WDPN31 PGTW 220300
MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI//
SUBJ/PROGNOSTIC REASONING FOR TYPHOON 07W (MEKKHALA) WARNING NR 014//
RMKS/
1. FOR METEOROLOGISTS.
2. 6 HOUR SUMMARY AND ANALYSIS.

SUMMARY:
   INITIAL POSITION: 17.5N 127.8E
   INITIAL INTENSITY: 100 KTS
   GEOGRAPHIC REFERENCE: 540 NM SOUTH OF KADENA AB
   MOVEMENT PAST 6 HOURS: WESTWARD AT 11 KTS
   SIGNIFICANT WAVE HEIGHT: 44 FEET

SATELLITE ANALYSIS, INITIAL POSITION AND INTENSITY DISCUSSION:
TYPHOON (TY) 07W HAS RAPIDLY INTENSIFIED 40 KNOTS OVER THE PAST 24
HOURS FROM 60 KNOTS AT 210000Z TO THE CURRENT INTENSITY OF 100
KNOTS. THE INITIAL POSITION IS PLACED WITH HIGH CONFIDENCE AS TY
07W (MEKKHALA) HAS DEVELOPED A PERSISTENT 15NM DIAMETER EYE VISIBLE
IN ANIMATED MULTISPECTRAL SATELLITE IMAGERY. A BULLSEYE 220013Z
METOP-B ASCAT PASS FURTHER SUPPORTS THE INITIAL POSITION AS WELL AS
LENDS SUPPORT TO THE HIGH CONFIDENCE ASSESSMENT OF THE INITIAL WIND
RADII. THE INITIAL INTENSITY IS ASSESSED WITH HIGH CONFIDENCE BASED
ON THE AGENCY DVORAK FIXES. ADDITIONALLY, THE UPDATED 220200Z CIMSS
OBJECTIVE ESTIMATES HAVE INCREASED TO 98-109 KNOTS AND THE 220230Z
PGTW FIX IS UP TO A T6.0 (115 KNOTS). ENVIRONMENTAL ANALYSIS
REVEALS FAVORABLE CONDITIONS OF LOW TO MODERATE (15-20 KTS)
VERTICAL WIND SHEAR (VWS), WARM (29-30 C) SEA SURFACE TEMPERATURES
(SSTS), AND STRONG RADIAL OUTFLOW ALOFT.

INITIAL WIND RADII BASIS: WIND RADII ADJUSTED BASED ON BULLSEYE
220013Z METOP-B ASCAT PASS.

CURRENT STEERING MECHANISM: SUBTROPICAL RIDGE (STR) CENTERED TO THE
NORTHEAST.

AGENCY DVORAK AND AUTOMATED FIXES: 
   PGTW: T5.5 - 102 KTS
   RJTD: T5.5 - 102 KTS
   RCTP: T5.0 - 90 KTS
   KNES: T5.5 - 102 KTS
   CIMSS ADT: 82 KTS AT 220000Z
   CIMSS AIDT: 86 KTS AT 220000Z
   CIMSS D-MINT: 93 KTS AT 212139Z
   CIMSS D-PRINT: 84 KTS AT 220000Z

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: HIGH
   INITIAL WIND RADII: HIGH

3. FORECAST REASONING.

SIGNIFICANT FORECAST CHANGES: THE PEAK INTENSITY AT TAU 24 HAS
INCREASED BY 20 KTS FROM THE PREVIOUS FORECAST TO 135 KTS.

FORECAST DISCUSSION: TY 07W IS FORECAST TO TRACK WEST-NORTHWESTWARD
UNDER THE STEERING INFLUENCE OF A SUBTROPICAL RIDGE (STR) CENTERED
TO THE NORTHEAST OF THE SYSTEM FOR THE NEXT 24 HOURS. PAST TAU 24,
THE SYSTEM IS EXPECTED TO TURN POLEWARD AS THE STR WEAKENS TO THE
NORTH OF TY 07W, ALSO SLOWING THE TRACK SPEED AS STEERING INFLUENCE
RECEDES. AT TAU 48, TY 07W IS FORECAST TO TURN NORTH-NORTHEASTWARD,
SLIGHTLY WEST OF OKINAWA AND ONWARDS TOWARD SOUTHERN KYUSHU. TY
MEKKHALA IS ASSESSED AS CURRENTLY UNDERGOING RAPID INTENSIFICATION
(RI) WHICH IS EXPECTED TO CONTINUE FOR THE NEXT 24 HOURS, REACHING
SUPERTYPHOON INTENSITY AT TAU 24. BEYOND THIS POINT, TY 07W IS
EXPECTED TO SLOW IN TRACK SPEED AS IT TURNS POLEWARD AND STEADILY
WEAKEN AS IT ENCOUNTERS A HOSTILE ENVIRONMENT OF OVER 30 KTS VWS,
DRY AIR, AND COOLER SSTS UPWELLED BY THE SLOWING OF STORM MOTION.
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.
AT TAU 120, TY 07W IS FORECAST TO BEGIN EXTRATROPICAL TRANSITION
(ETT) AS IT WILL BEGIN TO INTERACT WITH THE UPPER LEVEL WESTERLIES.

MODEL DISCUSSION: FORECAST TRACK MODEL GUIDANCE CONTINUES TO BE IN
GOOD AGREEMENT WITH THE EXCEPTION OF JGSM, NAVGEM, AND GALWEM NOT
PREDICTING THE NNE TURN. RUNNING A CONSENSUS EXCLUDING THESE THREE
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 TH 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 OUT TO TAU 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//
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