WDPN31 PGTW 010300
MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI//
SUBJ/PROGNOSTIC REASONING FOR TROPICAL STORM 02W (MAWAR) WARNING NR 
049//
RMKS/
1. FOR METEOROLOGISTS.
2. 6 HOUR SUMMARY AND ANALYSIS.

SUMMARY:
   INITIAL POSITION: 24.2N 125.9E
   INITIAL INTENSITY: 55 KTS
   GEOGRAPHIC REFERENCE: 172 NM SOUTHWEST OF KADENA AB
   MOVEMENT PAST 6 HOURS: NORTH-NORTHEASTWARD AT 08 KTS
   SIGNIFICANT WAVE HEIGHT: 26 FEET

SATELLITE ANALYSIS, INITIAL POSITION AND INTENSITY DISCUSSION:
ANIMATED MULTISPECTRAL SATELLITE IMAGERY (MSI) ALONG WITH LOOPING
RADAR IMAGERY DEPICT FRAGMENTED BANDS OF CONVECTION WRAPPING INTO
AN ASSESSED LOW LEVEL CIRCULATION CENTER (LLCC). THE DEEPEST
CONVECTION IS LOCATED TO THE EAST OF THE LLCC IN THE INNER BANDS,
AND IN THE NORTHEASTERN QUADRANT IN THE OUTER BANDS. RECENT SURFACE
OBSERVATIONS FROM KADENA AIR BASE (RODN) INDICATE EASTERLY WINDS
WITH GUSTS IN THE 35-40 KNOT RANGE WITH A FEW PEAK WIND RECORDINGS
OF 41 KNOTS. ANALYSIS OF THE 312100Z JTWC THREE HOURLY UPDATED
POSITION (JTUP) AND THE 010000Z BEST TRACK POSITION REVEALS THE
SYSTEM HAS BEGUN ITS NORTH-NORTHEASTWARD TRAJECTORY AS THE STR TO
THE EAST BEGINS TO WANE ITS INFLUENCE ON THE SYSTEM AND THE STR TO
THE NORTHWEST BECOMES THE DOMINANT STEERING MECHANISM. 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 MSI AND RADAR IMAGERY. THE INITIAL INTENSITY OF 55
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: PERSISTENCE

CURRENT STEERING MECHANISM: A SUBTROPICAL RIDGE (STR) TO THE
NORTHWEST AND A STR TO THE EAST

AGENCY DVORAK AND AUTOMATED FIXES: 
   PGTW: T3.0 - 45 KTS
   RJTD: T3.0 - 45 KTS
   KNES: T4.0 - 65 KTS
   CIMSS SATCON: 62 KTS AT 311730Z
   CIMSS ADT: 33 KTS AT 312330Z

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. THROUGH TAU 12, THE SYSTEM WILL
TURN EVEN MORE NORTHEASTWARD TOWARDS OKINAWA AS THE STR FROM THE
NORTHWEST CONTINUES TO BUILD IN THE AREA. 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 24 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 CONTINUES TO BUILD IN. IN THE SHORT TERM, THE
JTWC FORECAST TRACK CONSENSUS MEMBERS ARE SHOWING A 28 NM SPREAD AT
TAU 24 WITH A BULK OF THE MEMBERS OVER OKINAWA DURING THIS TIME.
THIS MODEL SPREAD GRADUALLY INCREASES BY THE END OF THE FORECAST
PERIOD. AS A RESULT, THE JTWC FORECAST TRACK IS PLACED WITH HIGH
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. THE JTWC INTENSITY FORECAST IS SET WITH
MEDIUM CONFIDENCE THROUGHOUT THE FORECAST PERIOD.

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