WDPN32 PGTW 232100
MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI//
SUBJ/PROGNOSTIC REASONING FOR TROPICAL STORM 10W (FRANCISCO) WARNING 
NR 007//
RMKS/
1. FOR METEOROLOGISTS.
2. 6 HOUR SUMMARY AND ANALYSIS.

SUMMARY:
   INITIAL POSITION: 23.1N 128.2E
   INITIAL INTENSITY: 40 KTS
   GEOGRAPHIC REFERENCE: 205 NM SOUTH OF KADENA AB
   MOVEMENT PAST 6 HOURS: NORTHWESTWARD AT 14 KTS
   SIGNIFICANT WAVE HEIGHT: 20 FEET

SATELLITE ANALYSIS, INITIAL POSITION AND INTENSITY DISCUSSION:
TROPICAL STORM (TS) 10W REMAINS EMBEDDED WITHIN THE NORTHEASTERN
EDGE OF A LARGE, APPROXIMATELY 600NM DIAMETER LOW PRESSURE AREA AND
CYCLONIC GYRE. OVER THE NEXT 24 TO 48 HOURS, THIS AREA IS FORECAST
TO EXPAND EVEN MORE, AS TS 11W, CURRENTLY WEST OF LUZON, MOVES
NORTHEAST AND MERGES WITH THE REMNANTS OF TS 10W. ANIMATED TOTAL
PRECIPITABLE WATER (TPW) IMAGERY CONTINUES TO SHOW THE LARGE
EXPANSE OF DEEP SOUTHWESTERLIES EXTENDING FROM THE SOUTH CHINA SEA,
ACROSS THE PHILIPPINES AND PUSHING FAR INTO THE PHILIPPINE SEA,
WITH TS 11W AND TS 10W ROTATING CYCLONICALLY AROUND A CENTROID EAST
OF TAIWAN. OVERNIGHT ANIMATED ENHANCED INFRARED (EIR) SATELLITE
IMAGERY SHOWED THAT THE LOW LEVEL CIRCULATION CENTER (LLCC)
ASSOCIATED WITH TS 10W HAS SEPARATED FROM THE CONVECTIVE CDO AND
BECOME FULLY EXPOSED DUE TO PERSISTENT SOUTHWESTERLY SHEAR. A
231705 N20 ATMS 88GHZ MICROWAVE IMAGE REVEALED SHALLOW, FRAGMENTARY
BANDING ALONG THE SOUTHWESTERN PERIPHERY, WITH ISOLATED AND
FRAGMENTED CONVECTIVE BANDS DISPLACED WELL TO THE NORTHEAST. THE
INITIAL POSITION IS PLACED WITH HIGH CONFIDENCE BASED ON THE
EXPOSED LLCC. THE INITIAL INTENSITY IS ASSESSED WITH MEDIUM
CONFIDENCE, HEDGED SLIGHTLY HIGHER THAN THE BULK OF THE SUBJECTIVE
AND OBJECTIVE INTENSITY ESTIMATES. CONSISTENT WITH EARLIER
CHARACTERIZATION OF THE WIND FIELD, THE HIGHEST WINDS ARE ISOLATED
TO THE NORTH AND EASTERN HEMISPHERE OF THE SYSTEM. ENVIRONMENTAL
CONDITIONS ARE INCREASINGLY UNFAVORABLE, CURRENTLY ASSESSED AS
MARGINAL, WITH MODERATE SHEAR OFFSETTING THE STRONG POLEWARD AND
MODERATE EQUATORWARD OUTFLOW AND WARM SSTS.

INITIAL WIND RADII BASIS: SCATTEROMETER DATA AND PERSISTENCE. 

CURRENT STEERING MECHANISM: SUBTROPICAL RIDGE (STR) POSITIONED TO
THE EAST AND THE NORTH, AS WELL AS A LARGE CYCLONIC GYRE PATTERN,
WITH STRONG SOUTHWESTERLY FLOW EXTENDING FROM THE PHILIPPINES TO
THE NORTHEASTERN PHILIPPINE SEA. 

AGENCY DVORAK AND AUTOMATED FIXES: 
   PGTW: T3.0 - 45 KTS
   RJTD: T2.5 - 35 KTS
   RCTP: T2.5 - 35 KTS
   KNES: T3.5 - 55 KTS
   CIMSS SATCON: 42 KTS AT 231800Z
   CIMSS ADT: 41 KTS AT 231730Z
   CIMSS AIDT: 40 KTS AT 231730Z
   CIMSS D-MINT: 31 KTS AT 231641Z
   CIMSS D-PRINT: 31 KTS AT 231800Z

FORECASTER ASSESSMENT OF CURRENT ENVIRONMENT: MARGINAL
   VWS: 15-20 KTS
   SST: 29-30 CELSIUS
   OUTFLOW: MODERATE POLEWARD AND EQUATORWARD

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: TS 10W IS FORECAST TO TRACK
NORTH-NORTHWESTWARD, ALONG THE WESTERN AND SOUTHERN PERIPHERY OF
SUBTROPICAL RIDGING TO THE NORTH AND EAST, AS WELL AS AROUND THE
NORTHERN PERIPHERY OF THE LARGE CYCLONIC GYRE AND DEVELOPING
MONSOON DEPRESSION, THROUGH THE FORECAST PERIOD. THE SYSTEM HAS
REACHED PEAK INTENSITY AND IS FORECAST TO MAINTAIN ITS CURRENT
INTENSITY OF 40 KNOTS FOR ANOTHER 12 HOURS OR SO. AFTER PASSING
THROUGH THE MIYAKO STRAIT AND ENTERING THE EAST CHINA SEA, TS 10W
WILL BEGIN TO GRADUALLY WEAKEN AS IT MERGES WITH THE REMNANTS OF TS
11W APPROACHING FROM THE SOUTH AND DEVELOPS INTO A MONSOON
DEPRESSION TYPE SYSTEM. AN EXTENSIVE REGION OF GALE-FORCE WINDS IS
ANTICIPATED TO EXTEND OVER 160NM OUTWARD FROM THE CENTER, FOCUSED
IN THE EASTERN AND NORTHEASTERN QUADRANTS AS THE SYSTEM MOVES INTO
THE EAST CHINA SEA. TS 10W WILL RAPIDLY WEAKEN AFTER TAU 24 AS IT
MERGES INTO THE LARGER CYCLONIC CIRCULATION AND MONSOON DEPRESSION.
THE SYSTEM IS FORECAST TO DISSIPATE AS A DISTINCT TROPICAL CYCLONE
AS IT MERGES INTO THE LARGE CYCLONIC ROTATION, THOUGH WINDS ARE
EXPECTED TO REMAIN AROUND 30 KNOTS DURING THIS TRANSITION. ISOLATED
POCKETS OF GALE-FORCE WINDS COULD OCCUR IN FAVORED AREAS OF THE
NORTHERN TAIWAN STRAIT OR OFF THE NORTHEASTERN TIP OF TAIWAN DURING
THIS TIMEFRAME.   

MODEL DISCUSSION: DUE TO THE EXTREMELY COMPLEX AND CHALLENGING
SYNOPTIC SETUP, JTWC FORECAST CONFIDENCE REMAINS LOW. DETERMINISTIC
TRACK GUIDANCE IS IN GOOD AGREEMENT, AT LEAST FOR THE FIRST 24 TO
36 HOURS OF THE FORECAST. THE JTWC FORECAST LIES ON THE VERY
NORTHERN EDGE OF THE GUIDANCE ENVELOPE AND HEAVILY FAVORS THE
ECMWF, ECENS, EC-AIFS AND OTHER AI MODELS IN TRACKING A LOW-LEVEL
VORTICITY MAXIMUM IN THE FAR NORTHERN EDGE OF THE BROADER
CIRCULATION CENTER. SO FAR, THESE MODELS APPEAR TO BE INITIALIZING
THE BEST WHEN COMPARED TO THE SATELLITE DEPICTION. THE JTWC
FORECAST IS CONSISTENT WITH EARLIER FORECASTS, HOWEVER THE TRACK
HAS SHIFTED ABOUT 20NM SOUTHWARD, AWAY FROM OKINAWA, DUE TO RECENT
ADJUSTMENTS TO THE BEST TRACK POSITION AND THE CPA TO KADENA HAS
INCREASED TO 98NM. DUE TO THE BROAD NATURE OF THE SYSTEM AND THE
FORECASTED EVOLUTION AS IT PASSES THROUGH THE RYUKUS, SHIFTS IN THE
INITIAL POSITION AND TRACK ARE VERY LIKELY. INTENSITY GUIDANCE IS
IN STRONG AGREEMENT THAT THE SYSTEM WILL MAINTAIN INTENSITY IN THE
SHORT-TERM, THEN STEADILY WEAKEN THROUGH THE REMAINDER OF THE
FORECAST PERIOD.  

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