000
WTNT42 KNHC 081507
TCDAT2
 
HURRICANE KATIA DISCUSSION NUMBER  42
NWS NATIONAL HURRICANE CENTER MIAMI FL       AL122011
1100 AM AST THU SEP 08 2011
 

THE CLOUD PATTERN ASSOCIATED WITH KATIA HAS NOT CHANGED MUCH IN THE
PAST SEVERAL HOURS SINCE IT PASSED VERY CLOSE TO A NOAA BUOY. MOST
OF THE CONVECTION REMAINS NORTH AND EAST OF THE CENTER...CONSISTENT
WITH SOME WESTERLY SHEAR AFFECTING THE STORM. THE CURRENT INTENSITY
IS HELD AT 80 KT BASED ON THE PRIOR BUOY OBSERVATION AND CONTINUITY
OF THE CLOUD PATTERN...WITH MINIMUM CENTRAL PRESSURE ALSO HELD AT
970 MB. 

KATIA CONTINUES TO MOVE NORTHWARD...SLIGHTLY FASTER AT 360/15...AND
RELIABLE NUMERICAL GUIDANCE SUGGESTS THAT KATIA WILL GRADUALLY TURN
NORTHEASTWARD AND CONTINUE TO ACCELERATE OVER THE NORTH ATLANTIC
OVER THE NEXT DAY OR SO. THERE IS VERY LITTLE CHANGE TO THE TRACK
FORECAST...WHICH IS CLOSE TO THE MULTI-MODEL CONSENSUS. THE
FORECAST TAKES THE REMNANTS OF KATIA NORTH OF THE BRITISH ISLES IN
ABOUT FOUR DAYS.  THE GLOBAL MODELS INDICATE THAT KATIA WILL REMAIN
A POWERFUL CYCLONE EVEN AS IT INTERACTS WITH A MID-TROPOSPHERIC
TROUGH AND ASSOCIATED STRONG WESTERLIES.  THE GFS INDICATES THAT
EXTRATROPICAL TRANSITION COULD OCCUR A LITTLE SOONER THAN SHOWN
BELOW.  
 
 
FORECAST POSITIONS AND MAX WINDS
 
INIT  08/1500Z 33.6N  70.1W   80 KT  90 MPH
 12H  09/0000Z 35.6N  69.4W   80 KT  90 MPH
 24H  09/1200Z 38.3N  66.8W   80 KT  90 MPH
 36H  10/0000Z 40.7N  61.8W   75 KT  85 MPH
 48H  10/1200Z 43.2N  53.0W   70 KT  80 MPH
 72H  11/1200Z 50.0N  31.0W   65 KT  75 MPH...POST-TROP/EXTRATROP
 96H  12/1200Z 59.0N   9.5W   60 KT  70 MPH...POST-TROP/EXTRATROP
120H  13/1200Z 62.0N   2.0W   50 KT  60 MPH...POST-TROP/EXTRATROP
 
$$
FORECASTER HOGSETT/FRANKLIN