000
WTPZ44 KNHC 302036
TCDEP4
TROPICAL STORM KEVIN DISCUSSION NUMBER   6
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL   EP142009
200 PM PDT SUN AUG 30 2009
 
VISIBLE AND ENHANCED BD-CURVE IMAGERY INDICATE THAT KEVIN HAS BEGUN
TO WEAKEN DUE TO PERSISTENT EASTERLY SHEAR AND A LESS THAN
FAVORABLE THERMODYNAMIC ENVIRONMENT. A 1346 UTC QUIKSCAT
AMBIGUITY ANALYSIS REVEALED A SMALL PATCH OF REASONABLE 40 KT WINDS
JUST TO THE WEST OF THE SURFACE CIRCULATION.  SATELLITE INTENSITY
DATA-T NUMBERS ARE 35 AND 45 KT FROM TAFB AND SAB...RESPECTIVELY.
THE INITIAL INTENSITY IS LOWERED TO 40 KT BASED ON THE QUIKSCAT
OVERPASS AND A COMPROMISE OF THE DVORAK ESTIMATES. KEVIN SHOULD
CONTINUE TO SLOWLY SPIN DOWN AND BECOME A REMNANT LOW AROUND DAY 4
AS THE CYCLONE GRADUALLY MOVES IN A GENERAL NORTHEASTWARD MOTION
TOWARD AN EVEN LESS FAVORABLE ENVIRONMENT.  THE OFFICIAL INTENSITY
FORECAST REFLECTS THIS SCENARIO AND COINCIDES WITH THE SHIPS AND
HURRICANE MODELS.
 
KEVIN IS MAINTAINING A SLOW NORTHWARD MOTION THIS AFTERNOON...360/5.
THE STEERING FLOW IS PRODUCED BY A MID-TROPOSPHERIC ANTICYCLONE TO
THE SOUTHEAST AND A MID TO UPPER-LEVEL TROUGH EXTENDING SOUTHWEST
FROM SOUTHERN BAJA CALIFORNIA. THIS WEAKNESS IN THE SUBTROPICAL
RIDGE IS EXPECTED TO BECOME MORE PRONOUNCED BY MID PERIOD IN
RESPONSE TO HURRICANE JIMENA MOVING INTO THE REGION. THIS SHOULD
CAUSE KEVIN TO DRIFT NORTHEASTWARD BEYOND THE 48 HOUR PERIOD. THE
OFFICIAL FORECAST IS CLOSE TO THE PREVIOUS TRACK AND IS AGAIN BASED
ON THE TVCN MODEL CONSENSUS.

FORECAST POSITIONS AND MAX WINDS
 
INITIAL      30/2100Z 15.3N 121.9W    40 KT
 12HR VT     31/0600Z 15.8N 121.4W    35 KT
 24HR VT     31/1800Z 16.6N 120.7W    35 KT
 36HR VT     01/0600Z 17.3N 120.0W    30 KT
 48HR VT     01/1800Z 17.9N 119.4W    30 KT
 72HR VT     02/1800Z 18.9N 118.7W    25 KT
 96HR VT     03/1800Z 19.3N 118.5W    25 KT...REMNANT LOW
120HR VT     04/1800Z 19.6N 118.5W    25 KT...REMNANT LOW
 
$$
FORECASTER ROBERTS/PASCH