WDPN31 PGTW 020900
MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI//
SUBJ/PROGNOSTIC REASONING FOR TROPICAL STORM 11W (KIROGI) WARNING NR 
014//
RMKS/
1. FOR METEOROLOGISTS.
2. 6 HOUR SUMMARY AND ANALYSIS.

SUMMARY:
   INITIAL POSITION: 27.1N 146.2E
   INITIAL INTENSITY: 35 KTS
   GEOGRAPHIC REFERENCE: 928 NM EAST-SOUTHEAST OF SASEBO, JAPAN
   MOVEMENT PAST 6 HOURS: NORTHWESTWARD AT 21 KTS
   SIGNIFICANT WAVE HEIGHT: 16 FEET

SATELLITE ANALYSIS, INITIAL POSITION AND INTENSITY DISCUSSION:
ANIMATED MULTISPECTRAL SATELLITE IMAGERY (MSI) DEPICTS AN EXPOSED
LOW LEVEL CIRCULATION CENTER WITH ASSOCIATED, LIMITED DEEP
CONVECTION SHEARED SIGNIFICANTLY TO THE NORTH AND WEST BY THE FLOW
ASSOCIATED WITH AN UPPER LEVEL LOW TO THE WEST. THE INITIAL
POSITION IS PLACED WITH HIGH CONFIDENCE BASED ON THE EXPOSED CENTER
EVIDENT IN MSI. THE INITIAL INTENSITY OF 35 KTS IS ASSESSED WITH
MEDIUM CONFIDENCE, CONSERVATIVELY SET A BIT ABOVE SUBJECTIVE DVORAK
ESTIMATES OF T2.0 (30 KNOTS) BASED ON EXTRAPOLATION FROM EARLIER
SCATTEROMETER DATA AND A SUPPORTING CIMSS AIDT ESTIMATE OF 35 KTS
AT 020610Z.

INITIAL WIND RADII BASIS: PERSISTENCE AND OBJECTIVE BEST TRACK 

CURRENT STEERING MECHANISM: GRADIENT FLOW BETWEEN SUBTROPICAL
RIDGING TO THE EAST AND A DEEP TROUGH TO THE WEST.

AGENCY DVORAK AND AUTOMATED FIXES: 
   PGTW: T2.0 - 30 KTS
   RJTD: T2.0 - 30 KTS
   RCTP: T2.0 - 30 KTS
   KNES: T2.0 - 30 KTS
   CIMSS SATCON: 43 KTS AT 020309Z
   CIMSS ADT: 28 KTS AT 020540Z

FORECASTER ASSESSMENT OF CURRENT ENVIRONMENT: UNFAVORABLE
   VWS: 25-30 KTS
   SST: 28-29 CELSIUS
   OUTFLOW: MODERATE 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: TROPICAL STORM 11W WILL BEND WESTWARD OVER THE
NEXT 12 TO 24 HOURS AS IT CONTINUES TO FOLLOW THE FLOW BETWEEN
SUBTROPICAL RIDGING TO THE EAST AND NORTH AND A DEEP TROUGH TO THE
WEST AND SOUTH. THE SYSTEM WILL REMAIN IN A HOSTILE, SHEARED
ENVIRONMENT DUE TO PERSISTENCE OF THE UPPER LOW TO THE WEST AND
SOUTH OF THE SYSTEM THROUGHOUT THE FORECAST PERIOD. THE LOW LEVEL
CIRCULATION MAY TAKE SOME TIME TO SPIN DOWN, BUT DISSIPATION BY TAU
72 IS LIKELY.

MODEL DISCUSSION: CONSENSUS MODELS AND GLOBAL ENSEMBLE SOLUTION ARE
IN VERY GOOD AGREEMENT REGARDING THE OVERALL TRACK FORECAST
SCENARIO. SOLUTIONS DO BEGIN TO DIVERGE A BIT AROUND TAU 36, AND
INCREASINGLY TOWARD THE END OF THE FORECAST AT TAU 72. THIS SPREAD
IS ASSOCIATED WITH VARYING REPRESENTATIONS OF THE EVOLVING STEERING
FLOW SPEED AND THE STRUCTURE OF THE SYSTEM ITSELF. CONSIDERING
THESE FACTORS, FORECAST TRACK CONFIDENCE IS MEDIUM. REGARDING THE
INTENSITY FORECAST, THE LATEST COAMPS-TC RUN IS AN OUTLIER WITH A
PREDICTION OF POTENTIAL INTENSIFICATION AFTER TAU 24. HOWEVER,
ADDITIONAL MODEL GUIDANCE SUPPORTS THE DOWNWARD FORECAST TREND,
WHICH IS ALL BUT SET GIVEN OBSERVED AND EXPECTED SHEAR. FORECAST
INTENSITY CONFIDENCE IS HIGH.

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