WDPN32 PGTW 111500
MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI//
SUBJ/PROGNOSTIC REASONING FOR TYPHOON 14W (MUIFA) WARNING NR 021//
RMKS/
1. FOR METEOROLOGISTS.
2. 6 HOUR SUMMARY AND ANALYSIS.

SUMMARY:
   INITIAL POSITION: 23.3N 124.3E
   INITIAL INTENSITY: 105 KTS
   GEOGRAPHIC REFERENCE: 270 NM SOUTHWEST OF KADENA AB, OKINAWA,
JAPAN
   MOVEMENT PAST 6 HOURS: NORTHWARD AT 04 KTS
   SIGNIFICANT WAVE HEIGHT: 40 FEET

SATELLITE ANALYSIS, INITIAL POSITION AND INTENSITY DISCUSSION:
ANIMATED ENHANCED INFRARED (EIR) SATELLITE IMAGERY SHOWS A
MEDIUM-SIZED TYPHOON WITH A SYMMETRICAL DEEP CENTRAL CONVECTION THAT 
APPEARS TO BE WEAKENING AS IT IS UNDERGOING AN EYEWALL REPLACEMENT 
CYCLE AS EVIDENCED BY AN ENLARGING EYE. THE INITIAL POSITION IS PLACED 
WITH HIGH CONFIDENCE BASED ON THE EYE IN THE EIR LOOP THAT WAS 
CONCENTRIC WITH A WELL-DEFINED, ALBEIT ENLARGED CIRCULATION FEATURE IN 
THE COMPOSITE RADAR LOOP FROM JMA. THE INITIAL INTENSITY IS ALSO
PLACED WITH HIGH CONFIDENCE BASED ON EQUIVALENT AGENCY AND AUTOMATED 
DVORAK ESTIMATES AND REFLECTS THE 6-HR DEGRADATION. ANALYSIS INDICATES 
A MARGINALLY UNFAVORABLE ENVIRONMENT WITH STRONG OUTFLOW AND LIGHT VWS 
OFFSET BY COOLING SST DUE TO UPWELLING BROUGHT ON BY THE SLOW STORM 
MOTION.

INITIAL WIND RADII BASIS: PERSISTENCE.

CURRENT STEERING MECHANISM: DEEP-LAYERED SUBTROPICAL RIDGE (STR) TO
THE NORTHEAST. 

AGENCY DVORAK AND AUTOMATED FIXES: 
   PGTW: T5.5 - 102 KTS
   RJTD: T5.5 - 102 KTS
   KNES: T5.5 - 102 KTS
   CIMSS ADT: 107 KTS AT 111140Z

FORECASTER ASSESSMENT OF CURRENT ENVIRONMENT: MARGINALLY
UNFAVORABLE
   VWS: 5-10 KTS
   SST: 28-29 CELSIUS
   OUTFLOW: STRONG POLEWARD

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

3. FORECAST REASONING.

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

FORECAST DISCUSSION: A MIDLATITUDE SHORTWAVE TROUGH EXITING CHINA
VIA THE YELLOW SEA HAS WEAKENED THE STEERING STR AND ALLOWED THE
SYSTEM TO TRACK MORE NORTHWARD. BEHIND THE TROUGH, A SECONDARY STR
TO THE NORTHWEST IS COMPETING FOR STEERING CAUSING THE SYSTEM TO
SLOW DOWN. AFTER TAU 48, THE STR TO THE NORTHEAST WILL BUILD ANEW
AND REGAIN FULL STEERING AND ACCELERATE TY 14W NORTH-NORTHWESTWARD.
THE MARGINALLY UNFAVORABLE ENVIRONMENT WILL SLOWLY WEAKEN THE
SYSTEM DOWN TO 85KTS BY TAU 48. AFTERWARD, COOLING SST IN THE EAST
CHINA SEA AND INTO THE YELLOW SEA AND INCREASING VWS WILL ERODE THE
SYSTEM AT A MORE RAPID PACE AND BY TAU 120 TY 14W WILL BE REDUCED
TO 30KTS AS IT MAKES LANDFALL OVER NORTHEASTERN CHINA NEAR QINGDAO.

MODEL DISCUSSION: THE MAIN PACK OF NUMERICAL MODELS ARE IN TIGHT
AGREEMENT EVENLY SPREADING OUT TO 138NM BY TAU 72 THEN TO 400NM+ BY 
TAU 120. NVGM AND JGSM ARE THE LEFT AND RIGHT OUTLIERS OUTSIDE THE 
MAIN PACK. IN VIEW OF THIS, THERE IS MEDIUM CONFIDENCE IN THE JTWC 
TRACK AND INTENSITY FORECASTS, LAID CLOSE TO THE MODEL TRACK AND 
INTENSITY CONSENSUS, UP TO TAU 72 THEN LOW CONFIDENCE AFTERWARD.

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