[Tropical] Tropical Weather Discussion

[EMWIN Server]

AXNT20 KNHC 200545
TWDAT

TROPICAL WEATHER DISCUSSION
NWS NATIONAL HURRICANE CENTER MIAMI FL
205 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 0000 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH
0515 UTC.

...ITCZ/MONSOON TROUGH...

THE MONSOON TROUGH EXTENDS FROM THE AFRICAN COAST NEAR 12N16W TO
07N21W. THE INTERTROPICAL CONVERGENCE ZONE AXIS EXTENDS FROM
07N21W TO THE EQUATOR NEAR 36W THEN TO 03S43W. 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 85W THIS EVENING. THIS RIDGE LIES EAST OF
AN APPROACHING UPPER LEVEL TROUGH CURRENTLY LOCATED OVER THE
INTERMOUNTAIN WEST THAT CONTINUES TO ENCROACH ON THE 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
36N67W THAT EXTENDS A RIDGE AXIS SW TO THE CENTRAL GULF NEAR
27N90W. 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 19/2350 UTC WINDSAT SCATTEROMETER PASS. AS
THE UPPER LEVEL TROUGH SLOWLY MOVES EAST OVER THE NEXT 24 TO 36
HOURS...THE ASSOCIATED COLD FRONT WILL CONTINUE TRACKING EAST
ACROSS INLAND PORTIONS OF TEXAS AND OKLAHOMA MERGING WITH
SECONDARY ENERGY FARTHER WEST AND 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.

CARIBBEAN SEA...
CONFLUENT 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 17N70W AND WATER
VAPOR IMAGERY INDICATES THAT DRY AIR AND SUBSIDENCE COVERS THE
BASIN W OF 70W. 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 N OF 16N W OF 83W.
EAST OF THE TROUGH AXIS AND 70W...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 70W. 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 32N50W TO 28N65W TO 20N71W AND INTO THE
NORTH-CENTRAL CARIBBEAN SEA. THE NORTHEASTERN PORTION OF THIS
TROUGH AXIS SUPPORTS A COLD FRONT ANALYZED TO 32N39W THEN
CONTINUING SW AS A SURFACE TROUGH TO 26N52W. WIDELY SCATTERED
SHOWERS ARE OCCURRING WITHIN 120 NM EITHER SIDE OF THE SURFACE
TROUGH AND FROM 21N-27N BETWEEN 45W-57W. OTHERWISE...EAST OF THE
SURFACE TROUGH...THE SW NORTH ATLC REMAINS UNDER THE INFLUENCE
OF A 1026 MB HIGH CENTERED NEAR 36N67W WITH ONLY A FEW ISOLATED
SHOWERS OCCURRING WITHIN EASTERLIES FROM 22N-26N BETWEEN
67W-74W. THE REMAINDER OF THE EASTERN ATLC IS INFLUENCED BY A
SURFACE RIDGE ANCHORED BY A 1039 MB HIGH CENTERED W OF FRANCE
NEAR 47N05W. THE RIDGE AXIS EXTENDS FROM THE HIGH TO 45N13W TO
32N24W TO 27N40W.

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

$$
HUFFMAN




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