000
AXNT20 KNHC 210501
TWDAT 

TROPICAL WEATHER DISCUSSION
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL  
205 AM EDT SUN MAR 21 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 0000 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 
0345 UTC...

...ITCZ...

ITCZ AXIS IS CENTERED ALONG 7N11W 6N15W 5N27W CROSSING THE 
EQUATOR NEAR 44W AND INTO NE BRAZIL NEAR 1S47W. SCATTERED/ 
NUMEROUS STRONG CONVECTION IS N OF 3N TO INLAND OVER LIBERIA AND 
SIERRA LEONE BETWEEN 10W-13W. SMALL CLUSTERS OF SCATTERED 
MODERATE/ISOLATED STRONG CONVECTION ARE FROM 2N-5N BETWEEN 
16W-21W. 

...DISCUSSION...

GULF OF MEXICO...
AS OF 0300 UTC...A COLD FRONT ENTERS THE W GULF OVER CENTRAL 
LOUISIANA NEAR ATCHAFALAYA BAY EXTENDING ALONG 26N93W INTO 
MEXICO NEAR TUXPAN THEN NW ALONG THE E SLOPES OF THE SIERRA 
MADRE MOUNTAINS. A SURFACE TROUGH PRECEDES THE FRONT EXTENDING 
FROM THE MISSISSIPPI DELTA OF LOUISIANA ALONG 28N89W TO 22N92W. 
MOSAIC RADAR IMAGERY SHOWS HEAVY RAIN AND SCATTERED 
THUNDERSTORMS WITHIN 150 NM E OF THE SURFACE TROUGH TO INLAND 
OVER THE N GULF COAST FROM THE FLORIDA PANHANDLE NEAR PANAMA 
CITY TO OVER SE LOUISIANA NEAR NEW ORLEANS AND LAKE 
PONTCHARTRAIN AND ISOLATED SHOWERS BETWEEN THE SURFACE TROUGH 
AND THE FRONT. NORTHERLY SURFACE GALE FORCE WINDS ARE W OF THE 
FRONT. THIS SYSTEM IS SUPPORTED BY A LARGE UPPER TROUGH THAT IS 
CENTERED BY AN UPPER LOW OVER NE TEXAS/SE OKLAHOMA AND EXTENDS S 
OVER THE GULF W OF 87W. THIS IS PRODUCING A JETSTREAM WITH WINDS 
OF 90 TO 120 KT ACROSS THE GULF N OF A LINE FROM NEAR TUXPAN 
MEXICO TO TAMPA FLORIDA. STRONG SUBSIDENCE AND DRY STABLE AIR 
ALOFT DOMINATES THE AREA W OF THE FRONT. HOWEVER...OVERCAST LOW 
LEVEL COLD AIR STRATOCUMULUS CLOUDS ARE WITHIN 90 NM W OF THE 
FRONT WITH CLEAR SKIES ALONG THE TEXAS COAST. THE COLD FRONT 
WILL SWEEP ACROSS THE GULF TODAY AND EXITING THE AREA TONIGHT. 

CARIBBEAN SEA...
AS OF 0300 UTC...A DISSIPATING STATIONARY FRONT ENTERS THE 
CARIBBEAN OVER NW HAITI EXTENDING ACROSS E JAMAICA TO NEAR 
15N82W. ISOLATED SHOWERS ARE POSSIBLE OVER HAITI AND PORTIONS OF 
CUBA TONIGHT. AN UPPER RIDGE EXTENDS FROM COSTA RICA NE ACROSS 
THE LEEWARD ISLANDS. HOWEVER...THE ENTIRE CARIBBEAN IS DOMINATED 
BY STRONG SUBSIDENCE AND DRY STABLE AIR ALOFT. EASTERLY TRADE 
WINDS ARE BANKING LOW LEVEL CLOUDS WITH ISOLATED SHOWERS ALONG 
THE COAST FROM CENTRAL PANAMA TO S NICARAGUA S OF 12N W OF 80W. 
THE REMAINDER OF THE CARIBBEAN IS EXPERIENCING FAIR WEATHER 
TONIGHT. 
 
ATLANTIC OCEAN...
BROAD UPPER RIDGE DOMINATES MOST OF THE ATLC WITH THE AXIS 
EXTENDING FROM THE CARIBBEAN ACROSS THE LEEWARD ISLANDS TO 
BEYOND 32N33W. A JETSTREAM WITH WINDS OF 90 TO 140 KT IS N OF A 
LINE FROM ACROSS FLORIDA NEAR MELBOURNE ALONG 30N70W TO 27N50W. 
A SURFACE RIDGE ALSO DOMINATES MUCH OF THE ATLC WITH A WEAKENING 
FRONTAL BOUNDARY BISECTING IT. THE COLD FRONT ENTERS THE 
E/CENTRAL ATLC NEAR 32N47W EXTENDING SW TO 24N60W WHERE IT 
BECOMES STATIONARY TO NW HAITI WHERE IT DISSIPATES IN THE 
CARIBBEAN. SCATTERED SHOWERS ARE WITHIN 120 NM OF LINE FROM 
24N66W TO BEYOND 32N45W AND ISOLATED SHOWERS ARE WITHIN 180 NM W 
OF THE REMAINDER OF THE STATIONARY FRONT. A WEAK 1019 MB LOW IS 
EMBEDDED WITHIN THE SURFACE RIDGE OVER THE W ATLC NEAR 30N69W. 
OTHERWISE...THE REMAINDER OF THE ATLC IS EXPERIENCING FAIR 
WEATHER TONIGHT. 

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

$$
WALLACE