000
WTPZ45 KNHC 150234
TCDEP5
TROPICAL STORM ISELLE DISCUSSION NUMBER   7
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL   EP102008
800 PM PDT THU AUG 14 2008
 
THERE HAS BEEN VERY LITTLE CHANGE IN ISELLE'S CLOUD PATTERN THIS
EVENING.  ENHANCED INFRARED IMAGERY AND AN AMSR-E MICROWAVE OVERPASS
DEPICT THAT THE SURFACE CIRCULATION IS BENEATH THE NORTHEASTERN
EDGE OF THE DEEP CONVECTION...DUE TO THE PERSISTENT 20 TO 30 KT OF
EASTERLY SHEAR.  ALL OF THE AVAILABLE INTENSITY MODELS SUGGEST THAT
THE AFOREMENTIONED SHEAR ENVIRONMENT WILL CONTINUE TO AFFECT THE
CYCLONE THROUGH THE FORECAST PERIOD IN ADDITION TO GRADUALLY
DECREASING SEA-SURFACE TEMPERATURES.  THIS SCENARIO IS REFLECTED IN
THE OFFICIAL INTENSITY FORECAST WHICH CALLS FOR ISELLE TO BECOME A
REMNANT LOW IN 2 DAYS.    
 
INITIAL MOTION IS ESTIMATED AT 270/8...A LITTLE TO THE LEFT OF THE
PREVIOUS ADVISORY.  WITH THE EXCEPTION OF NOGAPS...THE GLOBAL
MODELS CONTINUE TO REVEAL A NORTHWEST TRACK BIAS...POSSIBLY DUE TO
SOME BINARY INTERACTION WITH THE RATHER LARGE AREA OF LOW PRESSURE
A FEW HUNDRED MILES TO THE WEST-SOUTHWEST OF ISELLE. 
CONSEQUENTLY...THE NHC TRACK FORECAST IS PLACED TO THE LEFT OF THE
MODEL CONSENSUS AND IS NUDGED TOWARD THE NOGAPS WHICH APPEARS TO BE
ACCURATELY DEPICTING THE LOW TO MID LAYER STEERING FLOW PRODUCED BY
A RIDGE EXTENDING WESTWARD FROM CENTRAL MEXICO.
 
FORECAST POSITIONS AND MAX WINDS
 
INITIAL      15/0300Z 17.7N 111.1W    40 KT
 12HR VT     15/1200Z 18.0N 112.0W    40 KT
 24HR VT     16/0000Z 18.4N 113.2W    35 KT
 36HR VT     16/1200Z 18.8N 114.3W    30 KT
 48HR VT     17/0000Z 19.1N 115.2W    25 KT...REMNANT LOW
 72HR VT     18/0000Z 19.4N 116.5W    25 KT...REMNANT LOW
 96HR VT     19/0000Z 19.5N 118.0W    20 KT...REMNANT LOW
120HR VT     20/0000Z 19.5N 119.5W    20 KT...REMNANT LOW
 
$$
FORECASTER ROBERTS/AVILA