000 WTNT42 KNHC 100850 TCDAT2 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