WDPN32 PGTW 250900
MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI//
SUBJ/PROGNOSTIC REASONING FOR TYPHOON 09W (SAOLA) WARNING NR 007//
RMKS/
1. FOR METEOROLOGISTS.
2. 6 HOUR SUMMARY AND ANALYSIS.

SUMMARY:
   INITIAL POSITION: 19.7N 124.0E
   INITIAL INTENSITY: 65 KTS
   GEOGRAPHIC REFERENCE: 459 NM SOUTH-SOUTHWEST OF KADENA AB
   MOVEMENT PAST 6 HOURS: SOUTHWESTWARD AT 01 KTS
   SIGNIFICANT WAVE HEIGHT: 20 FEET

SATELLITE ANALYSIS, INITIAL POSITION AND INTENSITY DISCUSSION:
ANIMATED MULTISPECTRAL SATELLITE IMAGERY (MSI) DEPICTS A RAPIDLY
INTENSIFYING TYPHOON STRENGTH CIRCULATION. A GROWING CENTRAL DENSE
OVERCAST (CDO) IS FORMING OVER THE LLCC AS THE CORE OF THE
CIRCULATION CONTINUES TO CONSOLIDATE. CLOUD TOP TEMPERATURES HAVE
COOLED TO (-78C) AND AN EPHEMERAL WARMING SPOT NEAR THE CENTER,
FORESHADOWING A POSSIBLE EYE FORMING. A 250459Z AMSR2 89GHZ
MICROWAVE IMAGE REVEALS A NEARLY COMPLETE MICROWAVE EYE FEATURE AND
DEEP CONVECTION STILL ABSENT FROM THE NORTHWESTERN QUADRANT. A
250457Z AMSR2 SCALAR WIND PRODUCT, THOUGH LOW QUALITY, DOES
INDICATE 60-65KT WINDS WITHIN THE INNER MOST REGION OF THE
CIRCULATION AND 70KT WINDS WITHIN THE DEEPEST CONVECTION AND
THEREFOR LIKELY CONTAMINATED. THE INITIAL POSITION IS PLACED WITH
MEDIUM CONFIDENCE BASED ON MSI AND AMSR2 IMAGERY. THE INITIAL
INTENSITY OF 65 KTS IS ASSESSED WITH MEDIUM CONFIDENCE BASED ON
AMSR2 WIND SPEED DATA ALONG WITH PGTW DVORAK INTENSITY ESTIMATES
AND CIMSS DPRINT ALL INDICATING 65KTS WHILE RJTD, KNES AND VARIOUS
DIFFERENT AUTOMATED INTENSITY ESTIMATES REPORT SLIGHTLY HIGHER OR
LOWER ESTIMATES RANGING FROM 55-74KTS.

INITIAL WIND RADII BASIS: PERSISTENCE 

CURRENT STEERING MECHANISM: SUBTROPICAL RIDGE (STR) TO THE WEST,
CENTERED NEAR HONG KONG. 

AGENCY DVORAK AND AUTOMATED FIXES: 
   PGTW: T4.0 - 65 KTS
   RJTD: T3.5 - 55 KTS
   KNES: T4.5 - 77 KTS
   CIMSS SATCON: 67 KTS AT 250400Z
   CIMSS ADT: 74 KTS AT 250630Z

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

ANALYSIS CONFIDENCE:
   INITIAL POSITION: MEDIUM
   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 FORECAST TO INCREASE
EQUATORWARD TRACK SPEED OVER THE COMING HOURS, UNDER THE STEERING
INFLUENCE OF THE STR TO THE WEST. OVER THE NEXT 36 HOURS, 09W WILL
PROCEED GENERALLY EQUATORWARD UNTIL ITS FORWARD PROGRESS IS HALTED
BY A NEAR EQUATORIAL RIDGE (NER) TO THE SYSTEMS SOUTH. BY TAU 48,
09W WILL EXECUTE A GRACEFUL EASTWARD AND EVENTUALLY NORTHWARD
COURSE CHANGE. POTENTIAL INTERACTION WITH A VERY LARGE TROPICAL
CYCLONE NORTH OF GUAM, IF IT ACTUALLY DEVELOPS, WILL HAVE A
SIZEABLE IMPACT ON THE EXACT EXTENDED TRACK FORECAST OF 09W. IF THE
NEW SYSTEM DOES DEVELOP, THEN THE TRACK WILL LIKELY PUSH THROUGH
THE LUZON STRAIT. IF IT DOES NOT DEVELOP OR IS WEAKER THAN SEVERAL
DETERMINISTIC MODELS INDICATE, THIS WOULD LEAD TO A TRACK FURTHER
TOWARDS THE NORTH. IN TERMS OF INTENSITY, 09W IS FORECAST TO
QUICKLY INTENSIFY TO 100KTS BY TAU 36, AS THE SYSTEM EXECUTES THE
SHARP NORTHWARD TURN, THERE IS POTENTIAL FOR COOLER WATER TO BE
UPWELLED BENEATH THE SYSTEM, RESULTING IN A SOMEWHAT FLATTENED
INTENSITY TREND. THIS STAGNATION, HOWEVER IS QUICKLY RESOLVED AS
POLEWARD TRACK MOVEMENT IS ONCE AGAIN ACHIEVED. THE SYSTEM IS
FORECAST TO REACH A PEAK INTENSITY AT THE END OF THE CURRENT
FORECAST PERIOD IN THE NEIGHBORHOOD OF 120KTS AND POSSIBLY HIGHER.

MODEL DISCUSSION: NUMERICAL MODELS ARE IN GOOD AGREEMENT WITH ALL
MEMBERS GENERALLY FOLLOWING THE JTWC FORECAST TRACK THOUGH TAU 72.
AFTER TAU 72 HOWEVER, CROSS TRACK SPREADING INCREASES AS VARIOUS
MEMBERS ATTEMPT TO ACCOUNT FOR THE AFOREMENTIONED POTENTIAL VERY
LARGE TROPICAL CYCLONE THAT MAY FORM IN THE PHILIPPINE SEA. FOR
THESE REASONS THE JTWC TRACK FORECAST IS PLACED INITIALLY WITH
MEDIUM CONFIDENCE AND WITH LOW CONFIDENCE THERE AFTER. RELIABLE
MODEL INTENSITY GUIDANCE IS IN FAIR AGREEMENT WITH ALL MEMBERS
REFLECTING A SHARP INTENSIFICATION TREND THROUGH TAU 24 WITH A MORE
GRADUAL INCREASE THROUGH TAU 48. AFTER TAU 48 GENERAL STAGNATION
AND EVENTUALLY RENEWED INTENSIFICATION THROUGH THE FORECAST PERIOD.
WHILE THE JTWC INTENSITY TREND IS ECHOED BY A VAST MAJORITY OF THE
MEMBERS, THERE IS A ROUGHLY 25-30KT SPREAD IN THE GUIDANCE BY TAU
120. FOR THESE REASON THE JTWC INTENSITY FORECAST IS PLACED WITH
OVERALL MEDIUM CONFIDENCE.  

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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