000
WTPZ45 KNHC 271435
TCDEP5
TROPICAL STORM DARBY DISCUSSION NUMBER  19
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL   EP052010
800 AM PDT SUN JUN 27 2010
 
STRONG EASTERLY SHEAR CONTINUES TO DISTORT THE CLOUD PATTERN OF
DARBY...WITH ALL OF ITS DEEP CONVECTION ON THE WESTERN SIDE OF THE
CIRCULATION.  SATELLITE CLASSIFICATIONS CONTINUE TO DROP...AND THE
INITIAL INTENSITY IS LOWERED TO 45 KT.  FURTHER WEAKENING WILL
LIKELY OCCUR AS A STRONG BURST OF UPPER-LEVEL EASTERLY WINDS
CURRENTLY SEEN ON WATER VAPOR IMAGES TO THE EAST OF DARBY IMPACTS
THE TROPICAL CYCLONE.  SINCE DARBY IS SUCH A SMALL TROPICAL CYCLONE
...IT WILL LIKELY NOT BE ABLE TO WITHSTAND SUCH HIGH SHEAR...AND IS
EXPECTED TO DECAY TO A REMNANT LOW WITHIN THE NEXT DAY OR TWO.  THE
NHC INTENSITY FORECAST REFLECTS THIS LIKELIHOOD AND IS NEAR...BUT A
LITTLE LOWER THAN...THE INTENSITY CONSENSUS.
 
AN AMSR-E MICROWAVE PASS AT 0854 UTC WAS EXTREMELY HELPFUL FOR
FINDING THE LOW-LEVEL CENTER...AND SUGGESTS THAT THE STORM HAS
BECOME NEARLY STATIONARY.  NOW THAT DARBY IS WEAKENING...IT IS
MORE LIKELY THAT THE STORM WILL EVENTUALLY BE STEERED NORTHEASTWARD
AS IT IS SWEPT UP BY A LARGE AREA OF SOUTHWESTERLY WINDS SOUTH OF
MEXICO.  THE MODEL GUIDANCE IS IN MUCH BETTER AGREEMENT ON THIS
SCENARIO...AND THE NHC FORECAST HAS BEEN ADJUSTED NORTHEASTWARD
FROM THE PREVIOUS ONE.  IT IS WORTH REPEATING THAT WHATEVER REMAINS
OF DARBY IN A COUPLE OF DAYS SHOULD BE QUITE WEAK AS IT APPROACHES
THE SOUTH COAST OF MEXICO.
 
FORECAST POSITIONS AND MAX WINDS
 
INITIAL      27/1500Z 13.7N 103.0W    45 KT
 12HR VT     28/0000Z 13.8N 102.8W    35 KT
 24HR VT     28/1200Z 14.2N 102.0W    30 KT
 36HR VT     29/0000Z 14.6N 100.7W    25 KT...POST-TROP/REMNT LOW
 48HR VT     29/1200Z 15.0N  99.4W    20 KT...POST-TROP/REMNT LOW
 72HR VT     30/1200Z...DISSIPATED
 
$$
FORECASTER BLAKE