WDPN31 PGTW 312100
MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI//
SUBJ/PROGNOSTIC REASONING FOR TROPICAL STORM 02W (MAWAR) WARNING NR 
048//
RMKS/
1. FOR METEOROLOGISTS.
2. 6 HOUR SUMMARY AND ANALYSIS.

SUMMARY:
   INITIAL POSITION: 23.5N 125.6E
   INITIAL INTENSITY: 60 KTS
   GEOGRAPHIC REFERENCE: 216 NM SOUTHWEST OF KADENA AB
   MOVEMENT PAST 6 HOURS: NORTHWARD AT 08 KTS
   SIGNIFICANT WAVE HEIGHT: 28 FEET

SATELLITE ANALYSIS, INITIAL POSITION AND INTENSITY DISCUSSION:
ANIMATED ENHANCED INFRARED (EIR) SATELLITE IMAGERY ALONG WITH
LOOPING RADAR IMAGERY DEPICT RAGGED BANDS OF CONVECTION WRAPPING
INTO AN ASSESSED LOW LEVEL CIRCULATION CENTER (LLCC). THE DEEPEST
CONVECTION CAN BE FOUND ON THE EASTERN SEMI-CIRCLE OF THE LLCC IN
BOTH THE INNER AND OUTER BANDS. A PARTIAL 311223Z ASCAT-C AND A
PARTIAL 311310Z ASCAT-B PASS SHOW AN EXPANSIVE 35 KNOT WIND FIELD
IN THE EASTERN SEMI-CIRCLE, WITH SEVERAL POCKETS OF ELEVATED WINDS
EAST OF THE LLCC. ANALYSIS OF THE 311800Z POSITION REVELS THE
SYSTEM HAS SLIGHTLY PICKED UP IN TRACK SPEED TO 08 KNOTS AND STILL
ON A NORTHWARD TRAJECTORY. TS MAWAR IS IN A MARGINALLY FAVORABLE
ENVIRONMENT FOR FURTHER TROPICAL ACTIVITY. THESE CONDITIONS ARE
CHARACTERIZED BY MODERATE RADIAL OUTFLOW ALOFT, A STRONG 850 MB
VORTICITY SIGNATURE, LOW (5-10 KTS) VERTICAL WIND SHEAR (VWS),
OFFSET BY COOL (26-27 C) SEA SURFACE TEMPERATURES (SST). THE
INITIAL POSITION IS PLACED WITH HIGH CONFIDENCE BASED ON
MULTI-AGENCY FIXES, ALONG WITH THE AFOREMENTIONED EIR AND RADAR
IMAGERY. THE INITIAL INTENSITY OF 60 KNOTS IS ASSESSED WITH MEDIUM
CONFIDENCE BASED OFF A BLEND OF MULTI-AGENCY AND AUTOMATED DVORAK
ESTIMATES, AND ALSO TAKING INTO ACCOUNT THE LLCC POSITIONING OVER
THE COOLER SSTS.

INITIAL WIND RADII BASIS: A PARTIAL 311223Z ASCAT-C AND A PARTIAL
311310Z ASCAT-B PASS

CURRENT STEERING MECHANISM: COMPETING STEERING PATTERN WITH A
DEEP-LAYER SUBTROPICAL RIDGE (STR) POSITIONED TO THE EAST AND
ANOTHER STR ENTRENCHED OVER SOUTHEAST CHINA. 

AGENCY DVORAK AND AUTOMATED FIXES: 
   PGTW: T4.0 - 65 KTS
   RJTD: T3.5 - 55 KTS
   KNES: T4.0 - 65 KTS
   CIMSS SATCON: 70 KTS AT 311641Z
   CIMSS ADT: 34 KTS AT 311930Z

FORECASTER ASSESSMENT OF CURRENT ENVIRONMENT: MARGINALLY FAVORABLE
   VWS: 5-10 KTS
   SST: 26-27 CELSIUS
   OUTFLOW: MODERATE RADIAL
   OTHER FACTORS: UPWELLING

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: TS 02W (MAWAR) CONTINUES TO RIDE THE WESTERN
PERIPHERY OF THE STR TO THE EAST. THIS STR IS ANTICIPATED TO
WEAKEN, HOWEVER, THE TIMING OF THIS WEAKENING HAS BEEN CHALLENGING
AS THE 311200Z UPPER LEVEL SOUNDING FROM MINAMIDAITOJIMA REVEALS
CONTINUAL SOUTHERLY FLOW UP TO APPROXIMATELY 400MB. THIS FLOW IS
PUSHING THE SYSTEM ON A NORTHWARD TRAJECTORY OVER THE PAST 12
HOURS. DUE TO THIS NORTHWARD TRACK, THE EVENTUAL TURN NORTHEASTWARD
IS NOW DELAYED THAN PREVIOUSLY FORECAST. AS A RESULT, THE FORECAST
TRACK IS NOW MORE POLEWARD PLACING IT OVER OKINAWA BETWEEN TAUS 18
AND 24. ALTHOUGH THE SYSTEM WILL BE TRANSITING OVER COOLER WATERS
AND ON AN OVERALL WEAKENING TREND DURING THIS TRAJECTORY, THE WINDS
NEAR THE CORE ARE FORECAST TO BE 50 KNOTS THROUGH TAU 36 AS THE
PRESSURE GRADIENT WILL REMAIN TIGHT DURING THIS TIME. BY TAU 48, TS
02W WILL BEGIN ITS EXTRATROPICAL TRANSITION AS AN APPROACHING UPPER
LEVEL TROUGH MAKES ITS WAY OVER HONSHU. BY TAU 72, THE SYSTEM WILL
BECOME FRONTAL AND COMPLETE ITS EXTRATROPICAL TRANSITION.

MODEL DISCUSSION: THE DETERMINISTIC AND ENSEMBLE MODELS ARE ALL IN
TIGHT AGREEMENT THAT TS MAWAR WILL TRACK NORTH-NORTHEASTWARD
THROUGH TAU 12, THEN MAKE THE TURN NORTHEASTWARD AFTERWARDS AS THE
STR TO THE NORTHWEST WILL BUILD IN AND TAKE OVER AS THE DOMINANT
STEERING MECHANISM. IN THE SHORT TERM, THE JTWC FORECAST TRACK
CONSENSUS MEMBERS ARE SHOWING A 29 NM SPREAD AT TAU 24 WITH A BULK
OF THE MEMBERS OVER OKINAWA DURING THIS TIME. THIS MODEL SPREAD
GRADUALLY INCREASES TO 92 NM BY THE END OF THE FORECAST PERIOD. DUE
TO THE UNCERTAIN TIMING OF THE STR TO THE EAST WEAKENING AND THE
STR TO THE NORTHWEST TAKING OVER AS THE PRIMARY STEERING MECHANISM,
THE JTWC FORECAST TRACK IS PLACED WITH MEDIUM CONFIDENCE THROUGHOUT
THE FORECAST PERIOD. THE JTWC INTENSITY CONSENSUS MEMBERS ALL AGREE
WITH A DECAYING TREND THROUGH TAU 72 AS THE SYSTEM TRANSITS INTO A
MORE HOSTILE ENVIRONMENT AND UNDERGOES EXTRATROPICAL TRANSITION.
CONSIDERING THE UNCERTAIN BEHAVIOR OVER THE NEXT SEVERAL TAUS, THE
JTWC INTENSITY FORECAST IS SET WITH MEDIUM CONFIDENCE.

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