WDPN33 PGTW 040300
MSGID/GENADMIN/NAVMARFCSTCEN PEARL HARBOR HI/JTWC//
SUBJ/PROGNOSTIC REASONING FOR TROPICAL STORM 10W WARNING NR 10//
RMKS/
1. FOR METEOROLOGISTS.
2. 12 HOUR SUMMARY AND ANALYSIS.
   A. TROPICAL STORM (TS) 10W (MALOU), LOCATED APPROXIMATELY 135 NM
SOUTH-SOUTHWEST OF KADENA AB, OKINAWA, JAPAN, HAS TRACKED WESTWARD
AT 06 KNOTS OVER THE PAST SIX HOURS. ANIMATED MULTISPECTRAL SATELLITE
IMAGERY (MSI) AND A 032330Z SSMIS 91 GHZ MICROWAVE IMAGE SHOW DEEP CONVECTION
ALONG THE SOUTHERN HALF OF A WELL DEFINED LOW LEVEL CIRCULATION CENTER (LLCC) WITH
ADDITIONAL DEEP CONVECTION, POSSIBLY ASSOCIATED WITH A TROPICAL DISTURBANCE,
150 NM EAST OF TS 10W. THE CURRENT POSITION IS BASED, WITH FAIR CONFIDENCE,
ON ANIMATED MSI AND THE AFOREMENTIONED SSMIS MICROWAVE PASS. THE CURRENT
INTENSITY IS BASED ON DVORAK ESTIMATES RANGING FROM 30 TO 35 FROM PGTW, KNES,
AND  RJTD. THIS INTENSITY IS VERIFIED BY OBSERVATIONS NORTH OF THE
DEEP CONVECTION INDICATING 20 TO 30 KNOTS AND BAROMETER MEASUREMENTS OF 997
MB  AND 999 MB. AN UPPER LEVEL LOW, PREVIOUSLY
IMPINGING OUTFLOW ALONG THE WESTERN FLANK OF TS 10W, HAS MOVED OFF TO THE
SOUTHWEST ALLOWING THE DIFFLUENT REGION OF THE LOW TO ENHANCE OUTFLOW OVER
THE SYSTEM. THE RECENT STORM MOTION IS SLOWER AND MORE WESTWARD THEN THE
PREVIOUS TRACK WHICH MAY BE AN INDICATION OF DIRECT CYCLONE INTERACTION
(DCI) WITH THE PREVIOUSLY MENTIONED TROPICAL DISTURBANCE EAST OF OKINAWA.
3. FORECAST REASONING.
   A. THE INITIAL PORTION OF THE FORECAST IS SLOWER AND MORE WESTWARD
THAN THE PREVIOUS FORECAST, HOWEVER THE FUNDAMENTAL PHILOSOPHY OF THE
TRACK AND INTENSITY FORECASTS REMAINS THE SAME.
   B. TS 10W IS CURRENTLY TRACKING UNDER THE INFLUENCE OF A LOW TO MID-LEVEL
SUBTROPICAL RIDGE (STR) ORIENTATED SOUTH OF MAINLAND JAPAN, HOWEVER
INTERACTION WITH A DEVELOPING TROPICAL DISTURBANCE EAST OF TS 10W HAS
SLOWED ITS OVERALL SPEED OF ADVANCE. THE SYSTEM IS EXPECTED TO GRADUALLY
INTENSIFY AND CONTINUE TRACKING POLEWARD AS THE WESTERN EXTENT OF THE
STR BREAKS DOWN IN RESPONSE TO A PASSING MID-LATITUDE TROUGH. HOWEVER, THERE
IS SOME UNCERTAINTY IN THE TRACK DUE TO POSSIBLE DCI WITH THE DEVELOPING
TROPICAL DISTURBANCE TO THE EAST.
   C. AFTER TAU 72, TS MALOU IS EXPECTED TO CONTINUE TRACKING POLEWARD TO
NORTHEASTWARD AND WEAKEN AS IT INTERACTS WITH THE MID-LATITUDE WESTERLIES
AND TRACKS OVER COOLER SEA SURFACE TEMPERATURES IN THE NORTHERN YELLOW
SEA. NUMERICAL MODEL GUIDANCE IS IN POOR AGREEMENT AFTER TAU 24, IN RESPONSE
TO A WEAK STEERING ENVIRONMENT AND POOR HANDLING OF THE INTERACTION WITH
THE DEVELOPING TROPICAL DISTURBANCE EAST OF THE SYSTEM. GFS, EGRR, AND JGSM
TRACK THE SYSTEM WEST TO NORTHWESTWARD INTO EASTERN CHINA, WHILE NOGAPS,
WBAR, AND ECMWF SHOW A MORE POLEWARD TO NORTHEASTWARD TRACK. THIS FORECAST
IS SLOWER THAN MODEL CONSENSUS TO ACCOUNT FOR THESE UNCERTAINTIES.//
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