001 
 WTNT42 KNHC 311435
 TCDAT2
  
 TROPICAL STORM KATIA DISCUSSION NUMBER  10
 NWS NATIONAL HURRICANE CENTER MIAMI FL       AL122011
 1100 AM AST WED AUG 31 2011
  
 KATIA REMAINS A WELL-ORGANIZED TROPICAL CYCLONE WITH DISTINCT
 BANDING FEATURES AND A DEVELOPING CENTRAL DENSE OVERCAST.  DVORAK
 CLASSIFICATIONS ARE T3.5 FROM BOTH AGENCIES AND THE CURRENT
 INTENSITY IS HELD AT 55 KT.  THE SYSTEM HAS A WELL-DEFINED
 UPPER-LEVEL OUTFLOW PATTERN.  AT THE MOMENT...IT DOES NOT APPEAR
 THAT THE DRY AIR ADJACENT TO THE STORM IS BEING ENTRAINED INTO THE
 CIRCULATION.  THE SHIPS MODEL INDICATES THAT VERTICAL SHEAR WILL BE
 WEAK FOR THE NEXT DAY OR TWO WHICH SHOULD FAVOR STRENGTHENING AT
 LEAST FOR THE EARLIER PART OF THE FORECAST PERIOD.  A LARGE
 UPPER-LEVEL LOW TO THE NORTHWEST OF KATIA COULD PLAY A ROLE IN THE
 INTENSITY OF THE TROPICAL CYCLONE IN THE LATTER PART OF THE
 FORECAST PERIOD.  AS NOTED EARLIER...SOME OF THE GLOBAL MODELS
 SUGGEST THAT THIS LOW COULD PRODUCE INCREASING SOUTHWESTERLY SHEAR
 IN 4 TO 5 DAYS WHICH WOULD INHIBIT INTENSIFICATION.  THE OFFICIAL
 INTENSITY FORECAST IS THE SAME AS THAT FROM THE PREVIOUS ADVISORY
 AND IS SLIGHTLY ABOVE THE NUMERICAL CONSENSUS.
 
 KATIA CONTINUES TO MOVE SWIFTLY TOWARD THE WEST-NORTHWEST OR 285/18
 TO THE SOUTH OF A MID-TROPOSPHERIC SUBTROPICAL ANTICYCLONE.  THE
 DYNAMICAL GUIDANCE IS IN RATHER GOOD AGREEMENT ON A CONTINUATION OF
 THIS WEST-NORTHWESTWARD TRACK FOR THE NEXT COUPLE OF DAYS WITH SOME
 DECELERATION AS THE TROPICAL CYCLONE NEARS A WEAKNESS IN THE RIDGE. 
 IN THE LATTER PART OF THE FORECAST PERIOD...MOST OF THE GUIDANCE
 SHOWS A TURN TOWARD THE NORTHWEST AS KATIA APPROACHES THE SOUTHWEST
 SIDE OF THE SUBTROPICAL ANTICYCLONE.  THE OFFICIAL TRACK FORECAST
 FOR THIS ADVISORY PACKAGE IS AN UPDATE OF THE PREVIOUS ONE AND IS
 CLOSE TO THE VARIOUS MODEL CONSENSUS TRACKS.
  
 FORECAST POSITIONS AND MAX WINDS
  
 INIT  31/1500Z 14.2N  40.8W   55 KT  65 MPH
  12H  01/0000Z 14.7N  43.3W   65 KT  75 MPH
  24H  01/1200Z 15.4N  46.3W   75 KT  85 MPH
  36H  02/0000Z 16.2N  48.7W   85 KT 100 MPH
  48H  02/1200Z 17.3N  51.0W   90 KT 105 MPH
  72H  03/1200Z 19.5N  54.5W   95 KT 110 MPH
  96H  04/1200Z 21.5N  57.5W  100 KT 115 MPH
 120H  05/1200Z 23.5N  60.5W  105 KT 120 MPH
  
 $$
 FORECASTER PASCH