Tropical Storm OTTO

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TROPICAL STORM OTTO DISCUSSION NUMBER  17
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL   AL172010
500 AM AST SUN OCT 10 2010
 
THE SATELLITE PRESENTATION OF OTTO CONTINUES TO DETERIORATE.  THE
LOW-LEVEL CENTER IS NOW COMPLETELY EXPOSED TO THE SOUTH OF A LARGE
SHIELD OF CIRRUS AND A FEW BURSTS OF CONVECTION...AND THE CYCLONE IS
LOOKING INCREASINGLY EXTRATROPICAL.  THE INTENSITY IS SET AT 55 KT
BASED ON A DVORAK ESTIMATE OF T3.0/4.0 FROM TAFB.  STRONG VERTICAL
SHEAR AND COLDER WATERS ARE EXPECTED TO CONTINUE WEAKENING
OTTO...AND THE NHC INTENSITY FORECAST IS BASED ON A BLEND OF THE
GFS...GFDL...AND HWRF MODELS.  THESE MODELS PROBABLY HAVE A BETTER
HANDLE ON THE MID-LATITUDE ENVIRONMENT THAN THE SHIPS/LGEM
MODELS...WHICH APPEAR TO WEAKEN THE CYCLONE TOO FAST.  IT SHOULD BE
NOTED THAT THE GFS AND ECMWF RE-ENERGIZE OTTO BY THE END OF THE
FORECAST PERIOD...SO THE OFFICIAL FORECAST COULD BE A LITTLE LOW ON
DAYS 4 AND 5.
 
OTTO IS EMBEDDED WITHIN STRONG FLOW TO THE SOUTH OF A MID/
UPPER-LEVEL TROUGH AND IS MOVING 65 DEGREES AT 34 KT.  THE FLOW
AHEAD OF OTTO IS EXPECTED TO SPLIT IN THE NEXT 24-36 HOURS...AND
THIS SHOULD CAUSE THE CYCLONE TO DECELERATE AND TURN
SOUTHEASTWARD...MOVING AROUND THE APEX OF A MID-LEVEL RIDGE
EXTENDING ACROSS THE AZORES.  THE EXTRATROPICAL LOW IS THEN
EXPECTED TO BECOME EMBEDDED WITHIN A LARGE CYCLONIC GYRE CURRENTLY
NEAR WESTERN EUROPE ON DAYS 3 THROUGH 5.  BASED ON THE NEW MODEL
GUIDANCE...THE OFFICIAL TRACK FORECAST IS A LITTLE FASTER THAN THE
PREVIOUS ONE FOR THE FIRST 36 HOURS OR SO.  THE ENTIRE FORECAST
TRACK IS MIRRORED MAINLY ON A CONSENSUS OF THE GFS...ECMWF...
UKMET...AND GFDL.
 
FORECAST POSITIONS AND MAX WINDS
 
INITIAL      10/0900Z 35.3N  45.0W    55 KT
 12HR VT     10/1800Z 38.1N  39.2W    50 KT...POST-TROP/EXTRATROP
 24HR VT     11/0600Z 41.5N  32.4W    45 KT...POST-TROP/EXTRATROP
 36HR VT     11/1800Z 43.4N  27.5W    45 KT...POST-TROP/EXTRATROP
 48HR VT     12/0600Z 42.4N  25.1W    40 KT...POST-TROP/EXTRATROP
 72HR VT     13/0600Z 39.5N  23.5W    35 KT...POST-TROP/EXTRATROP
 96HR VT     14/0600Z 37.0N  21.5W    30 KT...POST-TROP/EXTRATROP
120HR VT     15/0600Z 36.5N  19.0W    30 KT...POST-TROP/EXTRATROP
 
$$
FORECASTER BERG
 
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