000
AXNT20 KNHC 271750
TWDAT 

TROPICAL WEATHER DISCUSSION
NWS NATIONAL HURRICANE CENTER MIAMI FL  
205 PM EDT SUN MAR 27 2011

TROPICAL WEATHER DISCUSSION FOR NORTH AMERICA...CENTRAL 
AMERICA...GULF OF MEXICO...CARIBBEAN SEA...NORTHERN SECTION 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.

...ITCZ...

ITCZ AXIS IS CENTERED FROM NRN LIBERIA NEAR 7N11W ALONG 4N20W 
EQ29W CONTINUING ALONG THE EQUATOR TO 45W AND INTO NRN BRAZIL TO 
2S50W. SCATTERED MODERATE/STRONG CONVECTION IS WITHIN 150 NM N 
OF THE AXIS BETWEEN 31W-47W...AND WITHIN 200 NM S OF THE EQUATOR 
BETWEEN 36W-46W. 

...DISCUSSION...

GULF OF MEXICO...
MOSTLY FAIR WEATHER IS ACROSS THE GULF OF MEXICO TODAY WITH 
CLEAR SKIES ACROSS MUCH OF THE SRN HALF OF THE BASIN. ALOFT...AN 
UPPER LEVEL RIDGE EXTENDS NWD FROM THE YUCATAN PENINSULA DRAWING 
TROPICAL MOISTURE FROM THE E PACIFIC ACROSS CENTRAL MEXICO AND 
THE NRN GULF. THIS AREA OF MOISTURE IS SUPPORTING SOME HIGH 
CLOUDS N OF 27N WITH DRY AIR ALOFT TO THE S SUPPORTING THE CLEAR 
SKIES. WHILE A SURFACE RIDGE EXTENDS WWD ACROSS THE AREA FROM 
THE CENTRAL ATLC...A LOW PRESSURE SYSTEM LIES JUST N OF THE GULF 
COAST SUPPORTING AREAS OF STRONG SHOWERS STILL NORTH OF THE 
AREA. A FEW ISOLATED SHOWERS ARE NOTED S OF MOBILE ALABAMA. THIS 
SYSTEM IS EXPECTED TO DRIFT SE AS THE SURFACE RIDGE SHIFTS E 
BRINGING SHOWERS/THUNDERSTORMS TO THE NRN GULF BEFORE 
DISSIPATING LATE MONDAY ALLOWING THE SURFACE RIDGE TO BUILD BACK 
IN. 

CARIBBEAN SEA...
STRONG SUBSIDENCE AND DRY AIR ALOFT ARE MAINTAINING FAIR 
CONDITIONS ACROSS THE CARIBBEAN TODAY.  UPPER LEVEL RIDGING 
COVERS THE ERN HALF OF THE BASIN ANCHORED OVER THE TROPICAL ATLC 
WHILE A WEAK UPPER TROUGH IS OVER THE NW CARIBBEAN...BUT DUE TO 
THE EXTREMELY DRY AIR ALOFT...NO SIGNIFICANT WEATHER IS 
ASSOCIATED WITH IT. THE RELATIVELY STRONG PRESSURE GRADIENT 
BETWEEN HIGH PRESSURE ACROSS THE ATLC AND LOWER PRESSURE OVER 
NRN COLOMBIA IS MAINTAINING STRONG NE-E TRADEWINDS ACROSS MUCH 
OF THE BASIN. EXPECT LITTLE CHANGE OVER THE NEXT SEVERAL DAYS. 

ATLANTIC OCEAN...
MAINLY ZONAL WLY FLOW ALOFT DOMINATES THE ENTIRE ATLC WITH A 
BROAD UPPER LEVEL RIDGE CENTERED OVER THE TROPICAL ATLC NEAR 
4N48W. AT THE SURFACE...AN EQUALLY BROAD SURFACE RIDGE DOMINATES 
THE BASIN ANCHORED AROUND A 1026 MB HIGH CENTERED W OF THE 
CANARY ISLANDS. THIS PATTERN IS SUPPORTING MOSTLY FAIR WEATHER 
ACROSS THE BASIN. A WEAK SURFACE TROUGH IS NOTED ABOUT 650 NM E 
OF THE WINDWARDS ISLANDS ALONG 14N49W TO 11N51W SUPPORTING 
ISOLATED SHOWERS WITHIN 90 NM EITHER SIDE OF THE TROUGH. EXPECT 
A FRONTAL BOUNDARY N OF THE WRN ATLC TO DRIFT SWD OVER THE NEXT 
24 HOURS.

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

$$
WALTON