000
AXNT20 KNHC 281056
TWDAT 

TROPICAL WEATHER DISCUSSION
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL  
805 AM EDT WED APR 28 2010

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 0600 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY
THROUGH 1015 UTC...

...THE ITCZ...

FROM THE SIERRA LEONE COAST NEAR 7N12W TO 5N20W TO 5N30W 3N40W...
CROSSING THE EQUATOR ALONG 47W...INTO NORTHEASTERN BRAZIL NEAR
2S51W. STRONG SHOWERS AND THUNDERSTORMS ARE IN THE COASTAL 
WATERS OF BRAZIL BETWEEN 42W AND 46W TO THE SOUTH OF THE 
EQUATOR. ISOLATED TO WIDELY SCATTERED MODERATE SHOWERS AND 
POSSIBLY LOCALLY STRONG THUNDERSTORMS ARE ELSEWHERE TO THE
SOUTH OF 7N IN THE ATLANTIC OCEAN.
 
...DISCUSSION...

FROM THE ATLANTIC OCEAN TO THE WEST OF 60W INTO THE GULF OF 
MEXICO...AND INTO THE NORTHWESTERN CORNER OF THE CARIBBEAN SEA...
BROAD AND GENTLE UPPER LEVEL CYCLONIC FLOW COVERS THE AREA TO 
THE NORTH OF 26N BETWEEN 70W AND FLORIDA. UPPER LEVEL 
ANTICYCLONIC FLOW COVERS PRETTY MUCH ALL THE GULF OF MEXICO...
IT IS ASSOCIATED WITH AN UPPER LEVEL RIDGE IN THE CARIBBEAN SEA.
AN UPPER LEVEL TROUGH IN THE WESTERN ATLANTIC OCEAN GUIDES
A COLD FRONT THAT PASSES THROUGH 32N76W IN THE ATLANTIC OCEAN
TO FLORIDA NEAR 29N82W INTO THE NORTHEASTERN GULF OF MEXICO AND 
ULTIMATELY SOUTHEASTERN LOUISIANA. AN UPPER LEVEL CYCLONIC 
CIRCULATION CENTER IS IN NORTHERN MEXICO NEAR 28N103W JUST TO 
THE SOUTH OF THE TEXAS BIG BEND. BROAD UPPER LEVEL SOUTHWESTERLY 
FLOW COVERS THE REST OF THE ATLANTIC OCEAN TO THE WEST OF 
60W...ON THE EASTERN SIDE OF THE TROUGH AND CYCLONIC FLOW THAT 
ARE ON THE U.S.A. EAST COAST. A SURFACE TROUGH GOES FROM 31N60W 
TO 25N66W. MULTILAYERED CLOUDS AND SHOWERS ARE TO THE NORTH OF 
26N BETWEEN 50W AND 61W. A DISSIPATING STATIONARY FRONT GOES
FROM 30N67W TO 26N70W...ACROSS THE BAHAMAS FROM 22N TO 26N TO 
CENTRAL CUBA...CONTINUING TO THE SOUTHEASTERN CORNER OF THE 
YUCATAN PENINSULA. SHOWERS COVER THE AREA FROM 20N TO 24N 
BETWEEN 70W IN THE ATLANTIC OCEAN AND THE NORTHEASTERN YUCATAN 
PENINSULA IN THE NORTHWESTERN CORNER OF THE CARIBBEAN SEA.
NUMEROUS STRONG SHOWERS AND THUNDERSTORMS ARE IN NORTHERN 
GUATEMALA...SPILLING OVER INTO THE SOUTHERN YUCATAN PENINSULA
A BIT FROM NORTH TO SOUTH...AND IN THE NORTHERN HALF OF 
GUATEMALA. STRONG SHOWERS AND THUNDERSTORMS ALSO ARE IN EASTERN 
EL SALVADOR AND SOUTHERN HONDURAS...ASSOCIATED WITH A SURFACE 
TROUGH THAT RUNS FROM NORTH CENTRAL NICARAGUA...ACROSS HONDURAS 
AND BEYOND WEST CENTRAL GUATEMALA...EVENTUALLY BEYOND THE 
ISTHMUS OF TEHUANTEPEC. BROAD AND WEAK SURFACE ANTICYCLONIC
FLOW COVERS THE REST OF THE GULF OF MEXICO.

THE CARIBBEAN SEA...
THE SHOWERS AND THUNDERSTORMS THAT WERE OCCURRING FROM PANAMA TO 
NICARAGUA IN AN AREA OF DIRECTIONAL WIND SHEAR WITH HEIGHT...
ABUNDANT MOISTURE...AND A LINGERING WEAK SURFACE TROUGH FROM
SIX HOURS AGO HAS DISSIPATED WITH TIME. BROAD UPPER LEVEL
ANTICYCLONIC FLOW COVERS THE AREA.

THE ATLANTIC OCEAN FROM 60W EASTWARD...
AN UPPER LEVEL TROUGH PASSES THROUGH 32N23W TO 29N26W TO 17N34W 
TO 10N47W. THE NORTHERN END OF WHAT WAS A STATIONARY FRONT
SIX HOURS AGO MOVED DURING THE LATE NIGHT/EARLY MORNING HOURS.
THE UPPER LEVEL TROUGH SUPPORTS THE COLD FRONT THAT PASSES OVER 
THE MADEIRA ARCHIPELAGO TO 30N20W AND 25N30W. THE FRONT CONTINUES
AS A STATIONARY FRONT FROM 25N30W TO 20N40W AND 16N44W. SHOWERS 
ARE POSSIBLE WITHIN 60 NM TO 120 NM ON EITHER SIDE OF THE LINE 
THAT PASSES THROUGH 32N19W TO 24N39W. SURFACE ANTICYCLONIC FLOW 
MOVES AROUND A RIDGE THAT PASSES THROUGH A 1026 MB HIGH PRESSURE 
CENTER THAT IS NEAR 34N34W TO 28N45W 25N53W TO 21N60W.

FOR ADDITIONAL INFORMATION PLEASE VISIT 
HTTP://WWW.HURRICANES.GOV/MARINE

$$
MT