000
AXNT20 KNHC 121746
TWDAT 

TROPICAL WEATHER DISCUSSION
NWS NATIONAL HURRICANE CENTER MIAMI FL
205 PM EDT MON MAR 12 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 INTERTROPICAL CONVERGENCE ZONE AXIS EXTENDS FROM 05N10W TO 
02N20W TO THE EQUATOR NEAR 38W. WIDELY SCATTERED MODERATE 
CONVECTION IS FROM THE EQUATOR TO 14N BETWEEN 04W-24W.

...DISCUSSION...

GULF OF MEXICO...
WEST-SOUTHWESTERLY UPPER LEVEL FLOW IS OVER THE GULF THIS 
AFTERNOON AS WATER VAPOR IMAGERY INDICATES A MIDDLE TO UPPER 
LEVEL SHORTWAVE TROUGH MOVING ACROSS THE LOWER MISSISSIPPI RIVER 
VALLEY. MOST OF THE DIFFLUENCE ASSOCIATED WITH THIS TROUGHING 
HAS MOVED NORTH OF 30N...HOWEVER A FEW ISOLATED SHOWERS AND 
TSTMS ARE NOTED ON MOSAIC DOPPLER RADAR IMAGERY N OF 29N BETWEEN 
86W-95W. SURFACE RIDGING IS ONCE AGAIN GRADUALLY BUILDING 
WESTWARD ACROSS THE ENTIRE GULF BASIN AND THIS OVERALL SYNOPTIC 
PATTERN OF E-SE WINDS AT THE SURFACE IS EXPECTED TO PERSIST 
THROUGH THE REMAINDER OF THE WEEK AHEAD.

CARIBBEAN SEA...
WEST-SOUTHWESTERLY FLOW ALOFT ALSO COVERS MUCH OF THE CARIBBEAN 
WITH WATER VAPOR IMAGERY INDICATING DRY AIR AND SUBSIDENCE WEST 
OF A LINE FROM 18N62W TO 12N71W. THIS IS RESULTING IS MOSTLY 
CLEAR SKIES AND FAIR CONDITIONS OVER THE WESTERN CARIBBEAN AND 
E-NE TRADES IN THE RANGE OF 15 TO 25 KT...WITH SLIGHTLY HIGHER 
WINDS FORECAST IN THE VICINITY OF THE COLOMBIA COAST. UPPER 
LEVEL MOISTURE EAST OF THE AFOREMENTIONED LINE CONTINUES TO 
ADVECT NORTHEASTWARD AND SHIFT EASTWARD AS AN UPPER LEVEL 
ANTICYCLONIC CIRCULATION REMAINS ANCHORED IN THE TROPICAL NORTH 
ATLC NEAR 02N38W. OTHERWISE...AS E-NE TRADES CONTINUE OVER THE 
EASTERN CARIBBEAN...A FEW ISOLATED SHOWERS ARE NOTED ON VISIBLE 
SATELLITE IMAGERY ACROSS PUERTO RICO...AND THE LESSER ANTILLES 
THIS AFTERNOON.

ATLANTIC OCEAN...
DRY AND STABLE NORTHWESTERLY FLOW ALOFT IS ACROSS MUCH OF THE SW 
NORTH ATLC REGION WHICH IS SUPPORTIVE OF A 1032 MB HIGH CENTERED 
NEAR 35N70W. NE TO E WINDS IN THE RANGE OF 15 TO 20 KT ARE 
OBSERVED ACROSS THE REGION W OF 55W. SANDWICHED BETWEEN THE 
SUBTROPICAL SURFACE RIDGES IS A 1008 MB LOW CENTERED IN THE 
CENTRAL ATLC NEAR 33N48W THAT IS SUPPORTED ALOFT BY AN UPPER 
LEVEL TROUGH WITH AXIS EXTENDING TO 26N ALONG 50W. A COLD FRONT 
EXTENDS S-SW FROM THE LOW ALONG 30N49W TO 21N58W PROVIDING FOCUS 
FOR SCATTERED SHOWERS AND ISOLATED TSTMS FROM 24N TO BEYOND 32N 
BETWEEN 41W AND THE FRONT. THE REMAINDER OF THE EASTERN ATLC IS 
UNDER THE INFLUENCE OF A SURFACE RIDGE ANCHORED BY A 1028 MB 
HIGH CENTERED NEAR 35N31W PROVIDING PERSISTENT E-NE WINDS OFF 
THE COAST OF AFRICA TO 40W. OF NOTE...METEOSAT-9 VISIBLE 
SATELLITE IMAGERY SHOWS A LARGE AREA OF SAHARAN DUST OVER THE 
EASTERN ATLC WATERS MOSTLY REMAINING S OF 27N E OF 41W.

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

$$
HUFFMAN