WDPN32 PGTW 122100
MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI//
SUBJ/PROGNOSTIC REASONING FOR TYPHOON 14W (MUIFA) WARNING NR 026//
RMKS/
1. FOR METEOROLOGISTS.
2. 6 HOUR SUMMARY AND ANALYSIS.

SUMMARY:
   INITIAL POSITION: 25.2N 124.0E
   INITIAL INTENSITY: 85 KTS
   GEOGRAPHIC REFERENCE: 219 NM WEST-SOUTHWEST OF KADENA
   MOVEMENT PAST 6 HOURS: NORTHWARD AT 02 KTS
   SIGNIFICANT WAVE HEIGHT: 36 FEET

SATELLITE ANALYSIS, INITIAL POSITION AND INTENSITY DISCUSSION:
ANIMATED ENHANCED INFRARED (EIR) SATELLITE IMAGERY DEPICTS 
SYMMETRIC DEEP CENTRAL CONVECTION AS THE SYSTEM HAS UNDERGONE A
EYEWALL REPLACEMENT CYCLE WITHIN THE LAST 6 HOURS. A 121725Z AMSR2
89GHZ MICROWAVE IMAGE SHOWS FORMATIVE CONVECTIVE BANDING IN ALL
QUADRANTS WRAPPING INTO THE LOW LEVEL CIRCULATION CENTER (LLCC),
WITH DEEP CONVECTIVE BANDING WRAPPING INTO THE NORTHEAST QUADRANT.
THE INITIAL POSITION IS PLACED WITH HIGH CONFIDENCE BASED ON EIR
IMAGERY WHICH SHOWS A DEFINITIVE EYE. THE INITIAL INTENSITY OF 85
KTS IS ASSESSED WITH MEDIUM CONFIDENCE BASED ON AN AVERAGE OF THE
DVORAK CURRENT INTENSITY ESTIMATES RANGING FROM 77 TO 92 KNOTS.

INITIAL WIND RADII BASIS: PERSISTENCE 

CURRENT STEERING MECHANISM: EXTENSION OF A DEEP-LAYER SUBTROPICAL
RIDGE (STR) TO THE NORTHEAST 

AGENCY DVORAK AND AUTOMATED FIXES: 
   PGTW: T5.0 - 90 KTS
   RJTD: T4.5 - 77 KTS
   CIMSS SATCON: 88 KTS AT 121800Z
   CIMSS ADT: 92 KTS AT 121930Z

FORECASTER ASSESSMENT OF CURRENT ENVIRONMENT: MARGINAL
   VWS: 10-15 KTS
   SST: 28-29 CELSIUS
   OUTFLOW: STRONG POLEWARD

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: THE PRIMARY STR REMAINS WEAK TO THE NORTHEAST
OF THE SYSTEM, DUE TO THE PRESENCE OF A DEVELOPING SYSTEM 16W TO
THE EAST. ADDITIONALLY, A BROAD 500MB UPPER-LEVEL TROUGH IS
POSITIONED OVER EASTERN CHINA EXTENDING SOUTHWARD, THESE FACTORS
COMBINED WILL ALLOW TY 14W TO SLOWLY TRACK POLEWARD. BY TAU 24, THE
SYSTEM WILL BEGIN TO TRACK SLOWLY NORTH-NORTHWESTWARD AND STEADILY
WEAKEN AS THE SYSTEM TRACKS WITHIN THE EASTERN PERIPHERY OF THE
UPPER-LEVEL. AFTER TAU 48, TY 14W MAKE LANDFALL OVER MAINLAND CHINA
AND WILL ACCELERATE AS IT TRACKS ALONG THE WESTERN PERIPHERY OF THE
PRIMARY STR WHILE ALSO INTERACTING WITH THE UPPER-LEVEL TROUGH.
RAPID WEAKENING WILL OCCUR AS THE SYSTEM CONTINUES JUST INLAND
ALONG THE EAST COAST OF CHINA FROM TAU 72 THROUGH TAU 96.       
 

MODEL DISCUSSION: NUMERICAL MODEL GUIDANCE IS IN GOOD AGREEMENT
THROUGH TAU 48 WITH ONLY A 140NM SPREAD IN SOLUTIONS BY TAU 48. BY
TAU 72 AND TAU 96 THE GUIDANCE SPREADS TO MORE THAN 400NM.
THEREFORE, THE JTWC TRACK FORECAST IS MEDIUM THROUGH TAU 72. THEN
LOW TRACK CONFIDENCE BY TAU 96 AS GUIDANCE DIVERGES WITH INCREASING
UNCERTAINTY. ADDITIONALLY, THE BULK OF THE ECMWF AND GFS ENSEMBLES
SUPPORT THE JTWC FORECAST TRACK TROUGH TAU 48, HOWEVER, BOTH
ENSEMBLE SOLUTIONS DIVERGE GREATLY WITH MANY  ECMWF MEMBERS TURNING
THE SYSTEM WESTWARD OVER MAINLAND CHINA, WHILE MANY OF THE GFS
ENSEMBLE SOLUTIONS SHOW THE POTENTIAL FOR A TURN BACK OVER THE
YELLOW SEA AFTER TAU 96 AND BEYOND. RELIABLE INTENSITY GUIDANCE IS
IN GOOD AGREEMENT WITH ALL MEMBERS SHOWING STEADY WEAKENING THROUGH
TAU 48, AFTER WHICH LAND INTERACTION AND EVENTUAL LANDFALL OCCURS
AND A SHARP DECREASE IN INTENSITY IS REFLECTED. ALTHOUGH, GIVEN THE
MODEL SPREAD AND THE POSSIBILITY OF THE SYSTEM MOVING BACK OVER
WATER, INTENSITY CONFIDENCE IS LOW BY THE END OF THE FORECAST.  


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