000
WTPZ41 KNHC 161452
TCDEP1
TROPICAL STORM MARTY DISCUSSION NUMBER   2
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL   EP162009
800 AM PDT WED SEP 16 2009
 
EARLY MORNING VISIBLE SATELLITE IMAGERY SHOW THAT THE CENTER OF THE
CYCLONE IS LOCATED NEAR THE EASTERN EDGE OF THE DEEP CONVECTION.  A
1305 UTC QUIKSCAT PASS REVEALED SOME BELIEVABLE 35 KT WIND
VECTORS...AND THIS IS THE BASIS FOR UPGRADING THE DEPRESSION TO A
TROPICAL STORM...THE THIRTEENTH OF THE 2009 EASTERN NORTH PACIFIC
HURRICANE SEASON.
 
MARTY HAS ABOUT A 24-HOUR WINDOW OF OPPORTUNITY TO STRENGTHEN BEFORE
IT ENCOUNTERS INCREASING UPPER-LEVEL SOUTHWESTERLY WINDS.
THEREAFTER...THE CYCLONE WILL BE MOVING OVER SLOWLY DECREASING SSTS
WHICH SHOULD INDUCE A FASTER RATE OF DEMISE.  THE UPDATED INTENSITY
FORECAST IS SLIGHTLY HIGHER THAN THE PREVIOUS ADVISORY THROUGH 48
HOURS DUE TO THE INCREASE IN THE INITIAL INTENSITY.  HOWEVER...
MARTY IS STILL EXPECTED TO BECOME A REMNANT LOW IN AROUND 72 HOURS.
 
THE INITIAL MOTION ESTIMATE IS A HIGHLY UNCERTAIN 325/3.  THE TRACK
FORECAST SCENARIO REMAINS THE SAME AS THE PREVIOUS ADVISORY.  MARTY
IS CURRENTLY WITHIN AN AREA OF LIGHT STEERING FLOW....BUT A WEAK
RIDGE IS FORECAST TO BUILD OVER MEXICO DURING THE NEXT COUPLE OF
DAYS WHICH SHOULD CAUSE THE CYCLONE TO MOVE SLOWLY NORTH-
NORTHWESTWARD. THE OFFICIAL FORECAST IS CLOSE TO THE PREVIOUS NHC
TRACK AND THE MULTI-MODEL CONSENSUS. 
 
FORECAST POSITIONS AND MAX WINDS
 
INITIAL      16/1500Z 18.9N 112.4W    35 KT
 12HR VT     17/0000Z 19.3N 112.6W    40 KT
 24HR VT     17/1200Z 19.8N 112.8W    45 KT
 36HR VT     18/0000Z 20.6N 113.1W    40 KT
 48HR VT     18/1200Z 21.4N 113.3W    30 KT
 72HR VT     19/1200Z 23.0N 114.0W    25 KT...REMNANT LOW
 96HR VT     20/1200Z 24.0N 114.5W    20 KT...REMNANT LOW
120HR VT     21/1200Z...DISSIPATED
 
$$
FORECASTER BROWN