WDPN33 PGTW 300300
MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI//
SUBJ/PROGNOSTIC REASONING FOR TROPICAL STORM 10W (HAIKUI) WARNING NR 
007//
RMKS/
1. FOR METEOROLOGISTS.
2. 6 HOUR SUMMARY AND ANALYSIS.

SUMMARY:
   INITIAL POSITION: 19.9N 136.2E
   INITIAL INTENSITY: 50 KTS
   GEOGRAPHIC REFERENCE: 408 NM SOUTHWEST OF IWO TO
   MOVEMENT PAST 6 HOURS: NORTHWESTWARD AT 05 KTS
   SIGNIFICANT WAVE HEIGHT: 23 FEET

SATELLITE ANALYSIS, INITIAL POSITION, AND INTENSITY DISCUSSION:
ANIMATED MULTISPECTRAL SATELLITE IMAGERY (MSI) DEPICTS DEEP
CONVECTION WAXING AND WANING OVER ALONG THE SOUTHERN PERIPHERY OF A
PARTIALLY EXPOSED LOW-LEVEL CIRCULATION. THE INITIAL POSITION IS
PLACED WITH MEDIUM CONFIDENCE BASED ON THE PARTIALLY-EXPOSED
CIRCULATION EVIDENT IN MSI AND 292151Z SSMIS MICROWAVE IMAGERY. THE
INITIAL INTENSITY OF 50 KTS IS ASSESSED WITH MEDIUM CONFIDENCE, SET
A BIT BELOW MULTI-AGENCY SUBJECTIVE DVORAK AND ADT VALUES
CONSISTENT WITH A BLEND OF ADDITIONAL OBJECTIVE INTENSITY
ESTIMATES, INCLUDING RECENT AIDT DATA IN THE 35-50 KNOT RANGE, AND
REFLECTING AN OBSERVED WEAKENING OF THE STORM STRUCTURE OVER THE
PAST SIX HOURS. TS 10W IS STRUGGLING A BIT TO ORGANIZE UNDER THE
INFLUENCE OF UNIDIRECTIONAL NORTH-NORTHEASTERLY FLOW ALOFT.

INITIAL WIND RADII BASIS: PERSISTENCE AND OBJECTIVE BEST TRACK 

CURRENT STEERING MECHANISM: SUBTROPICAL RIDGE (STR) TO THE NORTH

AGENCY DVORAK AND AUTOMATED FIXES: 
   PGTW: T3.5 - 55 KTS
   RJTD: T4.0 - 65 KTS
   RCTP: T3.5 - 55 KTS
   KNES: T3.5 - 55 KTS
   CIMSS ADT: 55 KTS AT 292340Z

FORECASTER ASSESSMENT OF CURRENT ENVIRONMENT: MARGINALLY FAVORABLE
   VWS: 10-15 KTS
   SST: 30-31 CELSIUS
   OUTFLOW: MODERATE WESTWARD

ANALYSIS CONFIDENCE:
   INITIAL POSITION: MEDIUM
   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: DESPITE ITS RECENT STRUGGLES, TS 10W IS
EXPECTED TO SLOWLY INTENSIFY UNDER MORE FAVORABLE UPPER-LEVEL
CONDITIONS OVER THE NEXT 24 HOURS AS IT CONTINUES TO TRACK
WEST-NORTHWESTWARD. AFTER TAU 24, PASSAGE OVER VERY WARM WATER AND
ADDITIONAL REORIENTATION OF THE UPPER-LEVEL FLOW PATTERN SHOULD
SUPPORT A FASTER INTENSIFICATION RATE, UNTIL ANOTHER INCREASE IN
VERTICAL WIND SHEAR AND PASSAGE NEAR LAND IN THE EXTENDED PERIOD
REVERSE THE TREND. THIS INTENSITY ASSESSMENT IS, OF COURSE,
DEPENDENT ON THE FORECAST TRACK. THE CURRENT ASSESSMENT ANTICIPATES
CONTINUED SMOOTH MOTION AROUND THE CURRENT STEERING RIDGE, WITH A
POLEWARD TURN ALONG THE EDGE OF THE RIDGE OCCURRING AFTER TAU 72.

MODEL DISCUSSION: THE MAIN GROUPING OF NUMERICAL MODEL SOLUTIONS
IS CONSISTENT WITH THE CURRENT FORECAST TRACK, DEPICTING A STEADY
TRACK ALONG THE SOUTHERN PERIPHERY OF THE STR FOR THE NEXT SEVERAL
DAYS FOLLOWED BY A POLEWARD TURN, WITH INCREASING SPREAD OVER TIME.
THE ECMWF DETERMINISTIC MODEL TRACKER, ECMWF ENSEMBLE MEAN, AND
JGSM SOLUTIONS LIE A BIT FARTHER TO THE NORTH OF THE PRIMARY MODEL
GROUPING, A SOLUTION ALSO SUPPORTED BY SOME MEMBERS OF THE GEFS
ENSEMBLE. ON THE OTHER HAND, THE NAVGEM AND GFS DETERMINISTIC
SOLUTIONS INDICATE A SLOWER AND SHARPER WESTWARD TRACK. THESE TWO
THESE SOLUTIONS ARE SUPPORTED BY ONLY A SMALL MINORITY OF AVAILABLE
GLOBAL MULTI-MODEL ENSEMBLE FORECASTS AND CONSIDERED LOW
PROBABILITY OUTCOMES AT THIS POINT. WHILE UNLIKELY, NORTHWARD
ADJUSTMENTS TO THE TRACK ORIENTATION IN SUBSEQUENT FORECASTS MAY BE
NECESSARY DEPENDING ON THE EVOLUTION OF THE STEERING PATTERN AND
DEPENDENT GUIDANCE.

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