769 
 WTNT42 KNHC 091435
 TCDAT2
 HURRICANE OTTO DISCUSSION NUMBER  14
 NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL   AL172010
 1100 AM AST SAT OCT 09 2010
  
 THE CLOUD PATTERN ASSOCIATED WITH OTTO HAS GRADUALLY BEEN DECREASING
 IN ORGANIZATION DURING THE LAST SEVERAL HOURS.  THE CENTRAL DENSE
 OVERCAST THAT THE CYCLONE HAD BEEN MAINTAINING HAS BECOME
 INCREASINGLY DISTORTED...AND CONVECTIVE CLOUD TOPS HAVE WARMED.  A
 SERIES OF MICROWAVE OVERPASSES SUGGEST THAT THE CENTER IS LOCATED
 ON THE SOUTHWEST SIDE OF THE DEEPEST CONVECTION...AND GIVE EVIDENCE
 OF A PRONOUNCED TILT OF THE VORTEX DUE TO THE EFFECT OF MODERATE
 SOUTHWESTERLY SHEAR.  THE INITIAL INTENSITY IS LOWERED TO 65 KT
 BASED UPON DVORAK T-NUMBERS OF 3.5 AND 4.0 FROM SAB AND TAFB...
 RESPECTIVELY.  FURTHER WEAKENING IS LIKELY OVER THE NEXT SEVERAL
 DAYS AS OTTO ENTERS A STRONGLY SHEARED ENVIRONMENT AND MOVES OVER
 PROGRESSIVELY COOLER WATERS.  GLOBAL MODELS SUGGEST THAT
 EXTRATROPICAL TRANSITION MAY HAVE ALREADY BEGUN...AND THE COMPLETION
 OF THIS PROCESS...ALTHOUGH STILL A BIT UNCERTAIN...IS FORECAST BY
 ABOUT 48 HOURS.  THE OFFICIAL INTENSITY FORECAST IS ADJUSTED
 DOWNWARD BASED UPON RECENT TRENDS AND IS IN GOOD AGREEMENT
 WITH THE STATISTICAL-DYNAMICAL GUIDANCE.
  
 THE MICROWAVE FIXES WERE HELPFUL IN FINDING THE CENTER OF OTTO AND
 SUGGEST THAT THE HURRICANE HAS CONTINUED TO ACCELERATE...WITH AN
 INITIAL MOTION ESTIMATE OF 055/25.  OTTO IS FORECAST TO ACCELERATE
 FURTHER ON A GENERALLY NORTHEASTWARD COURSE DURING THE NEXT 24-36
 HOURS IN BETWEEN A LARGE DEEP-LAYER TROUGH OVER THE NORTHWEST
 ATLANTIC AND A SUBTROPICAL RIDGE TO ITS EAST.  ONCE POST-
 TROPICAL...OTTO IS EXPECTED TO ABRUPTLY DECELERATE AND TURN
 EASTWARD AND SOUTHEASTWARD AS IT ROUNDS THE TOP OF A SHORTWAVE
 RIDGE AND DIVES INTO THE WEST SIDE OF A TROUGH OVER THE NORTHEAST
 ATLANTIC.  ALTHOUGH THE MODEL GUIDANCE CONTINUES TO HAVE DIFFICULTY
 IN PREDICTING THE SHARPNESS OF THIS TURN...THE SPREAD IN THE MODEL
 SOLUTIONS HAS DECREASED SOME SINCE THE LAST CYCLE.  THE OFFICIAL
 TRACK FORECAST IS BASICALLY AN UPDATE OF THE PREVIOUS ONE AND IS
 CLOSE TO THE MULTI-MODEL CONSENSUS.
   
  
 FORECAST POSITIONS AND MAX WINDS
  
 INITIAL      09/1500Z 30.7N  55.7W    65 KT
  12HR VT     10/0000Z 32.9N  51.4W    60 KT
  24HR VT     10/1200Z 36.2N  44.2W    55 KT
  36HR VT     11/0000Z 39.7N  36.7W    50 KT
  48HR VT     11/1200Z 42.5N  31.0W    45 KT...POST-TROP/EXTRATROP
  72HR VT     12/1200Z 43.0N  26.0W    35 KT...POST-TROP/EXTRATROP
  96HR VT     13/1200Z 39.6N  24.0W    30 KT...POST-TROP/EXTRATROP
 120HR VT     14/1200Z 36.5N  21.5W    30 KT...POST-TROP/EXTRATROP
  
 $$
 FORECASTER KIMBERLAIN