[Tropical] Tropical Cyclone Discussion

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WTNT42 KNHC 080859
TCDAT2

HURRICANE KATIA DISCUSSION NUMBER  40
NWS NATIONAL HURRICANE CENTER MIAMI FL       AL122011
1100 PM AST WED SEP 07 2011

NOAA BUOY 41048 HAS PROVIDED VERY VALUABLE DATA IN ESTIMATING THE
INITIAL INTENSITY OF KATIA.  AS THE CENTER OF THE HURRICANE
APPROACHED...THIS DATA BUOY REPORTED PEAK SUSTAINED WINDS OF 76 KT.
THEREFORE THE CURRENT INTENSITY ESTIMATE IS INCREASED TO 80 KT.
THE MINIMUM CENTRAL PRESSURE WAS REDUCED TO 970 MB...ALSO BASED ON
OBSERVATIONS FROM THIS BUOY.

NUMERICAL GUIDANCE INDICATES THAT KATIA WILL REMAIN AN INTENSE
CYCLONE...OR WEAKEN ONLY SLIGHTLY...FOR MOST OF THE FORECAST
PERIOD. THE GLOBAL MODELS DEPICT THE SYSTEM AS A LARGE AND POWERFUL
EXTRATROPICAL CYCLONE OVER THE NORTH ATLANTIC OVER THE NEXT SEVERAL
DAYS.

THE HURRICANE HAS TURNED NORTHWARD...350/12...AS IT MOVES ON THE
WESTERN SIDE OF A SUBTROPICAL CYCLONE AND TO THE EAST OF A
MID-TROPOSPHERIC TROUGH OVER THE OHIO VALLEY.  THERE IS LITTLE
CHANGE TO EITHER THE TRACK FORECAST OR THE REASONING BEHIND IT.  A
SUBSTANTIAL INCREASE IN FORWARD SPEED IS FORECAST AS KATIA OR ITS
POST-TROPICAL COUNTERPART BECOMES ENTRAINED INTO THE MID-LATITUDE
WESTERLIES.  INDEED...BY THE END OF THE FORECAST PERIOD THE SYSTEM
IS FORECAST TO BE NEARING THE NORTHERN UNITED KINGDOM.

FORECAST POSITIONS AND MAX WINDS

INIT  08/0300Z 30.8N  70.0W   70 KT  80 MPH
 12H  08/1200Z 32.5N  70.2W   70 KT  80 MPH
 24H  09/0000Z 35.2N  69.5W   70 KT  80 MPH
 36H  09/1200Z 37.9N  67.0W   70 KT  80 MPH
 48H  10/0000Z 40.4N  61.0W   70 KT  80 MPH
 72H  11/0000Z 46.6N  40.6W   65 KT  75 MPH...POST-TROP/EXTRATROP
 96H  12/0000Z 55.0N  22.0W   65 KT  75 MPH...POST-TROP/EXTRATROP
120H  13/0000Z 60.0N   6.0W   55 KT  65 MPH...POST-TROP/EXTRATROP

$$
FORECASTER CANGIALOSI/PASCH
 WWWW
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