[Tropical] Tropical Weather Discussion

[EMWIN Server]

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




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