203 
 WTNT44 KNHC 260234
 TCDAT4
 TROPICAL STORM LISA DISCUSSION NUMBER  22
 NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL   AL142010
 1100 PM AST SAT SEP 25 2010
  
 MICROWAVE IMAGES FROM THIS EVENING INDICATE THAT LISA HAS BEEN
 MOVING MORE TOWARD THE NORTH-NORTHWEST...WITH THE CENTER BECOMING
 EXPOSED TO THE SOUTHWEST OF VERY LIMITED DEEP CONVECTION. DVORAK
 CLASSIFICATIONS ARE DECREASING AS FAST AS THE RULES ALLOW...AND THE
 INITIAL WIND SPEED IS LOWERED TO 40 KT. COOL WATERS...DRY AIR...AND
 STRONG SOUTHWESTERLY SHEAR SHOULD FINISH OFF LISA BY MONDAY UNLESS
 THE CYCLONE PULLS ANOTHER SURPRISE. THE GUIDANCE IS IN GOOD
 AGREEMENT ON THE WEAKENING SCENARIO...AND THE OFFICIAL FORECAST IS
 BASICALLY AN UPDATE OF THE PREVIOUS ONE.
  
 BASED ON SSMI/S IMAGES FROM EARLIER THE LOW-LEVEL CENTER HAS BEEN
 RELOCATED FARTHER WEST...AND IS MOVING AT ABOUT 340/8. A NORTH-
 NORTHWESTWARD MOTION IS EXPECTED UNTIL DISSIPATION IN A DAY OR TWO
 AS THE CYCLONE MOVES BETWEEN A TROUGH OVER THE EASTERN ATLANTIC
 OCEAN AND RIDGE NEAR NORTHWESTERN AFRICA. SOME MODEL GUIDANCE...
 SUCH AS THE HWRF/GFDL...SHOW THE CYCLONE TAKING A TRACK TOWARD THE
 NORTH OR NORTH-NORTHEAST...BUT THESE MODELS ALSO HAVE A MUCH MORE
 VERTICALLY COHERENT CYCLONE. SINCE THIS STRUCTURE IS UNLIKELY TO
 OCCUR...THE NHC FORECAST WILL REMAIN ON THE LEFT SIDE OF THE
 GUIDANCE. THE NEW FORECAST HAS BEEN SHIFTED TO THE WEST...BUT THAT
 IS MOSTLY DUE TO THE CENTER RELOCATION. THE REMNANT LOW SHOULD MOVE
 VERY SLOWLY BY THE END OF THE PERIOD AS SURFACE HIGH PRESSURE
 BUILDS NEAR THE AZORES.
 
  
 FORECAST POSITIONS AND MAX WINDS
  
 INITIAL      26/0300Z 24.3N  29.0W    40 KT
  12HR VT     26/1200Z 25.3N  29.3W    35 KT
  24HR VT     27/0000Z 26.5N  29.6W    30 KT
  36HR VT     27/1200Z 27.8N  30.0W    25 KT...POST-TROP/REMNT LOW
  48HR VT     28/0000Z 29.2N  30.6W    25 KT...POST-TROP/REMNT LOW
  72HR VT     29/0000Z 31.0N  31.0W    25 KT...POST-TROP/REMNT LOW
  96HR VT     30/0000Z 32.0N  31.0W    20 KT...POST-TROP/REMNT LOW
 120HR VT     01/0000Z...DISSIPATED
  
 $$
 FORECASTER BLAKE