WDPN32 PGTW 281500
MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI//
SUBJ/PROGNOSTIC REASONING FOR TYPHOON 09W (SAOLA) WARNING NR 020//
RMKS/
1. FOR METEOROLOGISTS.
2. 6 HOUR SUMMARY AND ANALYSIS.

SUMMARY:
   INITIAL POSITION: 18.0N 124.1E
   INITIAL INTENSITY: 90 KTS
   GEOGRAPHIC REFERENCE: 271 NM NORTHEAST OF MANILA, PHILIPPINES
   MOVEMENT PAST 6 HOURS: NORTH-NORTHWESTWARD AT 05 KTS
   SIGNIFICANT WAVE HEIGHT: 48 FEET

SATELLITE ANALYSIS, INITIAL POSITION AND INTENSITY DISCUSSION:
ANIMATED ENHANCED INFRARED (EIR) SATELLITE IMAGERY SHOWS A
MEDIUM-SIZED SYMMETRICAL SYSTEM THAT HAS RECENTLY LOST ITS 14-NM
DIAMETER EYE AS THE CENTRAL CONVECTIVE TOPS AND THE EYEWALL HAVE
WARMED. THE INITIAL POSITION IS PLACED WITH HIGH CONFIDENCE BASED
ON THE RECENTLY CLOUD FILLED EYE. THE INITIAL INTENSITY OF 90 KTS
IS BASED WITH HIGH CONFIDENCE ON A 280937Z SMAP PASS AND REFLECTS
THE CONVECTIVE DETERIORATION. ANALYSIS INDICATES A FAVORABLE
ENVIRONMENT WITH VERY WARM SST IN THE PHILIPPINE SEA, STRONG
POLEWARD OUTFLOW ALOFT, OFFSET BY LOW TO MODERATE VWS.

INITIAL WIND RADII BASIS: SMAP DATA 

CURRENT STEERING MECHANISM: SUBTROPICAL RIDGE TO THE NORTHEAST.

AGENCY DVORAK AND AUTOMATED FIXES: 
   PGTW: T6.0 - 115 KTS
   RCTP: T6.5 - 127 KTS
   CIMSS ADT: 74 KTS AT 280830Z
   CIMSS D-PRINT: 87 KTS AT 281300Z

FORECASTER ASSESSMENT OF CURRENT ENVIRONMENT: FAVORABLE
   VWS: 15-20 KTS
   SST: 29-30 CELSIUS
   OUTFLOW: STRONG RADIAL

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

3. FORECAST REASONING.

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

FORECAST DISCUSSION: TY SAOLA WILL TRACK MORE NORTHWESTWARD TOWARD
THE LUZON STRAIT UNDER THE STR, THEN WEST-NORTHWESTWARD TOWARD HONG
KONG AFTER TAU 48 AS THE STR BUILDS. THE FAVORABLE ENVIRONMENT WILL
FUEL SLIGHT INTENSIFICATION TO A PEAK OF 105KTS AT TAU 24.
AFTERWARD, INCREASING VWS AND LAND INTERACTION WILL GRADUALLY
WEAKEN THE SYSTEM DOWN TO 30KTS BY TAU 120 AS IT MAKES LANDFALL
JUST EAST OF HONG KONG. 

MODEL DISCUSSION: NUMERICAL MODELS ARE IN OVERALL GOOD AGREEMENT
WITH A GRADUAL SPREAD TO 120NM AT TAU 72 THEN MORE SIGNIFICANTLY
TO 700+ NM AT TAU 120 WITH GFS AND NAVGM THE LEFT-OF-TRACK OUTLIERS
AND JGSM ON THE RIGHT MARGIN AND DRIVING THE VORTEX DIRECTLY
NORTHWARD INTO TAIWAN AFTER TAU 72. IN VIEW OF THESE, THERE IS
OVERALL MEDIUM CONFIDENCE IN THE JTWC TRACK FORECAST UP TO TAU 72
THEN LOW CONFIDENCE AFTERWARD.  

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