349 
 WTNT43 KNHC 272032
 TCDAT3
 TROPICAL STORM LISA DISCUSSION NUMBER  34
 NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
 5 PM EDT MON SEP 27 2004
 
 LATEST SATELLITE IMAGERY CONTINUES TO DEPICT A SHEARED SYSTEM...WITH
 THE LOW-LEVEL CENTER EXPOSED TO THE SOUTHWEST OF THE MAIN AREA OF
 DEEP CONVECTION.  THERE IS NO REASON TO EXPECT THIS SHEAR TO RELAX
 SOON...SO THE INTENSITY FORECAST SHOWS LITTLE CHANGE IN STRENGTH
 FOR THE NEXT 1-2 DAYS.  LATER IN THE FORECAST PERIOD...AN
 UPPER-LEVEL LOW TO THE WEST OF LISA IS FORECAST TO BREAK UP AND
 THIS MAY ALLOW FOR A MORE FAVORABLE UPPER-LEVEL ENVIRONMENT.  THE
 CURRENT NHC WIND SPEED FORECAST SHOWS A LITTLE LESS STRENGTHENING
 THAN THE PREVIOUS ONES AND IS IN REASONABLE AGREEMENT WITH THE
 LATEST SHIPS GUIDANCE.  THE CURRENT GFDL RUN SHOWS MORE
 STRENGTHENING...BUT THAT MODEL HAS BEEN EXHIBITING A POSITIVE BIAS
 FOR THIS STORM THUS FAR.
 
 LATEST FIXES SHOW A SLIGHTLY FASTER MOTION TO THE NNW...340/7.  LISA
 IS BEING STEERED BY THE FLOW ON THE SOUTHWESTERN SIDE OF A MID-LEVEL
 SUBTROPICAL ANTICYCLONE.  TRACK GUIDANCE NOW SUGGESTS MORE OF A
 NORTHEASTWARD TURN LATER IN THE PERIOD DUE TO A WEAK APPROACHING
 SHORTWAVE IN THE WESTERLIES.  WE HAVE NOT ENTIRELY BOUGHT INTO THIS
 CHANGE...BUT HAVE SHIFTED THE TRACK SOMEWHAT TO THE EAST...TO BE AT
 LEAST PARTIALLY CONSISTENT WITH THE NEW GUIDANCE.  IT SHOULD BE
 NOTED THAT THE DYNAMICAL MODEL CONSENSUS IS EVEN FARTHER TO THE
 NORTHEAST OF THE OFFICIAL FORECAST.
 
 FORECASTER PASCH/SISKO
  
 FORECAST POSITIONS AND MAX WINDS
  
 INITIAL      27/2100Z 21.5N  46.5W    35 KT
  12HR VT     28/0600Z 22.5N  47.1W    35 KT
  24HR VT     28/1800Z 24.0N  47.9W    35 KT
  36HR VT     29/0600Z 25.5N  48.3W    35 KT
  48HR VT     29/1800Z 27.0N  48.5W    40 KT
  72HR VT     30/1800Z 30.5N  49.0W    50 KT
  96HR VT     01/1800Z 33.0N  49.0W    60 KT
 120HR VT     02/1800Z 35.0N  48.0W    60 KT
  
 $$