HOME	PRODUCTS	FORECASTS	IMAGERY	ABOUT TPC	RECONNAISSANCE

ZCZC MIATCDAT3 ALL
TTAA00 KNHC DDHHMM
TROPICAL STORM ALBERTO DISCUSSION NUMBER  21
NATIONAL WEATHER SERVICE MIAMI FL
5 AM EDT WED AUG 09 2000

IR SATELLITE IMAGES CONTINUE TO SHOW A CLOUD PATTERN PARTIALLY
DISRUPTED BY SOUTHEASTERLY SHEAR...LIMITED DEEP CONVECTION AND MOST
OF THE OUTFLOW TOWARD THE NORTHWEST.  INITIAL INTENSITY REMAINS AT
60 KNOTS AND BECAUSE WATER VAPOR IMAGES SUGGEST THAT ALBERTO
CONTINUES WITHIN A HOSTILE ENVIRONMENT...SOME ADDITIONAL WEAKENING
IS POSSIBLE DURING THE NEXT 12 TO 24 HOURS.  HOWEVER...AN UPPER-
LOW...CURRENTLY NEAR ALBERTO IS FORECAST BY THE GLOBAL MODELS TO
MOVE TOWARD THE SOUTHWEST AWAY FORM THE TROPICAL CYCLONE.  IF
ALBERTO SURVIVES...AND MOST LIKELY IT WILL...THE TROPICAL CYCLONE
WILL THEN BE OVER WARMER WATERS AND WITHIN AN UPPER-LEVEL
ENVIRONMENT MORE FAVORABLE FOR STRENGTHENING.  IN FACT...THE GFDL
AND THE GFDN MODELS LOWER THE PRESSURE TO AROUND 960 AND 940 MB
RESPECTIVELY WHILE SHIPS BRINGS ALBERTO TO 79 KNOTS BY 72 HOURS. 
THE OFFICIAL INTENSITY FORECAST CALLS FOR 75 KNOTS BY THE END OF THE
FORECAST PERIOD.   

THE LOW-LEVEL CENTER IS DIFFICULT TO LOCATE...BUT THE BEST
ESTIMATE OF THE INITIAL MOTION IS 320/12.  THE HIGH PRESSURE RIDGE
TO THE NORTH OF ALBERTO IS FORECAST TO GRADUALLY SHIFT EASTWARD AS A
NEW TROUGH DEVELOPS ALONG THE EAST COAST OF THE UNITED STATES.  THIS
PATTERN FAVORS A NORTHWEST TRACK THROUGH THE FORECAST PERIOD IN
AGREEMENT WITH GUIDANCE. ON THIS TRACK ALBERTO WILL CONTINUE OVER
OPEN WATERS.  

FORECASTER AVILA
 
FORECAST POSITIONS AND MAX WINDS
 
INITIAL     09/0900Z 20.8N  48.7W    60 KTS
12HR VT     09/1800Z 22.1N  50.2W    55 KTS
24HR VT     10/0600Z 23.5N  52.5W    55 KTS
36HR VT     10/1800Z 25.0N  54.5W    60 KTS
48HR VT     11/0600Z 27.0N  56.0W    65 KTS
72HR VT     12/0600Z 31.5N  59.0W    75 KTS
 
 
NNNN