635 
 WTNT41 KNHC 180253
 TCDAT1
 TROPICAL STORM FAY DISCUSSION NUMBER  10
 NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL   AL062008
 1100 PM EDT SUN AUG 17 2008
 
 AIR FORCE RECONNAISSANCE REPORTS NEAR 0000 UTC SHOWED LITTLE MOTION
 SINCE THE EARLIER FIXES.  RECENT SATELLITE IMAGERY AND CUBAN RADAR
 DATA IMAGERY INDICATE THAT THE CENTER IS ILL-DEFINED AT THE
 MOMENT...AND SURFACE SYNOPTIC DATA SUGGEST THAT THE CIRCULATION IS
 SOMEWHAT ELONGATED FROM EAST TO WEST.  STRONGEST CONVECTION IS
 OCCURRING JUST TO THE EAST AND NORTHEAST OF THE ESTIMATED CENTER. 
 INITIAL MOTION IS A HIGHLY UNCERTAIN 305/9.  THE TRACK FORECAST
 REASONING IS NOT MUCH DIFFERENT FROM EARLIER TODAY.  FAY IS LIKELY
 TO TURN TOWARD THE NORTH ON THE WESTERN PERIPHERY OF A MID-LEVEL
 RIDGE.  NOAA G-IV JET DATA SHOW MID-TROPOSPHERIC HEIGHT FALLS OVER
 THE SOUTHEASTERN GULF OF MEXICO WHICH ALSO SUPPORTS A TURN TOWARD
 THE NORTH.  SOME OF THE TRACK MODELS SUCH AS THE GFDL MODEL HAVE
 SHIFTED...ONCE AGAIN...TO THE EAST.  THERE HAVE OBVIOUSLY BEEN SOME
 RUN-TO-RUN CONSISTENCY PROBLEMS WITH OUR TRACK GUIDANCE...BUT THIS
 IS OFTEN THE CASE FOR WEAK TROPICAL CYCLONES IN THE MODEL INITIAL
 CONDITIONS.  I HAVE NOT MADE MUCH OF A CHANGE TO THE OFFICIAL
 FORECAST WHICH REMAINS CLOSE TO THE DYNAMICAL MODEL CONSENSUS.
 
 WE HAVE BEEN CARRYING 45 KT FOR THE CURRENT INTENSITY SINCE EARLIER
 TODAY ALTHOUGH THERE HAVE BEEN NO RECENTLY OBSERVED FLIGHT-LEVEL
 WINDS TO SUPPORT THIS VALUE.  HOWEVER IT IS BELIEVED THAT THESE
 WINDS ARE LIKELY OCCURRING IN THE STRONG CONVECTION NORTHEAST OF
 THE CENTER WHICH WAS NOT SAMPLED BY THE AIRCRAFT.  AN UPPER-LEVEL
 LOW OVER THE EXTREME NORTHWESTERN CARIBBEAN SEA IS IMPEDING THE
 OUTFLOW OVER THE WESTERN PORTION OF THE TROPICAL CYCLONE AND MAY
 EVEN BE CAUSING SOME UPPER-LEVEL CONVERGENCE OVER THE STORM.  ON
 THE OTHER HAND...THE SHIPS GUIDANCE INDICATES THAT VERTICAL SHEAR
 WILL DECREASE DURING THE NEXT DAY OR SO.  THEREFORE SOME
 STRENGTHENING IS FORECAST WHILE FAY IS OVER WATER DURING THE
 EARLIER PART OF THE FORECAST PERIOD.  BY 48 HOURS OR SO...SHEAR
 ASSOCIATED WITH AN UPPER-LEVEL TROUGH OVER THE EXTREME EASTERN GULF
 OF MEXICO IS FORECAST TO INCREASE...AND THIS SHOULD LIMIT
 INTENSIFICATION.  THE OFFICIAL INTENSITY FORECAST IS A BLEND OF THE
 LATEST GFDL AND HWRF MODEL PREDICTIONS.  IT SHOULD BE ADDED THAT
 THERE IS LOW CONFIDENCE IN THIS FORECAST HOWEVER.
 
 IT IS IMPORTANT NOT TO FOCUS ON THE EXACT FORECAST TRACK.  A BETTER
 WAY OF ASSESSING YOUR RISK IS TO MAKE USE OF THE WIND SPEED
 PROBABILITIES.  THESE DO NOT CHANGE SIGNIFICANTLY FOR GIVEN
 LOCATIONS WHEN SMALL ADJUSTMENTS ARE MADE TO THE TRACK FORECAST.  
  
 FORECAST POSITIONS AND MAX WINDS
  
 INITIAL      18/0300Z 21.4N  80.6W    45 KT
  12HR VT     18/1200Z 22.3N  81.7W    50 KT...INLAND
  24HR VT     19/0000Z 23.8N  82.7W    55 KT
  36HR VT     19/1200Z 25.3N  82.8W    65 KT
  48HR VT     20/0000Z 27.0N  82.8W    70 KT
  72HR VT     21/0000Z 30.5N  82.5W    50 KT...INLAND
  96HR VT     22/0000Z 34.0N  82.5W    25 KT...INLAND
 120HR VT     23/0000Z 37.5N  82.5W    20 KT...REMNANT LOW
  
 $$
 FORECASTER PASCH/ROBERTS