WDPN31 PGTW 220900
MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI//
SUBJ/PROGNOSTIC REASONING FOR TYPHOON 07W (MEKKHALA) WARNING NR 015//
RMKS/
1. FOR METEOROLOGISTS.
2. 6 HOUR SUMMARY AND ANALYSIS.

SUMMARY:
   INITIAL POSITION: 17.9N 126.9E
   INITIAL INTENSITY: 115 KTS
   GEOGRAPHIC REFERENCE: 518 NM SOUTH OF KADENA AB
   MOVEMENT PAST 6 HOURS: WEST-NORTHWESTWARD AT 09 KTS
   SIGNIFICANT WAVE HEIGHT: 50 FEET

SATELLITE ANALYSIS, INITIAL POSITION AND INTENSITY DISCUSSION:
ANIMATED MULTISPECTRAL SATELLITE IMAGERY (MSI) DEPICTS TYPHOON (TY)
07W (MEKKHALA) WITH A WELL-DEFINED AND SYMMETRICAL EYE
APPROXIMATELY 10NM IN DIAMETER WITH A CENTRAL EYE TEMPERATURE OF 1
C. 07W HAS CONTINUED TO RAPIDLY DEVELOP, INTENSIFYING 50 KTS IN 24
HOURS. ENVIRONMENTAL ANALYSIS REVEALS HIGHLY FAVORABLE CONDITIONS
CHARACTERIZED BY LOW TO MODERATE (15-20 KTS) VERTICAL WIND SHEAR
(VWS), WARM (29-30 C) SEA SURFACE TEMPERATURES (SST), AND ROBUST
RADIAL OUTFLOW. THE INITIAL POSITION IS PLACED WITH HIGH CONFIDENCE
BASED ON THE WELL-DEFINED EYE IN ANIMATED MSI. THE INITIAL
INTENSITY OF 115 KTS IS ASSESSED WITH MEDIUM CONFIDENCE BASED ON
THE AGENCY DVORAK FIXES AND CIMSS INTENSITY ESTIMATES LISTED BELOW.

INITIAL WIND RADII BASIS: PERSISTENCE 

CURRENT STEERING MECHANISM: THE WESTWARD EXTENSION OF A SUBTROPICAL
RIDGE (STR) CENTERED TO THE NORTHEAST.

AGENCY DVORAK AND AUTOMATED FIXES: 
   PGTW: T6.0 - 115 KTS
   RJTD: T6.0 - 115 KTS
   RCTP: T5.0 - 90 KTS
   KNES: T6.0 - 115 KTS
   CIMSS SATCON: 119 KTS AT 220630Z
   CIMSS ADT: 117 KTS AT 220630Z
   CIMSS AIDT: 113 KTS AT 220630Z
   CIMSS D-MINT: 114 KTS AT 220518Z
   CIMSS D-PRINT: 114 KTS AT 220630Z

FORECASTER ASSESSMENT OF CURRENT ENVIRONMENT: HIGHLY FAVORABLE
   VWS: 15-20 KTS
   SST: 29-30 CELSIUS
   OUTFLOW: STRONG RADIAL

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: TY 07W IS FORECAST TO CONTINUE TRACKING
NORTH-NORTHWEST FOR THE NEXT 12-24 HOURS WHILE IT REMAINS ON THE
SOUTHWESTERN EDGE OF THE EXTENSION FROM THE STEERING STR. AROUND TAU
24, THE RIDGE EXTENSION IS EXPECTED TO WEAKEN AND RETREAT EASTWARD,
CAUSING 07W TO TRACK INTO A WEAKNESS IN THE RIDGE. MEKKHALA IS
EXPECTED TO SLOW ITS SPEED OF ADVANCE WHILE ROUNDING THE EXTENSION,
CROSSING THE RIDGE AXIS NO LATER THAN TAU 36. AFTER ROUNDING THE
RIDGE AXIS, MEKKHALA IS FORECAST TO TRACK NORTHEASTWARD THROUGH THE
END OF THE FORECAST PERIOD. AT AROUND TAU 120, 07W WILL BEGIN TO
INTERACT WITH THE BAROCLINIC ZONE AND THE POLAR FRONT JET, INDUCING
EXTRATROPICAL TRANSITION. 07W IS EXPECTED TO COMPLETE EXTRATROPICAL
TRANSITION BEYOND THE FORECAST PERIOD. REGARDING INTENSITY, 07W IS
FORECAST TO CONTINUE TO RAPIDLY INTENSIFY (RI) THROUGH TAU 12 AND
REACH ITS PEAK INTENSITY SHORTLY THEREAFTER AT TAU 24. AS 07W TURNS
NORTH WHILE ROUNDING THE RIDGE EXTENSION, IT WILL ENCOUNTER A
HOSTILE ENVIRONMENT CHARACTERIZED BY HIGH (35-40 KTS) VWS AND VERY
DRY AIR, WITH THE POSSIBILITY FOR FURTHER WEAKENING INDUCED BY THE
STORM'S COLD WAKE. MEKKHALA IS EXPECTED TO RAPIDLY WEAKEN AS IT
TRACKS FARTHER POLEWARD INTO THE HIGHLY UNFAVORABLE ENVIRONMENT.
HOWEVER, GLOBAL MODELS CONTINUE TO BE IN SOME DISAGREEMENT TO THE
SEVERITY AND ONSET TIME OF THESE DEGRADING ENVIRONMENTAL FACTORS,
WITH ECMWF BEING MUCH MORE AGGRESSIVE IN THE INCREASE IN VWS AND
DRY AIR WHEREAS GFS MAINTAINS LOWER VWS AND MORE MOIST AIR, THUS
PREDICTING TY 07W TO MAINTAIN TYPHOON LEVEL INTENSITIES FOR LONGER.

MODEL DISCUSSION: DETERMINISTIC MODEL TRACK GUIDANCE CONTINUES TO
BE IN STRONG AGREEMENT THROUGH TAU 72, EXCLUDING GSM AND NAVGEM.
FOLLOWING TAU 72, SIGNIFICANT ALONG-TRACK SPREAD BEGINS TO EMERGE
AS MODELS STRUGGLE TO INTERPRET 07W ROUNDING THE EXTENSION. RUNNING
A CONSENSUS EXCLUDING THE OUTLIER MODEL TRACKERS, THE OFFICIAL JTWC
FORECAST TRACK IS LAID WITH HIGH CONFIDENCE THROUGHOUT THE FORECAST
PERIOD, WITH AN ALONG TRACK SPEED THAT SPLITS THE DIFFERENCE
BETWEEN THE MULTI-MODEL CONSENSUS BEING SLOWED BY SOME OUTLIERS AND
THE NOTABLY FASTER EXPERIMENTAL AI CONSENSUS. FORECAST INTENSITY
MODEL GUIDANCE CONTINUES TO HAVE A LARGE SPREAD AT THE TIME OF PEAK
INTENSITY. THE OFFICIAL JTWC INTENSITY FORECAST IS ASSESSED WITH
MEDIUM CONFIDENCE FROM TAU 0-72 AS THE DEVELOPMENT OF A
WELL-DEFINED EYE WILL FURTHER STRENGTHEN THE SYSTEM IN THE SHORT
TERM. BEYOND TAU 72, THE OFFICIAL JTWC INTENSITY FORECAST IS
ASSESSED WITH LOW CONFIDENCE DUE TO SIGNIFICANT DISAGREEMENTS BETWEEN 
GLOBAL MODELS ON THE ENVIRONMENTAL CONDITIONS.

FORECAST CONFIDENCE:
   TRACK 00-72 HR: HIGH
   TRACK 72-120 HR: HIGH
   INTENSITY 00-72 HR: MEDIUM
   INTENSITY 72-120 HR: LOW//
NNNN