WDPN31 PGTW 021500
MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI//
SUBJ/PROGNOSTIC REASONING FOR TROPICAL DEPRESSION 11W (KIROGI) WARNING 
NR 015//
RMKS/
1. FOR METEOROLOGISTS.
2. 6 HOUR SUMMARY AND ANALYSIS.

SUMMARY:
   INITIAL POSITION: 28.6N 144.8E
   INITIAL INTENSITY: 30 KTS
   GEOGRAPHIC REFERENCE: 822 NM EAST-SOUTHEAST OF SASEBO, JAPAN
   MOVEMENT PAST 6 HOURS: NORTHWESTWARD AT 19 KTS
   SIGNIFICANT WAVE HEIGHT: 14 FEET

SATELLITE ANALYSIS, INITIAL POSITION AND INTENSITY DISCUSSION:
ANIMATED ENHANCED INFRARED (EIR) SATELLITE IMAGERY DEPICTS PATCHY,
DEEP CONVECTION FUELED BY NIGHTTIME COOLING ALOFT FLARING TO
THE EAST AND NORTH OF AN EXPOSED LOW-LEVEL CIRCULATION EVIDENT IN
021200Z PROXY VISIBLE IMAGERY FROM CIRA. THE INITIAL POSITION IS 
PLACED WITH HIGH CONFIDENCE ON AN EXPOSED LOW-LEVEL CENTER EVIDENT IN 
THE PROXY VISIBLE IMAGERY. THE INITIAL INTENSITY OF 30 KTS IS ASSESSED 
WITH MEDIUM CONFIDENCE BASED ON MULTIAGENCY SUBJECTIVE DVORAK CURRENT 
INTENSITY VALUES IN THE 25-30 KNOT RANGE AS WELL AS RECENT 28-KNOT 
ADT, 26-KNOT D-PRINT AND 27-KNOT D-MINT READINGS FROM UW-CIMSS. THE 
SYSTEM IS WEAKENING STEADILY UNDER THE INFLUENCE OF STRONG SOUTHERLY 
VERTICAL WIND SHEAR.

INITIAL WIND RADII BASIS: NOT APPLICABLE (THERE ARE NO INITIAL WIND
RADII).

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

AGENCY DVORAK AND AUTOMATED FIXES: 
   PGTW: T1.5 - 25 KTS
   RJTD: T2.0 - 30 KTS
   RCTP: T1.5 - 25 KTS
   KNES: T2.0 - 30 KTS
   CIMSS ADT: 28 KTS AT 021140Z

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: NOT APPLICABLE

3. FORECAST REASONING.

SIGNIFICANT FORECAST CHANGES: THERE ARE NO SIGNIFICANT CHANGES TO
THE FORECAST FROM THE PREVIOUS WARNING.

FORECAST DISCUSSION: TROPICAL DEPRESSION 11W WILL TURN WESTWARD OVER 
THE NEXT 12 TO 24 HOURS AS IT FOLLOWS THE FLOW BETWEEN SUBTROPICAL 
RIDGING TO THE EAST AND NORTH AND A DEEP TROUGH TO THE WEST AND SOUTH. 
STRONG VERTICAL WIND SHEAR DRIVEN BY AN UPPER LOW TO THE WEST AND 
SOUTH OF THE SYSTEM WILL DRIVE DISSIPATION BY TAU 48. DURING THIS 
PERIOD, TRANSIENT DEEP CONVECTION ASSOCIATED WITH THE CIRCULATION, 
SUPPORTED BY DIVERGENT FLOW ALOFT, WILL MOST LIKELY FLARE IN ZONES OF 
SURFACE CONVERGENCE TO THE NORTH AND EAST OF THE SYSTEM CENTER.

MODEL DISCUSSION: CONSENSUS MODELS AND GLOBAL ENSEMBLE SOLUTIONS
CONTINUE TO BROADLY SUPPORT KEY CHARACTERISTICS OF THE FORECAST
INCLUDING THE ANTICIPATED SMOOTH TURN TO A WESTWARD TRACK AND
STEADY DISSIPATION. TRACK SPREAD IS SMALL ON THIS RUN, SAVE THE
NAVGEM SOLUTION AND A FEW MULTI-MODEL ENSEMBLE MEMBERS THAT INDICATE A 
STALL AND RECURVATURE OF THE REMNANT CIRCULATION SOUTH OF HONSHU AFTER 
TAU 48 AND COAMPS-TC SOLUTIONS INDICATING THE POTENTIAL FOR LIMITED 
NEAR-TERM INTENSIFICATION. OUTLIER SOLUTIONS IN THE TRACK FORECAST AND 
RECENT MOTION POLEWARD OF CONSENSUS PREDICTIONS REDUCE CONFIDENCE IN 
THE TRACK FORECAST SLIGHTLY, BUT ONLY TO MEDIUM IN LIGHT OF THE 
RELATIVELY STRAIGHTFORWARD STEERING PATTERN AND SOLID MAJORITY OF 
CONSENSUS MEMBERS ALIGNED WITH THE FORECAST. A SCENARIO IN WHICH THE 
SYSTEM SURVIVES UNDER THE CONTINUED BOMBARDMENT OF VERTICAL WIND SHEAR 
IS DIFFICULT TO FATHOM, AND CONFIDENCE IN THE INTENSITY FORECAST IS
HIGH.

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