000 WTNT42 KNHC 081431 TCDAT2 HURRICANE OTTO DISCUSSION NUMBER 10 NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL AL172010 1100 AM AST FRI OCT 08 2010 SATELLITE IMAGES INDICATE THAT OTTO IS STEADILY INCREASING IN ORGANIZATION. THE CYCLONE HAS DEVELOPED A WELL DEFINED AND LARGE CENTRAL DENSE OVERCAST DURING THE LAST 6-12 HOURS...WITH A CURVED BAND OVER THE SOUTHEAST QUADRANT ATTACHED TO THE MAIN CONVECTIVE MASS. A 1059 UTC SSMIS OVERPASS SHOWED THE DEVELOPMENT OF A MID-LEVEL EYEWALL...ALTHOUGH THE LOW-LEVEL CENTER APPEARS TO BE A BIT TO THE WEST OF THAT FEATURE. DVORAK T-NUMBERS ARE AT 4.0 FROM TAFB AND SAB...AND OTTO IS UPGRADED TO A HURRICANE BASED UPON THESE DATA AND THE EARLIER MICROWAVE OVERPASS. THE SHIPS MODEL OUTPUT INDICATES THAT OTTO SHOULD REMAIN IN A GENERALLY LIGHT SHEAR ENVIRONMENT DURING THE NEXT 24 HOURS AND OVER MARGINALLY WARM WATERS...BOTH OF WHICH SHOULD LEAD TO SOME ADDITIONAL INTENSIFICATION. AFTER THAT...WEAKENING SHOULD OCCUR AS OTTO ENCOUNTERS A RAPID INCREASE IN SOUTHWESTERLY SHEAR AND MOVES OVER PROGRESSIVELY COOLER WATERS. THE OFFICIAL INTENSITY FORECAST IS SIMILAR TO THE PREVIOUS ONE AND CLOSE TO THE SHIPS/LGEM INTENSITY GUIDANCE. OTTO HAS CONTINUED TO ACCELERATE EAST-NORTHEASTWARD...AND THE LATEST FIXES SUGGEST AN INITIAL MOTION OF 060/15. THE TRACK GUIDANCE IS IN GOOD AGREEMENT THAT OTTO SHOULD ACCELERATE FURTHER ON A GENERALLY NORTHEASTWARD COURSE DURING THE NEXT 2-3 DAYS...EMBEDDED IN A SWIFT SOUTHWESTERLY FLOW ASSOCIATED WITH A DEEP LAYER TROUGH COVERING THE NORTHWEST ATLANTIC. BEYOND ABOUT 72 HOURS...OTTO IS EXPECTED TO SEPARATE FROM THE MID-LATITUDE SOUTHWESTERLY FLOW AND TURN EASTWARD AND THEN SOUTHEASTWARD ON THE WEST SIDE OF A TROUGH OVER THE NORTHEAST ATLANTIC AND WESTERN EUROPE. ALTHOUGH THIS SOLUTION IS GENERALLY FAVORED BY GLOBAL MODELS...THERE REMAINS SOME SPREAD IN THE GUIDANCE AS TO WHERE AND WHEN THE EXPECTED TURN TOWARD THE EAST SHOULD OCCUR. THE OFFICIAL FORECAST TRACK IS CLOSE TO THE PREVIOUS ONE THROUGH 48 HOURS AND IS ADJUSTED A BIT TO THE LEFT BEYOND THAT TIME...FOLLOWING THE TREND IN THE GUIDANCE. EXTRATROPICAL TRANSITION WILL LIKELY BEGIN IN ABOUT 48 HOURS ONCE OTTO BECOMES MORE DEEPLY INVOLVED WITH THE FAST-PACED...MID- LATITUDE FLOW TO THE NORTH. THERE IS STILL A FAIR AMOUNT OF UNCERTAINTY REGARDING THE COMPLETION OF THIS PROCESS AS OTTO IS FORECAST TO REMAIN TO THE SOUTH OF THE MAIN BAROCLINIC ZONE OVER THE NORTH ATLANTIC. FORECAST POSITIONS AND MAX WINDS INITIAL 08/1500Z 25.9N 64.0W 65 KT 12HR VT 09/0000Z 27.3N 61.7W 70 KT 24HR VT 09/1200Z 29.7N 57.5W 75 KT 36HR VT 10/0000Z 32.4N 51.9W 70 KT 48HR VT 10/1200Z 35.5N 45.0W 65 KT 72HR VT 11/1200Z 40.0N 31.0W 50 KT...POST-TROP/EXTRATROP 96HR VT 12/1200Z 40.0N 24.0W 40 KT...POST-TROP/EXTRATROP 120HR VT 13/1200Z 37.0N 22.0W 35 KT...POST-TROP/EXTRATROP $$ FORECASTER KIMBERLAIN