AXNT20 KNHC 201801
TWDAT 

TROPICAL WEATHER DISCUSSION...
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
205 PM EDT WED AUG 20 2008

TROPICAL WEATHER DISCUSSION FOR NORTH AMERICA...CENTRAL 
AMERICA...GULF OF MEXICO...CARIBBEAN SEA...NORTHERN SECTIONS
OF SOUTH AMERICA...AND ATLANTIC OCEAN TO THE AFRICAN COAST
FROM THE EQUATOR TO 32N. THE FOLLOWING INFORMATION IS BASED
ON SATELLITE IMAGERY...METEOROLOGICAL ANALYSIS...WEATHER 
OBSERVATIONS...AND RADAR.

BASED ON 1200 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 
1715 UTC.

...SPECIAL FEATURES...
TROPICAL STORM FAY IS CENTERED NEAR 28.6N 80.6W OR ABOUT 13 NM 
NORTH OF CAPE CANAVERAL FLORIDA AT 20/1800 UTC AND HAS BEEN 
NEARLY STATIONARY DURING THE PAST FEW HOURS. ESTIMATED MINIMUM 
CENTRAL PRESSURE IS 997 MB. MAXIMUM SUSTAINED WIND SPEED IS 45 
KT WITH GUSTS TO 55 KT. PLEASE SEE THE LATEST NHC THE 
FORECAST/ADVISORY UNDER AWIPS/WMO HEADERS MIATCMAT1/WTNT21 KNHC 
AND PUBLIC ADVISORY UNDER AWIPS/WMO HEADERS MIATCPAT1/WTNT31 
KNHC FOR MORE DETAILS. THE UPPER HIGH ASSOCIATED WITH FAY 
REMAINS ELONGATED N/S FROM WRN CUBA NORTHWARD TO GEORGIA 
PROVIDING OUTFLOW OVER THE W ATLC TO 70W AND THE GULF OF MEXICO 
TO 86W. SCATTERED MODERATE/ISOLATED STRONG CONVECTION IS LOCATED 
OFF THE ERN COAST OF FLORIDA FROM 25N-30N BETWEEN 76W-80W. 
SCATTERED/NUMEROUS SHOWERS REMAIN LOCATED WITHIN 250 NM OF THE 
CENTER IN THE NORTHEAST QUADRANT ACROSS THE ERN COAST OF THE 
FLORIDA PENINSULA N OF 27N TO CHARLESTON SOUTH CAROLINA. FAY 
WILL CONTINUE DRIFTING SLOWLY NORTHWARD WHILE EMBEDDED WITHIN 
VERY WEAK MID-LEVEL STEERING FLOW. FAY IS EXPECTED TO PRODUCE
ADDITIONAL RAINFALL ACCUMULATIONS OF 5 TO 10 INCHES OVER 
EAST-CENTRAL AND NORTHEASTERN FLORIDA...WITH 3 TO 6 INCHES OVER 
SOUTHEASTERN GEORGIA. ISOLATED STORM TOTAL AMOUNTS OF 30 INCHES 
ARE POSSIBLE IN FLORIDA. ACCUMULATIONS OF 3 TO 5 INCHES ARE 
POSSIBLE IN THE NORTHWESTERN BAHAMAS.
 
...TROPICAL WAVES...
TROPICAL WAVE IN THE CENTRAL ATLC IS ALONG 49W/50W S OF 18N 
MOVING W 10-15 KT. NO ASSOCIATED DEEP CONVECTION IS OBSERVED. 

TROPICAL WAVE IN THE CENTRAL CARIBBEAN IS ALONG 70W/71W S OF 20N 
MOVING W NEAR 10 KT. NO ASSOCIATED SHOWERS/CONVECTION ASSOCIATED 
WITH THIS WAVE AS IT MOVES BENEATH STRONG UPPER LEVEL 
SUBSIDENCE. 

...THE ITCZ...
THE ITCZ IS CENTERED ALONG 16N16W 11N30W 11N39W 10N52W 8N60W. 
SCATTERED MODERATE CONVECTION IS MOVING OFF THE W AFRICAN COAST 
FROM 10N-14N BETWEEN 12W-20W. SCATTERED MODERATE TO STRONG 
CONVECTION IS FROM 7N-10N BETWEEN 29W-34W. A 1008 MB LOW IS IN 
THE CENTRAL ATLC NEAR 12N42W EMBEDDED WITHIN THE ITCZ DRIFTING W
NEAR 5 KT. OVERALL PRESENTATION ON SATELLITE IMAGERY CONTINUES 
TO SHOW AN AREA OF DISORGANIZED CONVECTION FROM 11N-13N BETWEEN 
42W-45W.

...DISCUSSION...

GULF OF MEXICO...
ISOLATED SHOWERS REMAIN ACROSS THE SE GULF OF MEXICO W OF 83W 
AND ACROSS THE FLORIDA PENINSULA IN ASSOCIATION WITH T.S. FAY.
AN UPPER LOW REMAINS OVER NE TEXAS WITH TROUGHING EXTENDING INTO 
THE FAR NW GULF. AN UPPER LEVEL RIDGE ANCHORED OFF THE W COAST 
OF MEXICO EXTENDS INTO THE GULF ALONG 21N98W NE TO 24N91W 
GENERATING SCATTERED SHOWERS AND THUNDERSTORMS OVER THE WRN GULF
W OF A LINE FROM VERMILION BAY TO VERACRUZ MEXICO. THE REMAINDER 
OF THE GULF REMAINS RATHER CLEAR DUE TO A NARROW CORRIDOR OF 
HIGHER PRESSURE VALUES EXTENDING FROM THE MISSISSIPPI RIVER 
DELTA TO THE YUCATAN CHANNEL. 

CARIBBEAN SEA...
AN UPPER RIDGE COVERS THE WRN CARIBBEAN W OF 72W WITH THE RIDGE 
AXIS EXTENDING FROM WRN CUBA TO NRN BELIZE AND A SECOND UPPER 
RIDGE ANCHORED IN THE W TROPICAL ATLC COVERING THE ERN 
CARIBBEAN. THE ITCZ AXIS EXTENDS FROM COLOMBIA ALONG THE N COAST 
OF PANAMA ACROSS SRN COSTA RICA INTO THE E PACIFIC GENERATING 
ISOLATED SHOWERS WITH EMBEDDED THUNDERSTORMS WITHIN 90 NM OF A 
LINE FROM 16N78W TO 10N83W. WEAK UPPER LEVEL TROUGH IS ACROSS 
THE FAR SE CARIBBEAN GENERATING SCATTERED SHOWERS AND ISOLATED 
THUNDERSTORMS FROM 9N-14N BETWEEN 60W-66W. THE REMAINDER OF THE 
CARIBBEAN IS DOMINATED BY MODERATE/STRONG SUBSIDENCE AND DRY 
STABLE AIR...THUS CLEAR SKIES ELSEWHERE THIS AFTERNOON. 

ATLANTIC OCEAN...
THE MAIN CONCERN FOR THE W ATLC REMAINS T.S. FAY...SEE SPECIAL 
FEATURES ABOVE. THE ELONGATED UPPER LOW IN THE W/CENTRAL ATLC 
EXTENDS FROM NEAR BERMUDA S TO 18N68W. A WEAK SURFACE TROUGH IS 
BENEATH THE UPPER LOW EXTENDING FROM 31N65W TO 27N68W. A LARGE 
UPPER LOW COVERS MOST OF THE CENTRAL ATLC CENTERED NEAR 20N47W 
WITH A WEAKER UPPER LOW NW OF THE CANARY ISLANDS NEAR 34N18W. 
BOTH OF THESE LOWS ARE BENIGN FEATURES. MODERATE SUBSIDENCE AND 
SOMEWHAT DRY STABLE AIR COVERS THE ATLC E OF 60W GIVING THE 
REMAINDER OF THE AREA FAIR WEATHER CONDITIONS. A SURFACE RIDGE 
CONTINUES TO DOMINATE MOST OF THE ATLC N OF 20N E OF 60W 
ANCHORED BY A SERIES OF HIGHS N OF THE REGION.

$$
HUFFMAN