WDPN31 PGTW 301500
MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI//
SUBJ/PROGNOSTIC REASONING FOR TYPHOON 02W (MAWAR) WARNING NR 043//
RMKS/
1. FOR METEOROLOGISTS.
2. 6 HOUR SUMMARY AND ANALYSIS.

SUMMARY:
   INITIAL POSITION: 20.7N 125.0E
   INITIAL INTENSITY: 70 KTS
   GEOGRAPHIC REFERENCE: 380 NM SOUTH-SOUTHWEST OF KADENA AB, OKINAWA
   MOVEMENT PAST 6 HOURS: NORTHWARD AT 02 KTS
   SIGNIFICANT WAVE HEIGHT: 30 FEET

SATELLITE ANALYSIS, INITIAL POSITION AND INTENSITY DISCUSSION:
ANIMATED ENHANCED INFRARED (EIR) SATELLITE IMAGERY DEPICTS A SLIGHT
IMPROVEMENT IN CORE CONVECTION WITH DEEP CONVECTIVE BANDING
WRAPPING INTO A RAGGED CENTER. A 301129Z MHS 89GHZ MICROWAVE IMAGE,
HOWEVER, CONTINUES TO SHOW WEAK SPIRAL BANDING OVER THE NORTHERN
AND NORTHWESTERN QUADRANTS. THERE IS HIGH CONFIDENCE IN THE INITIAL
POSITION BASED ON THE EIR IMAGERY AND EXTRAPOLATION FROM AN EARLIER
300943Z SSMIS 91GHZ MICROWAVE IMAGE, WHICH SHOWED A DEFINED CENTER.
ENVIRONMENTAL CONDITIONS ARE MARGINAL DUE TO THE UPWELLING OF
COOLER WATER AND THE PRESENCE OF COOLER WATER (25-26C) OVER THE
EASTERN AND NORTHERN QUADRANTS. THE EYEWALL REPLACEMENT CYCLE (ERC)
APPEARS TO HAVE COMPLETED WITH NO EVIDENCE OF AN INNER EYEWALL AT
THIS TIME. THE INITIAL INTENSITY IS ASSESSED AT 70 KNOTS WITH
MEDIUM CONFIDENCE BASED ON THE RJTD AND KNES CURRENT INTENSITY
ESTIMATES AND THE CIMSS SATCON ESTIMATE AS WELL AS A 300858Z SMAP
IMAGE SHOWING MAXIMUM WINDS OF 72 KNOTS (1-MINUTE AVERAGE) OVER THE
EASTERN SEMICIRCLE. ADT, AIDT ESTIMATES APPEAR TO BE TOO LOW AND
INCONSISTENT WITH THE CONVECTIVE STRUCTURE BUT RECENT D-PRINT
(301200Z) AND D-MINT (300945Z) ESTIMATES OF 75 AND 76 KNOTS ALSO
SUPPORT THE INITIAL INTENSITY ASSESSMENT.

INITIAL WIND RADII BASIS: PERSISTENCE 

CURRENT STEERING MECHANISM: COMPETING STEERING PATTERN WITH A DEEP-
LAYER SUBTROPICAL RIDGE (STR) POSITIONED TO THE EAST AND ANOTHER STR 
ENTRENCHED OVER SOUTHEAST CHINA. 

AGENCY DVORAK AND AUTOMATED FIXES: 
   PGTW: T3.0 - 45 KTS
   RJTD: T4.5 - 77 KTS
   KNES: T4.5 - 77 KTS
   CIMSS SATCON: 74 KTS AT 301130Z
   CIMSS ADT: 57 KTS AT 301130Z

FORECASTER ASSESSMENT OF CURRENT ENVIRONMENT: MARGINAL
   VWS: 10-15 KTS
   SST: 28-29 CELSIUS
   OUTFLOW: MODERATE RADIAL
   OTHER FACTORS: COOL UPWELLING WATER

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

3. FORECAST REASONING.

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

FORECAST DISCUSSION: TY 02W IS EMBEDDED WITHIN A COMPETING STEERING
PATTERN WITH ZONAL 500MB FLOW PREVAILING TO THE NORTH OVER THE
KOREAN PENINSULA AND JAPAN. CONSEQUENTLY, THE SYSTEM HAS SLOWED AND
IS DRIFTING SLOWLY POLEWARD. DUE TO THE LACK OF A DYNAMIC MIDLATITUDE 
SHORTWAVE TROUGH TO ACCELERATE THE SYSTEM POLEWARD THROUGH TAU 72, 
TRACK SPEEDS ARE EXPECTED TO REMAIN CLIMATOLOGICALLY SLOW (LESS THAN 
7 KNOTS). TY 02W IS EXPECTED TO STEADILY WEAKEN THROUGH TAU 72 WITH 
COOLING SST AND DRY AIR ENTRAINMENT. AFTER TAU 72, AN APPROACHING 
MIDLATITUDE TROUGH WILL DIG TO THE NORTH ALLOWING THE SYSTEM TO 
GRADUALLY RECURVE AND ACCELERATE INTO THE SUBTROPICAL WESTERLIES. 
MORE SIGNIFICANT WEAKENING IS ANTICIPATED WITH COOLER SST (23-24C), 
DRY AIR ENTRAINMENT AND INCREASING VERTICAL WIND SHEAR. AFTER A SHORT 
PERIOD OF SUBTROPICAL TRANSITION, TY 02W IS EXPECTED TO UNDERGO 
EXTRA-TROPICAL TRANSITION AS IT APPROACHES THE KANTO PLAIN AFTER DAY 
5.      

MODEL DISCUSSION: DETERMINISTIC MODEL GUIDANCE REMAINS IN GOOD CROSS-
TRACK AGREEMENT WITH AN 80-100NM SPREAD IN SOLUTIONS THROUGH THE 
FORECAST PERIOD. HOWEVER, THERE IS A SIGNIFICANT, GROWING DIFFERENCE 
IN ALONG-TRACK SPEEDS WITH NAVGEM SLOWING TO A CRAWL AND THE JGSM AND 
AFUM TRACKERS RAPIDLY ACCELERATING NORTHEASTWARD. THE 300000Z ECMWF 
(EPS) AND GFS (GEFS) PROBABILISTIC GUIDANCE INDICATES A SIMILAR 
SPREAD OF GUIDANCE. OVERALL, THERE IS MEDIUM CONFIDENCE IN THE JTWC 
TRACK FORECAST THROUGH DAY 3 AND LOW CONFIDENCE AFTER DAY 3. IT IS 
WORTH NOTING THAT BOTH DETERMINISTIC AND PROBABILISTIC GUIDANCE 
INDICATE POTENTIAL FOR THE SYSTEM TO TRACK OVER OR CLOSE TO OKINAWA, 
AND REGARDLESS OF THE TRACK OVER OR TO THE EAST OF OKINAWA, THE 
SYSTEM IS STILL EXPECTED TO PRODUCE STORM-FORCE WINDS AS IT TRACKS 
NEAR THE RYUKYU ISLAND CHAIN.    

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