000
AXNT20 KNHC 111750
TWDAT 

TROPICAL WEATHER DISCUSSION
NWS NATIONAL HURRICANE CENTER MIAMI FL
205 PM EDT SUN MAR 11 2012

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...WEATHER OBSERVATIONS...RADAR...AND METEOROLOGICAL 
ANALYSIS.

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

...ITCZ/MONSOON TROUGH...

THE MONSOON TROUGH EXTENDS FROM THE AFRICAN COAST NEAR 05N10W TO 
05N14W. THE INTERTROPICAL CONVERGENCE ZONE AXIS EXTENDS FROM 
05N14W TO THE EQUATOR NEAR 36W. ISOLATED MODERATE CONVECTION IS 
FROM 01N-04N BETWEEN 07W-16W...AND FROM 02N-04N BETWEEN 19W-25W. 

...DISCUSSION...

GULF OF MEXICO...
AN UPPER LEVEL RIDGE IS NOTED OVER THE GULF THIS AFTERNOON AND 
THIS RIDGING IS LOCATED EAST OF AN UPPER LEVEL LOW AND 
ASSOCIATED TROUGH EJECTING EASTWARD OUT OF THE ROCKY MOUNTAINS 
AND INTO THE CENTRAL AND SOUTHERN PLAINS. A DIFFLUENT 
ENVIRONMENT IS OBSERVED ON WATER VAPOR IMAGERY AS UPPER LEVEL 
MOISTURE CONTINUES TO FAN NORTHEASTWARD W OF 96W ACROSS THE GULF 
WATERS AND COASTAL GULF PLAINS. AT THE SURFACE...A VERY SHALLOW 
1015 MB LOW IS CENTERED NEAR 30N96W THAT CONTINUES TO DRIFT 
INLAND OVER EASTERN TEXAS. A FRONTAL BOUNDARY EXTENDS SOUTHWARD 
FROM THE LOW ALONG 29N96W TO 25N97W TO 23N97W BEFORE BECOMING A 
SURFACE TROUGH TO SOUTHERN MEXICO NEAR 18N93W. MOSAIC DOPPLER 
RADAR IMAGERY AND LIGHTNING DATA INDICATE SCATTERED SHOWERS AND 
ISOLATED TSTMS ARE OCCURRING WITHIN 60 NM EITHER SIDE OF THE 
FRONT. EAST TO SOUTHEAST WINDS ARE FORECAST TO PERSIST EAST OF 
THE FRONT THROUGH MUCH OF THE UPCOMING WEEK AHEAD AS A SURFACE 
RIDGE HOLDS STRONG OVER THE SW NORTH ATLC REGION.

CARIBBEAN SEA...
WEAK UPPER LEVEL TROUGHING EXTENDS FROM THE SW NORTH ATLC REGION 
INTO THE WESTERN CARIBBEAN ALONG 22N72W TO NEAR 16N80W. NW FLOW 
ALOFT IS LOCATED ON THE BACK SIDE OF THE TROUGH AND ALONG WITH 
DRY AIR AND STRONG SUBSIDENCE WEST OF A LINE FROM 18N66W TO 
09N78W AS NOTED ON WATER VAPOR IMAGERY...MOSTLY CLEAR SKIES AND 
FAIR CONDITIONS ARE OCCURRING OVER THE WESTERN HALF OF THE 
CARIBBEAN BASIN. E-NE WINDS DOMINATE ON THE SOUTHERN PERIPHERY 
OF A SURFACE RIDGE ANCHORED WELL NORTH OF THE AREA AS A 1037 MB 
HIGH CENTERED OVER THE MID-ATLC COAST. EAST OF THE TROUGH 
AXIS...SOUTHWESTERLY UPPER LEVEL FLOW IS ADVECTING MIDDLE TO 
UPPER LEVEL MOISTURE FROM OVER VENEZUELA ACROSS THE LESSER 
ANTILLES AND EASTWARD OVER THE TROPICAL ATLC S OF 22N. DUE TO 
SUFFICIENT UPPER LEVEL LIFT AND MARGINAL LOW-LEVEL CONVERGENCE 
OF THE EASTERLY TRADES...ISOLATED SHOWERS ARE OCCURRING S OF 16N 
E OF 71W...INCLUDING MANY OF THE LESSER ANTILLES ISLANDS.

ATLANTIC OCEAN...
WATER VAPOR IMAGERY INDICATES AN UPPER LEVEL TROUGH AXIS EXTENDS 
OVER THE WESTERN NORTH ATLC FROM 35N60W TO 27N71W THAT SUPPORTS 
A COLD FRONT EXTENDING INTO THE DISCUSSION AREA NEAR 32N60W 
CONTINUING SW TO 28N67W AND BECOMING A DISSIPATING STATIONARY 
FRONT ALONG 26N72W TO THE FLORIDA PENINSULA COAST NEAR 28N81W. 
ISOLATED SHOWERS ARE OCCURRING WITHIN 60 NM EITHER SIDE OF THE 
FRONT AS IT CONTINUES TO BECOMING MORE DIFFUSE OVER THE NEXT 24 
TO 36 HOURS. A 1037 MB HIGH CENTERED NEAR 37N78W IS EXPECTED TO 
BUILD INTO THE SW NORTH ATLC REGION AS THE FRONT N OF 30N MOVES 
EAST. MODERATE TO STRONG E-NE WINDS WILL PERSIST ON THE SOUTHERN 
PERIPHERY OF THE RIDGE AS IT SLIDES OFF THE COAST OF THE 
CAROLINAS EARLY MONDAY. SE OF THE COLD FRONT...A 1016 MB LOW IS 
CENTERED NEAR 31N56W WITH A SURFACE TROUGH EXTENDING S-SW FROM 
THE LOW TO 22N61W. MOST CONVECTION ASSOCIATED WITH THE LOW IS 
OCCURRING UNDER MAXIMIZED UPPER LEVEL DIFFLUENCE NORTH AND EAST 
OF THE LOW WITH SCATTERED SHOWERS AND ISOLATED TSTMS OCCURRING 
FROM 26N-35N BETWEEN 51W-56W. THE REMAINDER OF THE CENTRAL AND 
EASTERN ATLC IS UNDER THE INFLUENCE OF A SURFACE RIDGE ANCHORED 
BY A 1029 MB HIGH CENTERED NEAR 34N39W PROVIDING PERSISTENT E-NE 
WINDS OFF THE COAST OF AFRICA TO 50W. OF NOTE...METEOSAT-9 
VISIBLE SATELLITE IMAGERY SHOWS A LARGE AREA OF SAHARAN DUST 
OVER THE EASTERN ATLC WATERS MOSTLY REMAINING S OF 20N E OF 
40W...HOWEVER A 1013 MB SURFACE LOW AND THE REMNANTS OF A 
FRONTAL BOUNDARY HAS SUSPENDED THE DUST OVER A NARROW 90 NM WIDE 
ZONE EXTENDING FROM EAST OF THE LOW NEAR 43N22W TO 36N21W TO 
28N26W. 

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

$$
HUFFMAN