WDPN31 PGTW 011500
MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI//
SUBJ/PROGNOSTIC REASONING FOR TROPICAL STORM 02W (MAWAR) 
WARNING NR 051//
RMKS/
1. FOR METEOROLOGISTS.
2. 6 HOUR SUMMARY AND ANALYSIS.

SUMMARY:
   INITIAL POSITION: 25.8N 127.1E
   INITIAL INTENSITY: 50 KTS
   GEOGRAPHIC REFERENCE: 56 NM SOUTHWEST OF KADENA AB
   MOVEMENT PAST 6 HOURS: NORTHEASTWARD AT 11 KTS
   SIGNIFICANT WAVE HEIGHT: 25 FEET

SATELLITE ANALYSIS, INITIAL POSITION AND INTENSITY DISCUSSION:
ANIMATED ENHANCED INFRARED (EIR) SATELLITE IMAGERY DEPICTS A
TIGHTLY-WRAPPED CIRCULATION. CONVERGENT FLOW ASSOCIATED WITH AN
UPPER-LEVEL SHORTWAVE TROUGH IS SUPPRESSING CONVECTION ON THE
WESTERN SIDE OF THE CIRCULATION, WHILE CONVERGENT LOW-LEVEL INFLOW 
AND DIVERGENT UPPER-LEVEL OUTFLOW CONTINUE TO SUPPORT CONVECTIVE
DEVELOPMENT TO THE EAST AND SOUTH OF THE SYSTEM CENTER. THE INITIAL
POSITION IS PLACED WITH HIGH CONFIDENCE BASED ON A PARTIALLY-EXPOSED 
CENTER FEATURE EVIDENT IN 011200Z INFRARED IMAGERY AND RECENT RADAR 
DATA. THE INITIAL INTENSITY OF 50 KTS IS ASSESSED WITH HIGH CONFIDENCE 
BASED ON WIND AND PRESSURE OBSERVATIONS FROM THE ISLAND OF OKINAWA.

INITIAL WIND RADII BASIS: OBJECTIVE BEST TRACK AND SYNOPTIC
OBSERVATIONS

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

AGENCY DVORAK AND AUTOMATED FIXES: 
   PGTW: T2.5 - 35 KTS
   RJTD: T3.0 - 45 KTS
   KNES: T3.0 - 45 KTS
   CIMSS ADT: 32 KTS AT 010830Z

FORECASTER ASSESSMENT OF CURRENT ENVIRONMENT: MARGINALLY
UNFAVORABLE
   VWS: 10-15 KTS
   SST: 26-27 CELSIUS
   OUTFLOW: MODERATE POLEWARD AND EQUATORWARD

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

3. FORECAST REASONING.

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

FORECAST DISCUSSION: TS 02W IS TURNING EASTWARD AROUND THE
NORTHWESTERN PERIPHERY OF THE STEERING RIDGE AND WILL CONTINUE ON A
GENERALLY NORTHEASTWARD TRAJECTORY THROUGHOUT THE FORECAST PERIOD. 
THE SYSTEM WILL REMAIN SOUTH OF THE FAIRLY ZONAL MIDLATITUDE
WESTERLY FLOW PATTERN OVER THE NEXT DAY AND A HALF BEFORE FINALLY
MERGING WITH A DEVELOPING MIDLATITUDE TROUGH AND TRANSITIONING TO
AN EXTRATROPICAL LOW BETWEEN TAU 36 AND 72. THE SYSTEM IS EXPECTED
TO WEAKEN ONLY SLIGHTLY THROUGHOUT THE FORECAST PERIOD DUE TO
SUPPORTIVE EASTWARD AND POLEWARD UPPER-LEVEL FLOW IN THE NEAR-TERM, 
AND BY FAVORABLE BAROCLINIC INTERACTION WITH THE APPROACHING 
MIDLATITUDE TROUGH LATER IN THE FORECAST PERIOD. 

MODEL DISCUSSION: CONSENSUS MODEL TRACK FORECAST GUIDANCE REMAINS
IN GOOD AGREEMENT REGARDING THE OVERALL SCENARIO. ALONG-TRACK
SPREAD INCREASES AT THE TAU 36 MARK AS THE GFS-BASED MODELS AND
NAVGEM MODEL INDICATE A TIGHTER EASTWARD TURN AND A LONGER PERIOD
PRECEDING MERGER INTO THE MIDLATITUDE BAROCLINIC ZONE. THE
REMAINDER OF THE CONSENSUS MODEL GUIDANCE BRACKETS THE NORTHERN
SIDE OF THE ENVELOPE, DEPICTING A SMOOTHER AND FASTER TRACK INTO
THE WESTERLIES. CROSS-TRACK SPREAD IS LOW THROUGHOUT THE LATER
PORTION OF THE FORECAST, PROVIDING HIGH CERTAINTY THAT THE SYSTEM
WILL REMAIN WELL TO THE SOUTH AND EAST OF HONSHU AS IT UNDERGOES
EXTRATROPICAL TRANSITION. DYNAMIC MODEL INTENSITY FORECAST GUIDANCE
IS IN GOOD AGREEMENT WITH THE MUTED WEAKENING TREND REFLECTED IN
THE CURRENT FORECAST, WHICH IS SET WITH HIGH CONFIDENCE.

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