WDPN32 PGTW 080900
MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI//
SUBJ/PROGNOSTIC REASONING FOR TROPICAL STORM 14W (MUIFA) 
WARNING NR 008//
RMKS/
1. FOR METEOROLOGISTS.
2. 6 HOUR SUMMARY AND ANALYSIS.

SUMMARY:
   INITIAL POSITION: 17.2N 131.9E
   INITIAL INTENSITY: 40 KTS
   GEOGRAPHIC REFERENCE: 603 NM SOUTH-SOUTHEAST OF KADENA AB
   MOVEMENT PAST 6 HOURS: WESTWARD AT 11 KTS
   SIGNIFICANT WAVE HEIGHT: 17 FEET

SATELLITE ANALYSIS, INITIAL POSITION AND INTENSITY DISCUSSION:
ANIMATED MULTISPECTRAL SATELLITE IMAGERY (MSI) DEPICTS THAT 14W HAS
PERSISTENT DEEP CONVECTIVE HOT TOWERS THAT ARE FIRING OFF AROUND
THE CORE OF THE CIRCULATION AND FULLY OBSCURING THE LLCC. A 080401Z
AMSR2 89GHZ COLOR COMPOSITE MICROWAVE IMAGE SHOWS THAT THE
CIRCULATION IS CONSOLIDATING AND FORMING DEEP CONVECTIVE ELEMENTS
IN ALL QUADRANTS OF THE CIRCULATION. THE INITIAL POSITION IS PLACED
WITH MEDIUM CONFIDENCE BASED ON MSI AND AMSR2 IMAGERY. THE INITIAL
INTENSITY OF 40 KTS IS ASSESSED WITH MEDIUM CONFIDENCE BASED ON A
RANGE OF DVORAK INTENSITY ESTIMATES SHOWING T2.0 - T3.5, WHILE
CIMSS ADT AND SATCON HOVER NEAR 35-40 KNOTS.

INITIAL WIND RADII BASIS: PERSISTENCE 

CURRENT STEERING MECHANISM: SUBTROPICAL RIDGES (STR) TO THE EAST
AND NORTH

AGENCY DVORAK AND AUTOMATED FIXES: 
   PGTW: T3.0 - 45 KTS
   RJTD: T2.0 - 30 KTS
   KNES: T3.5 - 55 KTS
   CIMSS SATCON: 41 KTS AT 080428Z
   CIMSS ADT: 34 KTS AT 080550Z

FORECASTER ASSESSMENT OF CURRENT ENVIRONMENT: FAVORABLE
   VWS: 0-5 KTS
   SST: 30-31 CELSIUS
   OUTFLOW: STRONG EQUATORWARD
   OTHER FACTORS: WEAK POLEWARD OUTFLOW INTO A TUTT CELL TO THE
NORTH

ANALYSIS CONFIDENCE:
   INITIAL POSITION: MEDIUM
   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: TS 14W IS CURRENTLY TRACKING GENERALLY
WESTWARD IN A FAVORABLE ENVIRONMENT CHARACTERIZED BY LOW VERTICAL
WIND SHEAR (0-5KTS), WARM SSTS (30-31C), AND GROWING OUTFLOW ALOFT.
OVER THE NEXT 12 HOURS, 14W IS FORECAST TO TURN GENERALLY
NORTHWESTWARD AS THE RIDGE TO THE EAST REORIENTS VERTICALLY, AT THE
SAME TIME THE SYSTEM WILL CONTINUE TO DEVELOP, CONSOLIDATE AND
INTENSIFY.  BY TAU 24 THE SYSTEM IS FORECAST TO REACH TYPHOON
STRENGTH AND CONTINUE DEEPENING THROUGH 48. BETWEEN TAU 48 AND TAU
72, THE SYSTEM WILL REACH ITS PEAK INTENSITY NEAR 110 KNOTS AND
POSSIBLY HIGHER, MEANWHILE, A VERY DEEP UPPER-LEVEL TROUGH MOVING
IN FROM THE WEST WILL REORIENT THE STEERING RIDGE PROVIDING A
DEFLECTION WESTWARD, MOVING 14W INTO THE PREVIOUS TRACK OF 12W.
THIS IS SIGNIFICANT BECAUSE OHC VALUES WILL PLUMMET TO BELOW 50
JOULES PER KG AND BEGIN TO OVERSHADOW THE FAVORABLE ENVIRONMENT 
LEADING TO A FAIRLY QUICK DROP IN INTENSITY. AFTER TAU 72, STILL WELL 
ABOVE TYPHOON STRENGTH 14W WILL CONTINUE TRACKING AROUND THE 
SOUTHWESTERN PERIPHERY OF THE STEERING RIDGE AND ENTER THE EAST CHINA 
SEA MOVING GENERALLY POLEWARD.


MODEL DISCUSSION: NUMERICAL MODELS ARE IN GOOD AGREEMENT ON THE
TRACK OF 14W, WITH A MAXIMUM SPREAD IN SOLUTIONS OF 100NM AT TAU
96. FOR THIS REASON THE JTWC TRACK FORECAST IS PLACED WITH HIGH
CONFIDENCE. RELIABLE MODEL INTENSITY GUIDANCE IS IN FAIR AGREEMENT
WITH HWRF TAKING AN EARLY AND HIGHLY AGGRESSIVE CLIMB TO 75 KNOTS
BY TAU 12 AND DECAY-SHIPS SHOWING A MUCH SLOWER TREND ONLY GETTING
TO AROUND 80 KNOTS BY TAU 72. THE BULK OF THE GUIDANCE, INCLUDING
SEVERAL RAPID INTENSIFICATION AIDS, INDICATES A MIDDLE GROUND WITH
AN INITIAL CLIMB TO AROUND 105-115 KNOTS BY TAU 72 AFTER WHICH ALL
MEMBERS EXCEPT COAMPS-TC TREND DOWNWARD. FOR THESE REASONS THE
INITIAL JTWC INTENSITY FORECAST IS PLACED WITH MEDIUM CONFIDENCE
AND THE EXTENDED INTENSITY FORECAST IS PLACED WITH LOW CONFIDENCE. 
 

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