WDPN31 PGTW 261500
MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI//
SUBJ/PROGNOSTIC REASONING FOR TYPHOON 01W (EWINIAR) WARNING NR 
008//
RMKS/
1. FOR METEOROLOGISTS.
2. 6 HOUR SUMMARY AND ANALYSIS.

SUMMARY:
   INITIAL POSITION: 14.9N 122.3E
   INITIAL INTENSITY: 80 KTS
   GEOGRAPHIC REFERENCE: 761 NM SOUTH-SOUTHWEST OF KADENA AB,
OKINAWA
   MOVEMENT PAST 6 HOURS: NORTHEASTWARD AT 06 KTS
   SIGNIFICANT WAVE HEIGHT: 21 FEET

SATELLITE ANALYSIS, INITIAL POSITION AND INTENSITY DISCUSSION:
ANIMATED ENHANCED INFRARED (EIR) SATELLITE IMAGERY DEPICTS A CLEAR 4 
NM DIAMETER EYE FEATURE THAT HAS DEVELOPED DURING A PERIOD OF RAPID 
INTENSIFICATION OVER THE LAST SIX HOURS. TROCHOIDAL MOTION OF THE EYE 
WAS BRIEFLY EVIDENT IN EIR AS THE SYSTEM PASSED OVER POLILLO ISLAND, 
PHILIPPINES. WATER VAPOR IMAGERY DEPICTS STRONG EQUATORWARD AND 
POLEWARD OUTFLOW SUPPORTING INTENSIFICATION. THE INITIAL POSITION IS 
PLACED WITH HIGH CONFIDENCE BASED ON THE EYE FEATURE EVIDENT IN MSI, 
RADAR IMAGERY FROM THE PHILIPPINES, AND A 260956Z SSMIS 91GHZ IMAGE. 
THE INITIAL INTENSITY OF 80 KTS IS ASSESSED WITH MEDIUM CONFIDENCE, 
FAVORING HIGHER END AGENCY AND OBJECTIVE FIXES LISTED BELOW.

INITIAL WIND RADII BASIS: OBJECTIVE BEST TRACK AND PERSISTENCE 

CURRENT STEERING MECHANISM: A SUBTROPICAL RIDGE (STR) TO THE EAST

AGENCY DVORAK AND AUTOMATED FIXES: 
   PGTW: T4.0 - 65 KTS
   RJTD: T3.0 - 45 KTS
   RCTP: T4.0 - 65 KTS
   KNES: T5.0 - 90 KTS
   CIMSS ADT: 82 KTS AT 261300Z

FORECASTER ASSESSMENT OF CURRENT ENVIRONMENT: HIGHLY FAVORABLE
   VWS: 0-5 KTS
   SST: 30-31 CELSIUS
   OUTFLOW: STRONG POLEWARD AND EQUATORWARD

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 01W WILL CONTINUE TO TRACK NORTHEASTWARD
ALONG THE WESTERN PERIPHERY OF THE STR FOR THE REMAINDER OF THE
FORECAST PERIOD. TRACK SPEED WILL INCREASE AFTER 72 HOURS AS THE 
SYSTEM BEGINS TO MERGE WITH A MID-LATITUDE TROUGH. RAPID 
INTENSIFICATION IS EXPECTED TO OCCUR THROUGH THE NEXT 36 HOURS FUELED 
BY HIGH SEA SURFACE TEMPERATURES (SSTS), LOW VERTICAL WIND SHEAR, AND 
FAVORABLE UPPER-LEVEL DIVERGENCE. THE PEAK INTENSITY OF 120KTS IS 
SLIGHTLY HIGHER THAN THE PREVIOUS FORECAST PEAK DUE TO ONGOING RAPID 
INTENSIFICATION AND ASSOCIATED UPWARD SHIFTS IN THE NUMERICAL 
INTENSITY FORECAST GUIDANCE. AFTER TAU 72, INTERACTION WITH A MID-
LATITUDE TROUGH WILL INITIATE EXTRATROPICAL TRANSITION, WHICH WILL 
COMPLETE BY TAU 120. ELEVATED VWS AND COOL SSTS NORTH OF 26N WILL 
CONTINUE TO WEAKEN THE SYSTEM DURING EXTRATROPICAL TRANSITION, 
ALTHOUGH THE SYSTEM IS EXPECTED TO REINTENSIFY POST-TRANSITION DUE TO 
FAVORABLE BAROCLINIC INTERACTION WITH THE MID-LATITUDE TROUGH.

MODEL DISCUSSION: DETERMINISTIC TRACK GUIDANCE INDICATES MINIMAL
TRACK UNCERTAINTY AS TY 01W CONTINUES NORTHEASTWARD. AFTER TAU 60, 
TRACK CONFIDENCE DECREASES DUE TO VARYING MODEL REPRESENTATIONS OF 
INTERACTION BETWEEN THE STORM CIRCULATION AND THE APPROACHING MID-
LATITUDE TROUGH. PREVIOUS MODEL RUNS INCLUDED SOLUTIONS INDICATING A 
POSSIBLE DEVIATION NORTHWESTWARD FROM THE CONSENSUS TRACK TAKING THE 
SYSTEM CLOSER TO OKINAWA. HOWEVER, THE STRENGTH OF THAT SIGNAL HAS 
DECREASED IN THE MOST RECENT GUIDANCE PACKAGE. SPREAD IN THE 
INTENSITY GUIDANCE IS GREATEST BETWEEN TAU 24-48, WHEN TY 01W
IS EXPECTED TO PEAK. THE JTWC FORECAST FAVORS RAPID INTENSIFICATION 
REFLECTED IN THE MOST RECENT HAFS MESOSCALE MODEL FORECAST AND RAPID 
INTENSIFICATION AIDS TRIGGERING WITH HIGH PROBABILITIES THROUGH THE 
FIRST 36 HOURS. THE INTENSITY FORECAST ALIGNS CLOSELY WITH THE 
CONSENSUS GUIDANCE IN LATER TAUS. 

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