000
AXNT20 KNHC 201043
TWDAT 

TROPICAL WEATHER DISCUSSION
NWS NATIONAL HURRICANE CENTER MIAMI FL
805 AM EDT TUE MAR 20 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 0600 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 
1015 UTC.

...ITCZ/MONSOON TROUGH...

THE MONSOON TROUGH EXTENDS FROM THE AFRICAN COAST NEAR 12N17W TO 
08N20W. THE INTERTROPICAL CONVERGENCE ZONE AXIS EXTENDS FROM 
08N20W TO 02N27W TO THE EQUATOR NEAR 39W THEN TO 02S44W. NO 
SIGNIFICANT CONVECTION NOTED.

...DISCUSSION...

GULF OF MEXICO...
AN UPPER LEVEL RIDGE HAS SHIFTED EASTWARD OVER THE PAST 24 HOURS 
WITH AN AXIS NOW ALONG 83W THIS MORNING. THIS RIDGE LIES EAST OF 
AN APPROACHING UPPER LEVEL TROUGH CURRENTLY LOCATED OVER THE 
INTERMOUNTAIN WEST AND SOUTHERN PLAINS WITH PLENTY OF MIDDLE TO 
UPPER LEVEL ENERGY ASSOCIATED WITH IT. AT THE SURFACE...THE 
UPPER LEVEL RIDGING SUPPORTS A 1026 MB HIGH ANCHORED OVER THE SW 
NORTH ATLC CENTERED NEAR 34N64W THAT EXTENDS A RIDGE AXIS SW TO 
THE CENTRAL GULF NEAR 26N90W. PRIMARILY FRESH TO STRONG SE WINDS 
PREVAIL AS NOTED ON RECENT SHIP...BUOY...AND OIL PLATFORM 
OBSERVATIONS WITH STRONGER WINDS W OF 90W PER A 20/0352 UTC 
ASCAT SCATTEROMETER PASS. AS THE UPPER LEVEL TROUGH SLOWLY MOVES 
EAST OVER THE NEXT 24 TO 36 HOURS...THE ASSOCIATED FRONTAL 
BOUNDARY WILL CONTINUE TRACKING EAST ACROSS INLAND PORTIONS OF 
TEXAS AND OKLAHOMA MERGING WITH SECONDARY ENERGY FARTHER WEST 
THAT IS FORECAST TO EMERGE OFF THE TEXAS AND LOUISIANA COAST 
LATE TUESDAY INTO EARLY WEDNESDAY. SE WINDS ARE FORECAST TO 
REMAIN BRISK IN THE 20 TO 25 KT RANGE UNTIL FRONTAL PASSAGE 
WHERE WINDS WILL SHIFT TO N-NW OVER PORTIONS OF THE WESTERN GULF 
W OF 90W INTO WEDNESDAY. AS OF THIS MORNING...MOSAIC DOPPLER 
RADAR INDICATES A LENGTHY SQUALL LINE EXTENDS OUT AHEAD OF THE 
COLD FRONT FROM 34N95W TO 28N98W THAT WILL CONTINUE MARCHING 
EASTWARD AND INTO THE NW GULF WATERS BY THIS AFTERNOON.

CARIBBEAN SEA...
CONFLUENT WESTERLY UPPER LEVEL FLOW IS ACROSS MUCH OF THE 
WESTERN CARIBBEAN ON THE WESTERN PERIPHERY OF WEAK UPPER LEVEL 
TROUGHING EXTENDING INTO THE NORTH-CENTRAL CARIBBEAN FROM THE SW 
NORTH ATLC. THE TROUGH DIPS SOUTHWARD TO A BASE NEAR 17N69W AND 
WATER VAPOR IMAGERY INDICATES THAT DRY AIR AND SUBSIDENCE COVERS 
THE BASIN W OF 68W. AS A RESULT...CONDITIONS AT THE SURFACE 
REMAIN TRANQUIL AND RELATIVELY CLOUD-FREE WITH THE EXCEPTION OF 
A FEW PASSING HIGH CLOUDS OVER THE NW CARIBBEAN THIS MORNING. 
EAST OF THE TROUGH AXIS AND 68W...SOUTHWESTERLY FLOW ALOFT 
DOMINATES AND WATER VAPOR IMAGERY SHOWS THAT WHILE THE LOW TO 
MIDDLE LEVELS OF THE ATMOSPHERE REMAIN DRY AND SUBSIDENT...UPPER 
LEVEL MOISTURE AND CLOUDINESS CONTINUES TO STREAM NE OVER THE 
LESSER ANTILLES AND SE CARIBBEAN S OF 16N E OF 68W. THE ENTIRE 
BASIN IS UNDER THE INFLUENCE OF MODERATE TO FRESH E-NE TRADES  
WITH HIGHER WINDS TO 25 KT OVER PORTIONS OF THE SOUTHWESTERN AND 
SOUTH-CENTRAL CARIBBEAN IN THE VICINITY OF THE COLOMBIAN COAST. 
THIS SYNOPTIC PATTERN ACROSS THE CARIBBEAN IS EXPECTED TO 
PERSIST THROUGH THE WEEK AS HIGH PRESSURE WILL REMAIN ANCHORED 
OVER THE SW NORTH ATLC.

ATLANTIC OCEAN...
WATER VAPOR IMAGERY INDICATES BROAD UPPER LEVEL TROUGHING IS 
OVER MUCH OF THE SW NORTH ATLC WITH AXIS EXTENDING INTO THE 
DISCUSSION AREA NEAR 32N47W TO 29N63W TO 22N70W AND INTO THE 
NORTH-CENTRAL CARIBBEAN SEA. THE NORTHEASTERN PORTION OF THIS 
TROUGH AXIS SUPPORTS A SURFACE TROUGH ANALYZED FROM 32N39W TO 
28N42W TO 22N52W. WIDELY SCATTERED SHOWERS ARE OCCURRING WITHIN 
150 NM EITHER SIDE OF THE SURFACE TROUGH. OTHERWISE...WEST OF 
THE SURFACE TROUGH...THE SW NORTH ATLC REMAINS UNDER THE 
INFLUENCE OF A 1026 MB HIGH CENTERED NEAR 34N64W WITH ONLY A FEW 
ISOLATED SHOWERS OCCURRING WITHIN EASTERLIES FROM 22N-24N 
BETWEEN 64W-73W. THE REMAINDER OF THE EASTERN ATLC IS INFLUENCED 
BY A SURFACE RIDGE ANCHORED BY A 1038 MB HIGH CENTERED OFFSHORE 
OF EASTERN FRANCE NEAR 48N05W. THE RIDGE AXIS EXTENDS FROM THE 
HIGH TO 44N14W TO 32N23W TO 26N35W.

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

$$
HUFFMAN