657 
 WTNT41 KNHC 011444
 TCDAT1
 TROPICAL STORM FELIX DISCUSSION NUMBER   4
 NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL   AL062007
 1100 AM EDT SAT SEP 01 2007
  
 RADAR IMAGES FROM MARTINIQUE INDICATED THE CENTER PASSED VERY NEAR
 GRENADA OVERNIGHT...WITH THE ISLAND OBSERVING 1005 MB BEFORE THE
 WEATHER STATION STOPPED REPORTING.  SINCE THAT TIME...SATELLITE AND
 RADAR DATA INDICATE THAT FELIX IS FORMING A SMALL INNER CORE WITH
 TIGHTLY-WOUND BANDS AROUND THE CENTER.  IN FACT...AN AIR FORCE PLANE
 JUST MADE IT TO THE CENTER AND REPORTED FLIGHT LEVEL WINDS OF 69
 KT...CORRESPONDING TO ABOUT 55 KT AT THE SURFACE...AND 55 KT WILL
 BE USED AS THE INITIAL INTENSITY.
  
 ALL ATMOSPHERIC AND OCEANIC PARAMETERS SUPPORT A CONTINUED
 STRENGTHENING OF THE STORM.  WITH SUCH A FAVORABLE ENVIRONMENT...IT
 IS LIKELY THAT FELIX WILL BECOME A POWERFUL HURRICANE BY THE TIME
 IT REACHES THE NORTHWESTERN CARIBBEAN SEA.  THE GFDL/HWRF ONLY
 SLOWLY INTENSIFY THE SYSTEM...BUT THE SHIPS/LGEM MODELS SUGGEST
 THIS STORM COULD BE A MAJOR HURRICANE IN ABOUT 3 DAYS.  THE NHC
 INTENSITY FORECAST GOES WITH THE LATTER SCENARIO AND IS JUST A
 LITTLE LOWER THAN THE STATISTICAL MODELS FOR THIS FORECAST PACKAGE.
  
 FELIX HAS BEEN MOVING BASICALLY TO WEST FOR THE PAST 6-12 HOURS AND
 MY INITIAL MOTION ESTIMATE IS 270/16.  A STRONG RIDGE IS FORECAST
 TO STEER THE STORM A LITTLE NORTH OF DUE WESTWARD FOR THE NEXT FEW
 DAYS. TRACK GUIDANCE IS IN GOOD AGREEMENT ON THIS SCENARIO.  BEYOND
 3 DAYS...THERE IS A QUESTION OF HOW MUCH RIDGING WILL BE PRESENT IN
 THE GULF OF MEXICO.  A FEW MODELS HAVE ENOUGH OF A WEAKNESS IN THE
 RIDGE TO FORCE A WEST-NORTHWEST OR NORTHWEST MOTION NEAR THE END OF
 THE PERIOD. HOWEVER...THE RELIABLE GFS/ECMWF ARE KEEPING A STRONG
 RIDGE.  THE OFFICIAL FORECAST IS A LITTLE SOUTH OF THE
 PREVIOUS ONE DUE TO THE WESTWARD MOTION EARLY ON...BUT THEN
 IS VERY CLOSE TO THE PREVIOUS FORECAST BY THE END OF THE PERIOD.
   
 FORECAST POSITIONS AND MAX WINDS
  
 INITIAL      01/1500Z 12.3N  63.6W    55 KT
  12HR VT     02/0000Z 12.8N  66.1W    60 KT
  24HR VT     02/1200Z 13.4N  69.4W    65 KT
  36HR VT     03/0000Z 14.1N  72.9W    70 KT
  48HR VT     03/1200Z 14.8N  76.2W    80 KT
  72HR VT     04/1200Z 16.0N  82.0W    90 KT
  96HR VT     05/1200Z 17.0N  87.0W   100 KT
 120HR VT     06/1200Z 18.5N  91.5W    55 KT...INLAND
  
 $$
 FORECASTER BLAKE/AVILA