WDPN32 PGTW 290300
MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI//
SUBJ/PROGNOSTIC REASONING FOR TYPHOON 09W (SAOLA) WARNING NR 022//
RMKS/
1. FOR METEOROLOGISTS.
2. 6 HOUR SUMMARY AND ANALYSIS.

SUMMARY:
   INITIAL POSITION: 18.6N 123.5E
   INITIAL INTENSITY: 100 KTS
   GEOGRAPHIC REFERENCE: 280 NM NORTHEAST OF MANILA, PHILIPPINES
   MOVEMENT PAST 6 HOURS: NORTHWESTWARD AT 05 KTS
   SIGNIFICANT WAVE HEIGHT: 40 FEET

SATELLITE ANALYSIS, INITIAL POSITION, AND INTENSITY DISCUSSION:
OVER THE PAST SIX HOURS TYPHOON (TY) 09W HAS MAINTAINED AN OVERALL
SYMMETRIC CONVECTIVE CORE AS DEPICTED IN THE ANIMATED MULTISPECTRAL
SATELLITE IMAGERY. A 282205Z SSMIS 91 GHZ MICROWAVE IMAGE REVEALS A
SMALL MICROWAVE EYE, WHICH SUPPORTS THE INITIAL POSITION WITH HIGH
CONFIDENCE. ADDITIONALLY, THE INITIAL POSITION IS PLACED BASED
WITHIN A TIGHT GROUPING OF AGENCY POSITION FIXES. THE INITIAL
INTENSITY IS ASSESSED WITH MEDIUM CONFIDENCE BASED ON A COMBINATION
OF AGENCY DVORAK INTENSITY ESTIMATES BETWEEN T5.5 AND T6.0.
ENVIRONMENTAL CONDITIONS CONTINUE TO BE FAVORABLE FOR FURTHER
DEVELOPMENT WITH ENHANCED POLEWARD OUTFLOW, WARM (29-30 CELSIUS)
SEA SURFACE TEMPERATURES (SST), OFFSET BY MODERATE (10-15 KNOTS)
VERTICAL WIND SHEAR (VWS).

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
   RCTP: T6.0 - 115 KTS
   KNES: T5.5 - 102 KTS
   CIMSS ADT: 84 KTS AT 282330Z

FORECASTER ASSESSMENT OF CURRENT ENVIRONMENT: FAVORABLE
   VWS: 10-15 KTS
   SST: 29-30 CELSIUS
   OUTFLOW: MODERATE POLEWARD

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

3. FORECAST REASONING.

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

FORECAST DISCUSSION: TYPHOON 09W (SAOLA) IS FORECASTED TO TRACK
NORTHWESTWARD INTO THE LUZON STRAIT ALONG THE SOUTHWESTERN
PERIPHERY OF THE STR THROUGH TAU 36. AFTER TAU 36, TY 09W WILL
TRACK WEST-NORTHWESTWARD TOWARD SOUTHERN CHINA THROUGH TAU 120. THE
WESTERN EXTENT OF THE STR SHOULD REMAIN WEAK DUE TO THE PRESENCE OF
A BROAD UPPER LEVEL LOW OVER NORTHEAST ASIA. THEREFORE, TRACK
SPEEDS WILL REMAIN RELATIVELY SLOW THROUGH OUT THE FORECAST. IN
TERMS OF INTENSITY, THE FAVORABLE ENVIRONMENT WILL FUEL A SLIGHT
REINTENSIFICATION PHASE OVER THE NEXT 24 HOURS, AS THE SYSTEM
TRACKS AWAY FROM LUZON AND OVER WARMER SST. AFTERWARD, A SLIGHT
INCREASE VWS AND LAND INTERACTION WILL CAUSE 09W TO SLOWLY WEAKEN
IN THE EXTENDED FORECAST PERIOD.

MODEL DISCUSSION: NUMERICAL MODEL GUIDANCE IS IN FAIR AGREEMENT
THROUGH TAU 48 LENDING MEDIUM CONFIDENCE TO THE JTWC FORECAST
TRACK. AFTER TAU 48, TRACK GUIDANCE DIVERGES WITH A 370 NM SPREAD
IN SOLUTIONS BY TAU 120. WITH NVGM THE LEFT-OF-TRACK OUTLIER AND
ECMF ON THE RIGHT OF CONSENSUS TRACKING THE SYSTEM DIRECTLY
NORTH-NORTHWESTWARD INTO SOUTHERN CHINA BY TAU 120. ADDITIONALLY, LOW
TRACK CONFIDENCE AFTER TAU 48 IS REFLECTED IN THE 281800Z EPS AND
GEFS ENSEMBLES, WHICH SHOW A LARGE SPREAD. THE INTENSITY GUIDANCE
IS IN FAIR AGREEMENT AND SUPPORTS A STEADY INTENSIFICATION PHASE
WITH HAFS INDICATING A PEAK INTENSITY NEAR 115 KNOTS, JUST ABOVE
THE INTENSITY CONSENSUS PEAK OF 110 KNOTS. AFTER TAU 36 ALL MEMBERS
SHOW A STEADY DECREASE IN INTENSITY THROUGH THE FORECAST PERIOD. 

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