WDPN32 PGTW 282100
MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI//
SUBJ/PROGNOSTIC REASONING FOR TYPHOON 09W (SAOLA) WARNING NR 021//
RMKS/
1. FOR METEOROLOGISTS.
2. 6 HOUR SUMMARY AND ANALYSIS.

SUMMARY:
   INITIAL POSITION: 18.3N 123.9E
   INITIAL INTENSITY: 100 KTS
   GEOGRAPHIC REFERENCE: 278 NM NORTHEAST OF MANILA, PHILIPPINES
   MOVEMENT PAST 6 HOURS: NORTH-NORTHWESTWARD AT 04 KTS
   SIGNIFICANT WAVE HEIGHT: 40 FEET

SATELLITE ANALYSIS, INITIAL POSITION, AND INTENSITY DISCUSSION:
ANIMATED PROXYVIS IMAGERY DEPICTS A MEDIUM-SIZED TYPHOON WITH
PERSISTENT CENTRALIZED CONVECTION AND CONVECTIVE BANDING, WHICH IS 
EVIDENT MOSTLY TO THE NORTH AND WEST OF THE SYSTEMS LLC. STRONG 
POLEWARD OUTFLOW IS OBSERVED IN THE CIRRUS CLOUD LAYER. BOTH 37GHZ AND
89GHZ GMI MICROWAVE IMAGES AT 281414Z NICELY CAPTURE WHAT APPEARS
TO BE AN EYEWALL REPLACEMENT CYCLE, WITH TWO DISTINCT EYEWALLS AND
A MOAT BETWEEN THEM. CIMSS MPERC PRODUCT HAD PROBABILITIES AS HIGH
AS 80 PERCENT AT 280600Z, AND SHOW NEAR REALTIME RING SCORES
ALLUDING TO AN EYEWALL REPLACEMENT CYCLE. THE INITIAL POSITION
IS PLACED WITH MEDIUM CONFIDENCE A 281800Z HM9 PROXYVIS IMAGE.
INITIAL INTENSITY OF 100 KTS IS ASSESSED WITH MEDIUM CONFIDENCE
BASED ON PERSISTENCE, MULTI-AGENCY DVORAK ESTIMATES (SUBJECTIVE),
AND CIMSS DPRINT INTENSITY ESTIMATE (OBJECTIVE).

INITIAL WIND RADII BASIS: PERSISTENCE 

CURRENT STEERING MECHANISM: SUBTROPICAL RIDGE TO THE NORTHEAST.

AGENCY DVORAK AND AUTOMATED FIXES: 
   PGTW: T6.0 - 115 KTS
   RJTD: T5.5 - 102 KTS
   KNES: T5.5 - 102 KTS
   CIMSS SATCON: 80 KTS AT 281713Z
   CIMSS ADT: 84 KTS AT 281730Z

FORECASTER ASSESSMENT OF CURRENT ENVIRONMENT: FAVORABLE
   VWS: 5-10 KTS
   SST: 29-30 CELSIUS
   OUTFLOW: STRONG POLEWARD

ANALYSIS CONFIDENCE:
   INITIAL POSITION: MEDIUM
   INITIAL INTENSITY: MEDIUM
   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 NORTHWESTWARD TOWARD THE
LUZON STRAIT UNDER THE STR, THEN WEST-NORTHWESTWARD TOWARD HONG
KONG AFTER TAU 48 AS THE STR BUILDS. FOLLOWING THE ONGOING EYEWALL
REPLACEMENT CYCLE, TY SAOLA IS FORECASTED TO REACH A PEAK INTENSITY
OF 115KTS BY TAU 24. AFTERWARD, INCREASING VWS AND LAND INTERACTION
WILL GRADUALLY WEAKEN THE SYSTEM DOWN TO 40KTS BY TAU 120 AS IT
MAKES LANDFALL IN THE VICINITY OF HONG KONG.

MODEL DISCUSSION: NUMERICAL MODELS ARE IN MODERATE AGREEMENT WITH
GFS AND NAVGEM OUTLYING THE CLUSTER SOUTH OF TRACK.  CROSS-TRACK
ERROR GROWS MARGINALLY FROM 80NM AT TAU 48 TO 213NM AT TAU 120.

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