747 
 WTNT43 KNHC 221455
 TCDAT3
 TROPICAL STORM LISA DISCUSSION NUMBER  13
 NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
 11 AM EDT WED SEP 22 2004
  
 VISIBLE IMAGERY THIS MORNING SHOWS A SMALL...MOSTLY EXPOSED
 CIRCULATION TO THE NORTH OR NORTHEAST OF THE CORE CONVECTION.  THE
 INITIAL INTENSITY IS LOWERED BASED ON THE MOST RECENT QUIKSCAT PASS 
 AND DVORAK CLASSIFICATIONS.  LISA IS BEING AFFECTED BY THE LARGER
 AREA OF DISTURBED WEATHER TO ITS EAST-SOUTHEAST...AS THE INITIAL
 MOTION IS NOW 250/5.  IT ALSO IS SUFFERING FROM EASTERLY SHEAR FROM
 THE SOUTH SIDE OF AN UPPER-LEVEL RIDGE BETWEEN LISA AND KARL.  ALL
 IN ALL...THIS IS NOT A SCENARIO THAT WOULD FAVOR INTENSIFICATION IN
 THE SHORT TERM...AND IN FACT...LISA COULD GET ABSORBED BY THE
 EASTERN DISTURBANCE OVER THE NEXT COUPLE OF DAYS.  THE OFFICIAL
 FORECAST WILL CALL FOR LITTLE CHANGE IN STRENGTH FOR 72
 HOURS...FOLLOWED BY SLOW STRENGTHENING AS INDICATED BY BOTH THE
 SHIPS AND GFDL MODELS.  HOWEVER...IT SHOULD BE NOTED THAT BOTH THE
 GFS AND UKMET DROP AN UPPER TROUGH DEEP INTO THE CENTRAL ATLANTIC
 BY DAY FIVE...AND THIS WOULD TEND TO PROVIDE AN UNFAVORABLE
 ENVIRONMENT FOR EITHER LISA OR THE DISTURBANCE BEHIND IT.
 
 NUMERICAL MODELS CONTINUE TO SHOW A WIDE RANGE OF POSSIBLE TRACKS
 FOR LISA.  HOWEVER...THE INTERACTION PREDICTED FOR THE PAST TWO
 DAYS BY THE GFDL IS NOW BEGINNING...AND SO CONSIDERABLE WEIGHT HAS
 BEEN PLACED ON THIS MODEL.  LISA IS EXPECTED TO SLOW AND TURN MORE
 SOUTHWARD AROUND THE EASTERN DISTURBANCE.  IF LISA SURVIVES...IN
 THIS SCENARIO IT WOULD THEN TURN NORTHWESTWARD AROUND THE BACK SIDE
 OF THE DISTURBANCE.  SUCH A SCENARIO BECOMES MORE LIKELY IF LISA'S
 CIRCULATION REMAINS MOSTLY EXPOSED...WHILE A STRONGER CYCLONE WOULD
 BE MORE LIKELY TO CONTINUE A SIMPLER WESTWARD TRACK IN RESPONSE TO
 THE UPPER-LEVEL EASTERLIES.  
 
 FORECASTER FRANKLIN
  
 FORECAST POSITIONS AND MAX WINDS
  
 INITIAL      22/1500Z 13.9N  41.3W    45 KT
  12HR VT     23/0000Z 13.8N  41.7W    45 KT
  24HR VT     23/1200Z 13.2N  42.3W    45 KT
  36HR VT     24/0000Z 13.0N  42.5W    45 KT
  48HR VT     24/1200Z 13.0N  43.0W    45 KT
  72HR VT     25/1200Z 14.0N  44.5W    50 KT
  96HR VT     26/1200Z 16.0N  45.5W    60 KT
 120HR VT     27/1200Z 20.0N  48.0W    70 KT
  
  
 $$