSION: DUE TO THE COMPLEX, EVOLVING STEERING PATTERN,
THERE IS MEDIUM OVERALL CONFIDENCE IN THE JTWC TRACK FORECAST. THE
251800Z EPS AND GEFS ENSEMBLES ALSO SUPPORT THE JTWC TRACK FORECAST
WITH MEDIUM CONFIDENCE. THE 251800Z COAMPS-TC ENSEMBLE SUPPORTS THE
SECONDARY REINTENSIFICATION PHASE AND SHOWS INCREASING RI
PROBABILITIES OF 40 TO 60 PERCENT IN THE TAU 60 TO TAU 90
TIMEFRAME. 

FORECAST CONFIDENCE:
   TRACK 0 - 72 HR: MEDIUM
   TRACK 72-120 HR: MEDIUM
   INTENSITY 0 - 72 HR: MEDIUM
   INTENSITY 72-120 HR: LOW//
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