WDPN31 PGTW 271500
MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI//
SUBJ/PROGNOSTIC REASONING FOR TYPHOON 05W (DOKSURI) WARNING NR 025//
RMKS/
1. FOR METEOROLOGISTS.
2. 6 HOUR SUMMARY AND ANALYSIS.

SUMMARY:
   INITIAL POSITION: 21.8N 119.2E
   INITIAL INTENSITY: 105 KTS
   GEOGRAPHIC REFERENCE: 235 NM SOUTH-SOUTHWEST OF TAIPEI, TAIWAN
   MOVEMENT PAST 6 HOURS: NORTHWARD AT 07 KTS
   SIGNIFICANT WAVE HEIGHT: 35 FEET

SATELLITE ANALYSIS, INITIAL POSITION AND INTENSITY DISCUSSION:
TYPHOON (TY) 05W (DOKSURI) HAS EMBARKED UPON ANOTHER ROUND OF
RAPID INTENSIFICATION OVER THE PAST SIX HOURS, AS IT PICKS UP SPEED
TOWARDS A RENDEZVOUS WITH THE CHINESE COAST. ANIMATED MULTISPECTRAL
SATELLITE IMAGERY (MSI) SHOWS THE SYSTEM HAS UNDERGONE WHAT IS
FRANKLY AN INCREDIBLE METAMORPHOSIS IN A VERY SHORT PERIOD OF TIME.
THE MSI SHOWS 6NM WIDE PINHOLE EYE, WHILE THE ENHANCED INFRARED
(EIR) IMAGERY SHOWS CLOUD TOP TEMPERATURES HAVE DRASTICALLY COOLED,
NOW APPROACHING -85C WHILE THE EYE TEMPERATURE IS NEAREST POSITIVE
TERRITORY. ANIMATED RADAR IMAGERY AND A 271005Z SSMIS 91GHZ
MICROWAVE IMAGE SHOW THE PINHOLE EYE WITH AN INNER EYEWALL AT ABOUT
6NM, SURROUNDED BY A MOAT OF CLEAR AIR AND A SECONDARY EYEWALL AT
ABOUT 50NM, WHICH IS STEADILY SHRINKING AS THE SYSTEM INTENSIFIES.
THE INITIAL POSITION IS ASSESSED WITH HIGH CONFIDENCE BASED THE EYE
FEATURE IN THE MSI, MICROWAVE AND RADAR IMAGERY. THE INITIAL
INTENSITY IS A BIT MORE TRICKY, WITH THE MAJORITY OF THE OBJECTIVE
ESTIMATES STILL TOO LOW AND PLAYING CATCH-UP, WHILE EVEN SOME OF
THE SUBJECTIVE ESTIMATES ARE LIKELY TOO LOW AS WELL. THUS THE
INTENSITY IS HEDGED UPWARDS TOWARDS THE PGTW T5.5 (102 KNOTS) AND
THE RAW ADT ESTIMATE OF T5.6, THOUGH CONFIDENCE IS LOW. CLEARLY THE
ENVIRONMENT IS SUPPORTIVE, WITH LOW SHEAR, ROBUST POLEWARD OUTFLOW
INTO AN UPPER-LEVEL LOW TO THE NORTH ADDING TO THE ALREADY STRONG
EQUATORWARD OUTFLOW. THE LATEST SST ANALYSIS FROM NOAA SHOWS THE
SYSTEM IS MOVING INTO AN AREA OF EXTREMELY WARM WATERS (31C) WITH
EVEN WARMER WATERS UP TO 32C ALONG THE COAST OF CHINA, LIKELY DUE
TO COASTAL DOWNWELLING INDUCED BY THE TYPHOON ITSELF.

INITIAL WIND RADII BASIS: PERSISTENCE 

CURRENT STEERING MECHANISM: WESTERN PERIPHERY OF A DEEP-LAYER
SUBTROPICAL RIDGE (STR) TO THE NORTHEAST. 

AGENCY DVORAK AND AUTOMATED FIXES: 
   PGTW: T5.5 - 102 KTS
   RJTD: T5.0 - 90 KTS
   RCTP: T5.5 - 102 KTS
   KNES: T5.0 - 90 KTS
   CIMSS ADT: 84 KTS AT 271130Z

FORECASTER ASSESSMENT OF CURRENT ENVIRONMENT: FAVORABLE
   VWS: 5-10 KTS
   SST: 30-31 CELSIUS
   OUTFLOW: STRONG POLEWARD AND EQUATORWARD

ANALYSIS CONFIDENCE:
   INITIAL POSITION: HIGH
   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: FROM THE LATEST RADAR DATA, IT APPEARS THAT TY
05W HAS FINALLY DECIDED TO GET A MOVE ON, AND ACCELERATED TOWARDS
THE NORTHWEST OVER THE PAST SIX HOURS. FURTHER ACCELERATION TOWARDS
THE COAST IS EXPECTED AS THE STR TO THE EAST BUILDS AND MOVES WEST,
TIGHTENING THE STEERING GRADIENT. LANDFALL IS STILL EXPECTED IN THE
VICINITY OF XIAMEN, CHINA WITHIN THE NEXT 12 TO 18 HOURS. AFTER
LANDFALL, THE SYSTEM WILL CONTINUE TO MOVE TO THE NORTH-NORTHWEST
THROUGH THE REMAINDER OF THE FORECAST, TO A POINT WEST OF SHANGHAI
WHERE IT IS EXPECTED TO DISSIPATE. AS DISCUSSED ABOVE, THE LATEST
SST ANALYSIS FROM NOAA AND CIMSS SUGGEST EXTREMELY WARM WATERS LIE
ALONG THE IMMEDIATE COAST OF EASTERN CHINA, INDUCED MOST LIKELY BY
THE COASTAL DOWNWELLING PROCESS AHEAD OF THE STORM. THE UPPER-LEVEL
LOW CURRENTLY SOUTHWEST OF SHANGHAI IS EXPECTED TO OPEN UP INTO A
TROUGH WHICH WILL EXTEND SOUTHWARD TO THE WEST OF TY 05W, WHICH
WILL ALLOW THE SYSTEM TO CONTINUE TAPPING INTO THE DIVERGENT
POLEWARD OUTFLOW ON THE EAST SIDE OF THE TROUGH. THE COMBINATION OF
CONTINUED STRONG OUTFLOW AND SCORCHING SSTS WILL SUPPORT ADDITIONAL
INTENSIFICATION IN THE PERIOD PRIOR TO LANDFALL. THE CURRENT
FORECAST CALLS FOR A PEAK OF 115 KNOTS, BUT A SLIGHTLY HIGHER PEAK
INTENSITY IS NOT OUT OF THE REALM OF POSSIBILITY IF THE EYEWALL
REPLACEMENT CYCLE (ERC) CAN FULLY COMPLETE PRIOR TO LANDFALL. 

MODEL DISCUSSION: TRACK GUIDANCE IS IN VERY TIGHT AGREEMENT, WITH
MINIMAL CROSS OR ALONG-TRACK SPREAD THROUGH LANDFALL AND ONLY A
MODEST AMOUNT OF ALONG-TRACK SPREAD THEREAFTER, LENDING HIGH
CONFIDENCE TO THE JTWC FORECAST TRACK. INTENSITY GUIDANCE IS
UNSURPRISINGLY IN POOR AGREEMENT THROUGH THE FIRST 12 TO 18 HOURS,
WITH THE MAJORITY OF THE CONSENSUS GUIDANCE INDICATING WEAKENING
FROM THE BEGINNING OF THE FORECAST. SOMEWHAT SURPRISING IS THE FACT
THAT DECAY-SHIPS (GFS) IS THE ONLY MODEL SHOWING SLIGHT
INTENSIFICATION THROUGH TAU 12. THE JTWC FORECAST DEVIATES HIGHER
THAN ALL THE GUIDANCE THROUGH TAU 12, THEN REJOINS THE PACK BY TAU
24, WITH MEDIUM CONFIDENCE THROUGH THE SHORT DURATION OF THE
FORECAST. 

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