ZCZC MIATCDAT3 ALL
TTAA00 KNHC DDHHMM
HURRICANE ALBERTO DISCUSSION NUMBER 38
NATIONAL WEATHER SERVICE MIAMI FL
11 AM EDT SUN AUG 13 2000
THE INITIAL MOTION ESTIMATE IS 075/16...ABOUT THE SAME AS BEFORE.
BOTH THE UKMET AND THE AVN SHOW THE HURRICANE GETTING CUT OFF FROM
THE WESTERLIES AND TRACKING ANTICYCLONICALLY AROUND A MID ATLANTIC
RIDGE WHILE SLOWING ITS FORWARD SPEED. THE OFFICAL FORECAST FOLLOWS
THIS REASONING AND IS CLOSE TO THE PREVIOUS ADVISORY.
THERE IS NOT A LOT OF DEEP COLD CONVECTION BUT THE BANDING STRUCTURE
IS STILL WELL-DEFINED. DVORAK T NUMBERS ARE DOWN TO 77 AND 65
KT...WITH CI NUMBERS STILL AT 90 KT. THE INITIAL WIND SPEED IS
DECREASED TO 80 KNOTS BASED ON A COMPROMISE OF THESE NUMBERS AND AN
ASSUMPTION THAT THE SURFACE WIND WILL DECAY OVER COOLER WATER FASTER
THAN THE DVORAK CONSTRAINTS. THE SHIPS INTENSITY GUIDANCE
DISSIPATES THE SYSTEM IN 72 HOURS...BUT MAY HAVE OVERSTATED THE
SHEAR IF THE CYCLONE DETACHES FROM THE WESTERLIES. THE OFFICIAL
FORECAST INTENSITY IS A COMPROMISE BETWEEN THIS GUIDANCE AND THE
PREVIOUS FORECAST. ALTHOUGH THIS FORECAST CALLS FOR EXTRATROPICAL
TRANSITION IN 48 HOURS...A MORE STRAIGHTFORWARD DISSIPATION IS ALSO
POSSIBLE.
FORECASTER FRANKLIN
FORECAST POSITIONS AND MAX WINDS
INITIAL 13/1500Z 38.7N 47.4W 80 KTS
12HR VT 14/0000Z 39.2N 44.4W 70 KTS
24HR VT 14/1200Z 39.5N 41.0W 60 KTS
36HR VT 15/0000Z 39.3N 38.7W 50 KTS
48HR VT 15/1200Z 38.5N 37.0W 45 KTS...EXTRATROPICAL
72HR VT 16/1200Z 37.0N 36.5W 35 KTS...EXTRATROPICAL
NNNN
Problems?