WDPN32 PGTW 010900
MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI//
SUBJ/PROGNOSTIC REASONING FOR TROPICAL DEPRESSION 11W (SHANSHAN) 
WARNING NR 041//
RMKS/
1. FOR METEOROLOGISTS.
2. 6 HOUR SUMMARY AND ANALYSIS.

SUMMARY:
   INITIAL POSITION: 33.8N 136.9E
   INITIAL INTENSITY: 25 KTS
   GEOGRAPHIC REFERENCE: 165 NM WEST-SOUTHWEST OF YOKOSUKA, JAPAN
   MOVEMENT PAST 6 HOURS: NORTHWARD AT 06 KTS
   SIGNIFICANT WAVE HEIGHT: 8 FEET

SATELLITE ANALYSIS, INITIAL POSITION AND INTENSITY DISCUSSION:
TROPICAL DEPRESSION 11W HAS RE-INTENSIFIED INTO A WEAK TROPICAL
DEPRESSION BASED ON A 010111Z ASCAT-C BULLSEYE IMAGE, WHICH SHOWS A
WELL-DEFINED CIRCULATION WITH A SWATH OF 25 KNOT WINDS OVER THE
EASTERN SEMI-CIRCLE. ANIMATED MULTISPECTRAL SATELLITE IMAGERY (MSI)
DEPICTS A FULLY-EXPOSED LOW-LEVEL CIRCULATION WITH ISOLATED DEEP
CONVECTION SHEARED TO THE NORTH. THE INITIAL POSITION IS PLACED
WITH HIGH CONFIDENCE BASED ON THE MSI. THE INITIAL INTENSITY OF 25
KTS IS ASSESSED WITH HIGH CONFIDENCE BASED ON THE AFOREMENTIONED
ASCAT DATA.

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

CURRENT STEERING MECHANISM: LOW- TO MID-LEVEL SUBTROPICAL RIDGE
POSITIONED TO THE EAST.

AGENCY DVORAK AND AUTOMATED FIXES: 
   PGTW: NO CURRENT ESTIMATE
   CIMSS ADT: 25 KTS AT 010220Z

FORECASTER ASSESSMENT OF CURRENT ENVIRONMENT: UNFAVORABLE
   VWS: 10-15 KTS
   SST: 29-30 CELSIUS
   OUTFLOW: WEAK POLEWARD AND EQUATORWARD

ANALYSIS CONFIDENCE:
   INITIAL POSITION: HIGH
   INITIAL INTENSITY: HIGH
   INITIAL WIND RADII: NOT APPLICABLE

3. FORECAST REASONING.

SIGNIFICANT FORECAST CHANGES: AVAILABLE METEOROLOGICAL DATA
SUPPORTS THE REGENERATION OF TD 11W, THEREFORE, JTWC IS RESUMING
WARNINGS. 

FORECAST DISCUSSION: TROPICAL DEPRESSION (TD) 11W IS TRACKING
POLEWARD ALONG THE NORTHWESTERN PERIPHERY OF A LOW- TO MID-LEVEL
SUBTROPICAL RIDGE POSITIONED TO THE EAST AND IS FORECAST TO MAKE
LANDFALL WITHIN THE NEXT THREE TO SIX HOURS. AFTER MAKING LANDFALL,
THE SYSTEM WILL STEADILY DECAY DUE TO FRICTIONAL EFFECTS WHILE 
RECURVING NORTHEASTWARD OVER THE JAPAN ALPS, WITH DISSIPATION 
EXPECTED BETWEEN TAU 12 AND TAU 24. 

MODEL DISCUSSION: NUMERICAL MODEL GUIDANCE IS IN FAIR AGREEMENT
WITH THE DETERMINISTIC GUIDANCE SUPPORTING THE JTWC TRACK FORECAST
WITH MEDIUM CONFIDENCE. THE 311800Z ECMWF ENSEMBLE (EPS) AND THE
010000Z GFS ENSEMBLE (GEFS) ALSO SUPPORT THE JTWC TRACK PHILOSOPHY.

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