000
WTNT43 KNHC 120850
TCDAT3
HURRICANE PAULA DISCUSSION NUMBER   3
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL   AL182010
500 AM EDT TUE OCT 12 2010
 
THE AIR FORCE HURRICANE HUNTERS MEASURED A PEAK FLIGHT-LEVEL WIND OF
65 KT AND A MAXIMUM SFMR-OBSERVED SURFACE WIND OF 62 KT.  IT IS
PROBABLE THAT THE AIRCRAFT DID NOT SAMPLE THE VERY HIGHEST WINDS IN
THE CYCLONE.  MOREOVER...A DROPSONDE IN THE CONVECTIVELY ACTIVE
SOUTHEASTERN EYEWALL SHOWED THAT THE WINDS FROM AROUND 900 MB DOWN
TO THE SURFACE WERE 65-70 KT.  BASED ON THESE DATA...PAULA IS
UPGRADED TO A 65-KT HURRICANE.  SINCE THE SYSTEM WILL BE TRAVERSING
THE WATERS OF THE NORTHWEST CARIBBEAN SEA...THE OCEANIC HEAT
CONTENT WILL REMAIN QUITE HIGH FOR THE NEXT SEVERAL DAYS.  THE
ATMOSPHERIC ENVIRONMENT...HOWEVER...WILL LIKELY BECOME INCREASINGLY
LESS CONDUCIVE FOR INTENSIFICATION AS GLOBAL MODEL PREDICTIONS SHOW
STRONG WEST-SOUTHWESTERLY UPPER-LEVEL WINDS IMPACTING THE TROPICAL
CYCLONE WITHIN A COUPLE OF DAYS AND DRIER AIR PUSHING SOUTHWARD
TOWARD THE CIRCULATION LATER IN THE FORECAST PERIOD.  THE OFFICIAL
INTENSITY FORECAST SHOWS SOME ADDITIONAL STRENGTHENING WITHIN THE
NEXT DAY OR SO FOLLOWED BY STEADY WEAKENING.  THIS IS CLOSE TO THE
CONSENSUS OF THE NUMERICAL INTENSITY GUIDANCE.  IT SHOULD BE NOTED
THAT THE LATEST GFS AND U.K. MET GLOBAL MODEL RUNS IMPLY MORE
WEAKENING IN 3 TO 5 DAYS THAN SHOWN BY THE OFFICIAL FORECAST.
 
AIRCRAFT AND SATELLITE FIXES INDICATE THAT THE MOTION IS BEGINNING
TO LEAN A LITTLE TO THE RIGHT AND IS NOW AROUND 325/9.  LITTLE
CHANGE HAS BEEN MADE TO THE PREVIOUS NHC TRACK FORECAST.  PAULA IS
FORECAST TO TURN NORTH-NORTHWESTWARD AND THEN NORTHWARD AROUND THE
WESTERN PERIPHERY OF A MID- TO UPPER-LEVEL RIDGE OVER THE NORTHERN
CARIBBEAN SEA.  THERE IS CONSIDERABLE SPREAD IN THE TRACK MODEL
GUIDANCE WITH THE GFDL ACCELERATING PAULA EAST-NORTHEASTWARD OVER
THE ATLANTIC IN SEVERAL DAYS AND THE GFS AND ECMWF GUIDANCE TURNING
THE CYCLONE SOUTHWARD OR SOUTHWESTWARD OVER THE NORTHWEST CARIBBEAN
SEA.  THE MODEL SPREAD IS AT LEAST PARTIALLY ATTRIBUTABLE TO THE
PREDICTED INTENSITY.  A STRONGER SYSTEM SUCH AS SHOWN BY THE GFDL
WOULD LIKELY BE STEERED BY THE DEEP-LAYER WEST-SOUTHWESTERLY FLOW
AND A WEAK/SHALLOW CYCLONE SUCH AS SHOWN BY THE GFS AND ECMWF WOULD
LIKELY BE PUSHED SOUTHWARD BY LOW-LEVEL NORTH TO NORTHEASTERLY
WINDS.  SINCE WE EXPECT PAULA TO WEAKEN IN THE LATTER HALF OF
FORECAST PERIOD...THE OFFICIAL TRACK FORECAST KEEPS THE TROPICAL
CYCLONE IN THE NORTHWEST CARIBBEAN FOR THE NEXT 5 DAYS.  AS NOTED
IN EARLIER DISCUSSIONS...CONFIDENCE IN THE LATTER PORTION OF THE
TRACK FORECAST IS LOW.
 
FORECAST POSITIONS AND MAX WINDS
 
INITIAL      12/0900Z 17.6N  85.2W    65 KT
 12HR VT     12/1800Z 18.7N  86.0W    70 KT
 24HR VT     13/0600Z 20.1N  86.5W    80 KT
 36HR VT     13/1800Z 21.0N  86.5W    80 KT
 48HR VT     14/0600Z 21.5N  86.0W    75 KT
 72HR VT     15/0600Z 21.5N  85.0W    60 KT
 96HR VT     16/0600Z 21.5N  84.0W    50 KT
120HR VT     17/0600Z 21.0N  83.5W    40 KT

$$
FORECASTER PASCH/KIMBERLAIN