Tropical Storm ANDRES

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TROPICAL STORM ANDRES DISCUSSION NUMBER  13
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
8 PM PDT THU MAY 22 2003

ANDRES CONTINUES TO BE SHEARED FROM THE WEST AND NORTHWEST.
HOWEVER...RECENTLY A FAIRLY IMPRESSIVE BURST OF DEEP CONVECTION
OCCURRED NEAR THE CENTER. DVORAK T-NUMBERS HAVE DROPPED BELOW
TROPICAL STORM STRENGTH BUT BECAUSE OF THE CONVECTIVE BURST...THE
FAST FORWARD MOTION...AND THE UNCERTAINTY IN SATELLITE-BASED
INTENSITY ESTIMATES...THE WINDS ARE MAINTAINED AT 35 KT FOR THIS
ADVISORY.  HOPEFULLY WE WILL GET A QUIKSCAT PASS OVER THE SYSTEM IN
A FEW HOURS...AND OBTAIN A BETTER ESTIMATE OF THE INTENSITY.
ALTHOUGH THE CYCLONE SHOULD REMAIN OVER RELATIVELY WARM WATER FOR
ANOTHER DAY OR SO...THE SHEARING ALONG WITH SUBSIDENCE ASSOCIATED
WITH AN UPPER-LEVEL RIDGE JUST TO THE WEST OF ANDRES SHOULD CAUSE
WEAKENING.

ANDRES IS EMBEDDED IN A SWIFT TRADEWIND FLOW AND CONTINUES TO
MOVE RAPIDLY WESTWARD...280/19.  IN FACT A SIGNIFICANT PART OF THE
VERTICAL SHEAR ON THE SYSTEM MAY BE DUE TO THE STRONG LOW-LEVEL
EASTERLIES.  THERE IS LITTLE CHANGE TO THE TRACK FORECAST REASONING
FROM THE PREVIOUS ADVISORY.  A WESTWARD TO WEST-NORTHWESTWARD
MOTION IS PREDICTED...WITH A GRADUAL DECREASE IN FORWARD SPEED AS
THE MID-LEVEL RIDGE TO THE NORTH OF ANDRES IS EXPECTED TO WEAKEN
SOMEWHAT.  LATER IN THE PERIOD...A DUE WESTWARD TRACK IS EXPECTED
AS THE STEERING IS LIKELY TO BE DOMINATED BY THE LOW-LEVEL WINDS. 
THIS OFFICIAL FORECAST IS VERY SIMILAR TO THE TRACK SHOWN BY THE
LATEST GFDL MODEL RUN.

FORECASTER PASCH
 
FORECAST POSITIONS AND MAX WINDS
 
INITIAL      23/0300Z 12.0N 121.6W    35 KT
 12HR VT     23/1200Z 12.5N 124.0W    35 KT
 24HR VT     24/0000Z 13.1N 127.0W    30 KT
 36HR VT     24/1200Z 13.6N 129.7W    30 KT
 48HR VT     25/0000Z 14.0N 132.0W    25 KT
 72HR VT     26/0000Z 14.5N 136.5W    25 KT
 96HR VT     27/0000Z 14.5N 140.0W    20 KT...REMNANT LOW
120HR VT     28/0000Z 14.5N 143.5W    20 KT...REMNANT LOW
 
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