000
WTPZ42 KNHC 240831
TCDEP2
TROPICAL STORM ANDRES DISCUSSION NUMBER  11
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL   EP022009
200 AM PDT WED JUN 24 2009

SATELLITE IMAGES SHOW A DETERIORATING CLOUD PATTERN ASSOCIATED WITH
THE STORM...AS A RAGGED-LOOKING MASS OF DEEP CONVECTION IS BEING
SHEARED SOUTHWESTWARD AWAY FROM THE ESTIMATED LOW-LEVEL CENTER.  IT
APPEARS THAT ANDRES IS SUCCUMBING TO THE PERSISTENT EAST-
NORTHEASTERLY SHEAR THAT HAS BEEN IMPACTING IT OVER THE PAST DAY OR
TWO.  THE CURRENT INTENSITY IS SET AT 50 KT BASED ON A BLEND OF
DVORAK ESTIMATES FROM TAFB AND SAB...ALTHOUGH THIS MIGHT BE A
GENEROUS ESTIMATE.  OVER THE NEXT COUPLE OF DAYS...THE OCEANIC AND
ATMOSPHERIC ENVIRONMENT OF ANDRES SHOULD BECOME INCREASINGLY LESS
CONDUCIVE FOR THE MAINTENANCE OF A TROPICAL CYCLONE.  THE SYSTEM IS
LIKELY TO WEAKEN TO A TROPICAL DEPRESSION IN 36 HOURS OR LESS.  THE
OFFICIAL INTENSITY FORECAST IS IN GOOD AGREEMENT WITH THE LATEST
SHIPS GUIDANCE.

INITIAL MOTION IS ESTIMATED TO BE AROUND 305/8 ALTHOUGH THE CENTER
POSITION IS RATHER IMPRECISE AT THE MOMENT.  THE PRIMARY STEERING
MECHANISM AT THIS TIME IS A MID-LEVEL RIDGE TO THE NORTH OF THE
TROPICAL CYCLONE.  SOME SLOWING OF THE FORWARD SPEED IS LIKELY OVER
THE NEXT DAY OR SO AS THE MOTION OF THE WEAKENING CYCLONE BECOMES
DOMINATED BY THE LOWER-TROPOSPHERIC WINDS...WHICH ARE SOMEWHAT
WEAKER THEN THE WINDS AT THE MIDDLE LEVELS.  THE OFFICIAL TRACK
FORECAST IS ESSENTIALLY AN UPDATE OF THAT FROM THE PREVIOUS
ADVISORY PACKAGE...AND IS NEAR THE SOUTH SIDE OF THE TRACK MODEL
GUIDANCE SUITE.
 
FORECAST POSITIONS AND MAX WINDS
 
INITIAL      24/0900Z 19.5N 106.7W    50 KT
 12HR VT     24/1800Z 20.3N 107.7W    45 KT
 24HR VT     25/0600Z 21.2N 109.1W    35 KT
 36HR VT     25/1800Z 21.8N 110.6W    30 KT
 48HR VT     26/0600Z 22.3N 112.0W    25 KT...REMNANT LOW
 72HR VT     27/0600Z 23.0N 115.0W    20 KT...REMNANT LOW
 96HR VT     28/0600Z...DISSIPATED
 
$$
FORECASTER PASCH