WDPN31 PGTW 221500
MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI//
SUBJ/PROGNOSTIC REASONING FOR TYPHOON 07W (MEKKHALA) WARNING NR 016//
RMKS/
1. FOR METEOROLOGISTS.
2. 6 HOUR SUMMARY AND ANALYSIS.

SUMMARY:
   INITIAL POSITION: 18.1N 126.1E
   INITIAL INTENSITY: 125 KTS
   GEOGRAPHIC REFERENCE: 513 NM SOUTH OF KADENA AB
   MOVEMENT PAST 6 HOURS: WEST-NORTHWESTWARD AT 08 KTS
   SIGNIFICANT WAVE HEIGHT: 50 FEET

SATELLITE ANALYSIS, INITIAL POSITION AND INTENSITY DISCUSSION:
ANIMATED ENHANCED INFRARED (EIR) SATELLITE IMAGERY DEPICTS TYPHOON
(TY) 07W (MEKKHALA) WITH A WELL-DEFINED AND SYMMETRICAL EYE
APPROXIMATELY 17NM IN DIAMETER WITH A CENTRAL EYE TEMPERATURE OF 15
C. 07W HAS CONTINUED TO RAPIDLY DEVELOP, INTENSIFYING 50 KTS IN 24
HOURS AND 70 KTS IN THE PAST 36 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: T6.5 - 127 KTS
   RJTD: T6.5 - 127 KTS
   RCTP: T6.5 - 127 KTS
   KNES: T6.5 - 127 KTS
   CIMSS ADT: 129 KTS AT 221300Z
   CIMSS AIDT: 124 KTS AT 221300Z
   CIMSS D-PRINT: 120 KTS AT 221300Z

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 HOURS WHILE IT REMAINS ON THE
SOUTHWESTERN EDGE OF THE EXTENSION FROM A STEERING STR. BETWEEN
TAU 12-24, 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 24. 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 SLIGHTLY SLOW ITS CURRENT
RATE OF INTENSIFICATION AND REACH ITS PEAK INTENSITY AT TAU 12 AT
130 KTS. A PEAK HIGHER THAN 130 KTS IS POSSIBLE AT TAU 24 IF 07W
CONTINUES TO RAPIDLY INTENSIFY AT THE CURRENT RATE OF
INTENSIFICATION. 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 STEADILY WEAKEN AS IT TRACKS FARTHER POLEWARD INTO THE
HIGHLY UNFAVORABLE ENVIRONMENT.

MODEL DISCUSSION: DETERMINISTIC MODEL TRACK GUIDANCE CONTINUES TO
BE IN STRONG AGREEMENT THROUGH TAU 72, EXCLUDING GSM, NAVGEM, AND
GALWEM. FOLLOWING TAU 72, SIGNIFICANT ALONG-TRACK SPREAD BEGINS TO
EMERGE AS MODELS STRUGGLE TO INTERPRET 07W ROUNDING THE EXTENSION.
EXCLUDING OUTLIERS, 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
AND THE FASTER EXPERIMENTAL AI CONSENSUS. RELIABLE INTENSITY
GUIDANCE IS IN MUCH BETTER AGREEMENT THAN PREVIOUS FORECASTS, WITH
ALL MODELS DEPICTING A PEAK INTENSITY AT TAU 12, FOLLOWED BY A
STEADY WEAKENING TREND. AS A RESULT, THE OFFICIAL JTWC INTENSITY
FORECAST IS ASSESSED WITH MEDIUM CONFIDENCE FROM TAU 0-72. 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//
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