354 
 WTNT45 KNHC 260845
 TCDAT5
 TROPICAL STORM ERNESTO DISCUSSION NUMBER   7
 NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL   AL052006
 500 AM EDT SAT AUG 26 2006
  
 AN AIR FORCE PLANE HAS BEEN INVESTIGATING ERNESTO AND FOUND THAT THE
 CENTRAL PRESSURE DROPPED TO 999 MB WITH A WELL-ESTABLISHED
 CYCLONIC CIRCULATION. HOWEVER FLIGHT LEVEL WINDS HAVE NOT INCREASED
 MUCH SINCE THE PREVIOUS FLIGHT. IT APPEARS THAT THE CENTER IS
 LOCATED ON THE WESTERN PORTION OF THE LARGE DEEP CONVECTIVE MASS
 DUE TO THE CURRENT SOUTHWESTERLY WIND SHEAR. ALTHOUGH DVORAK
 INTENSITY ESTIMATES SUPPORT 45 KNOTS...THE INITIAL INTENSITY IS
 KEPT AT 40 KNOTS BASED ON AVAILABLE REPORTS FROM THE AIRCRAFT.
 ERNESTO HAS BEEN A FIGHTER AND HAS BEEN ABLE TO SURVIVE THE STRONG
 SHEAR SO FAR. UNANIMOUSLY...ALL GLOBAL MODELS DEVELOP AN
 UPPER-LEVEL RIDGE OVER ERNESTO...A PATTERN WHICH IS CONDUCIVE FOR
 STRENGTHENING. THIS UPPER-LEVEL PATTERN COMBINED WITH THE VERY WARM
 WATERS AHEAD OF THE CYCLONE COULD LEAD TO SIGNIFICANT STRENGTHENING
 OVER THE NEXT FEW DAYS. THIS COULD RESULT IN ERNESTO BECOMING A
 POWERFUL HURRICANE IN THE GULF OF MEXICO. THE INTENSITY FORECAST IS
 LOWER THAN THE GFDL AND VERY SIMILAR TO SHIPS AND FSU
 SUPERENSEMBLE. OF COURSE...THE INTENSITY FORECAST IS HIGHLY
 UNCERTAIN AND STRENGTHENING MAY NOT OCCUR AT ALL IF THE SHEAR DOES
 NOT DECREASE.
  
 FIXES FROM THE RECONNAISSANCE PLANE INDICATE THAT ERNESTO IS MOVING
 TOWARD THE WEST-NORTHWEST OR 285 DEGREES AT 14 KNOTS AROUND THE
 PERIPHERY OF THE SUBTROPICAL RIDGE. THIS GENERAL TRACK IS EXPECTED
 TO CONTINUE THROUGH THE FORECAST PERIOD WITH A DECREASE IN FORWARD
 SPEED IN A DAY OR TWO AS THE RIDGE TO THE NORTH WEAKENS. THE
 OFFICIAL TRACK FORECAST IS IN THE MIDDLE OF THE MODEL ENVELOPE BUT
 CLOSER TO THE GLOBAL MODEL CONSENSUS.
  
 IN SUMMARY...ERNESTO COULD BECOME A POTENTIALLY DANGEROUS HURRICANE
 AS IT MOVES ACROSS THE NORTHWESTERN CARIBBEAN SEA AND THE GULF OF
 MEXICO. INTERESTS IN THESE AREAS SHOULD CLOSELY MONITOR THE
 PROGRESS OF THIS SYSTEM.
  
  
 FORECAST POSITIONS AND MAX WINDS
  
 INITIAL      26/0900Z 14.8N  70.2W    40 KT
  12HR VT     26/1800Z 15.4N  72.2W    50 KT
  24HR VT     27/0600Z 16.6N  74.8W    55 KT
  36HR VT     27/1800Z 18.0N  77.5W    60 KT
  48HR VT     28/0600Z 19.5N  80.0W    70 KT
  72HR VT     29/0600Z 22.0N  83.5W    80 KT
  96HR VT     30/0600Z 24.0N  86.5W    90 KT
 120HR VT     31/0600Z 26.0N  89.0W   100 KT
  
 $$
 FORECASTER AVILA