WDPN32 PGTW 012100
MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI//
SUBJ/PROGNOSTIC REASONING FOR TROPICAL STORM 19W (JEBI) WARNING NR 
022//
RMKS/
1. FOR METEOROLOGISTS.
2. 6 HOUR SUMMARY AND ANALYSIS.

SUMMARY:
   INITIAL POSITION: 39.1N 145.3E
   INITIAL INTENSITY: 60 KTS
   GEOGRAPHIC REFERENCE: 205 NM EAST-SOUTHEAST OF MISAWA, JAPAN
   MOVEMENT PAST 6 HOURS: NORTHEASTWARD AT 27 KTS
   SIGNIFICANT WAVE HEIGHT: 30 FEET

SATELLITE ANALYSIS, INITIAL POSITION AND INTENSITY DISCUSSION:
ANIMATED ENHANCED INFRARED (EIR) SATELLITE IMAGERY DEPICTS A STILL
NEARLY CIRCULAR CONVECTIVE CORE, AND A 1206Z ASCAT-C PASS SHOWED A
STILL COMPACT WIND FIELD. MODEL ANALYSES ALSO SHOW THAT THE STORM'S
WARM-CORED STRUCTURE REMAINS INTACT, SO THE CYCLONE CONTNIUES TO BE
ASSESSED AS TROPICAL. WIND SHEAR VALUES ARE QUICKLY INCREASING AS
19W NEARS THE MID-LATITUDE JET STREAM, AND THE STORM IS NOW
TRACKING OVER SIGNIFICANTLY COOLER WATERS NORTH OF THE KUROSHIO
CURRENT. THE INITIAL INTENSITY IS SET AT 60 KT BASED ON A BLEND OF
SCATTEROMETER DATA AND OBJECTIVE SATELLITE-BASED INTENSITY
ESTIMATES.

INITIAL WIND RADII BASIS: SCATTEROMETER DATA 

CURRENT STEERING MECHANISM: SUBTROPICAL RIDGE TO THE SOUTHEAST

AGENCY DVORAK AND AUTOMATED FIXES: 
   PGTW: T4.5 - 77 KTS
   RJTD: T4.0 - 65 KTS
   RCTP: T2.5 - 35 KTS
   KNES: T4.5 - 77 KTS
   CIMSS ADT: 55 KTS AT 011730Z

FORECASTER ASSESSMENT OF CURRENT ENVIRONMENT: UNFAVORABLE
   VWS: 20-25 KTS
   SST: 22-24 CELSIUS
   OUTFLOW: MODERATE EASTWARD

ANALYSIS CONFIDENCE:
   INITIAL POSITION: MEDIUM
   INITIAL INTENSITY: MEDIUM
   INITIAL WIND RADII: HIGH

3. FORECAST REASONING.

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

FORECAST DISCUSSION: TROPICAL STORM 19W (JEBI) IS ACCELERATING
NORTHEASTWARD INTO THE MID-LATITUDE WESTERLIES, AND IS NOW OVER
COOL WATERS NORTH OF THE KUROSHIO CURRENT. STEADY WEAKENING IS THUS
EXPECTED UNTIL THE STORM BECOMES EXTRATROPICAL IN ABOUT 24 HOURS.
HOWEVER, MAX WINDS MAY REMAIN AT OR ABOVE GALE FORCE BY THE TIME
EXTRATROPICAL TRANSITION OCCURS. DYNAMICAL MODELS ARE IN GOOD
AGREEMENT THAT JEBI WILL CONTINUE NORTHEASTWARD TO A POSITION JUST
SOUTHEAST OF THE KAMCHATKA PENINSULA IN 24 HOURS, BECOMING EMBEDDED
WITHIN THE EASTERN FLANK OF A BAROCLINIC LOW DEVELOPING WEST OF THE
KAMCHATKA PENINSULA AT THAT TIME.

MODEL DISCUSSION: THE JTWC TRACK FORECAST IS CLOSE TO THE
MULTI-MODEL CONSENSUS. THE JTWC INTENSITY FORECAST IS SLIGHTLY
ABOVE THE MULTI-MODEL CONSENSUS DUE TO THE STRENGTH OF THE
EXTRATROPICAL WIND FIELD EXPECTED BY GLOBAL MODELS.

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