[Tropical] Tropical Weather Discussion

[EMWIN Server]

AXNT20 KNHC 060544
TWDAT

TROPICAL WEATHER DISCUSSION
NWS NATIONAL HURRICANE CENTER MIAMI FL
105 AM EST TUE MAR 06 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 ACROSS W AFRICA TO A 1008 MB LOW NEAR
13N15W CONTINUING SW TO 4N22W. THE ITCZ CONTINUES FROM 4N22W
CROSSING THE EQUATOR AT 32W TO THE COAST OF BRAZIL NEAR 4S42W.
SCATTERED MODERATE CONVECTION IS FROM 3S-4N BETWEEN
23W-26W...AND FROM 1S-5N BETWEEN 30W-32W.

...DISCUSSION...

GULF OF MEXICO...
A DRY AND STABLE AIRMASS SITS OVER THE GULF OF MEXICO TONIGHT
PROVIDING MOSTLY FAIR WEATHER BASIN-WIDE. SURFACE RIDGING
DOMINATES ANCHORED BY A 1029 MB HIGH S OF LOUISIANA NEAR 29N90W.
LIGHT ANTI-CYCLONIC FLOW IS AROUND THE HIGH WITH WIND SPEEDS
INCREASING RADIALLY FROM THE CENTER REACHING 20 KTS IN THE SE
GULF. THE SURFACE RIDGE IS SUPPORTED BY AN UPPER LEVEL RIDGE
OVER MEXICO AND THE CENTRAL CONUS. WATER VAPOR IMAGERY INDICATES
DRY AIR ALOFT AND STRONG SUBSIDENCE OVER THE BASIN...WHICH ARE
HELPING SUPPORT CLEAR SKIES ACROSS THE MAJORITY OF THE AREA
BESIDES A FEW PATCHES OF STRATOCUMULUS CLOUDS IN THE SW GULF.
BROAD UPPER TROUGHING COVERS THE ERN HALF OF THE BASIN
SUPPORTING A SECONDARY COLD FRONT THAT PUSHED INTO THE W ATLC
AND ACROSS NRN FLORIDA. THE MAIN FRONT CONTINUES TO MOVE THROUGH
THE CENTRAL ATLC. EXPECT THE SURFACE HIGH TO MERGE WITH A HIGH
TO THE N AND STRENGTHEN...WHICH WILL INCREASE SURFACE RETURN
FLOW ACROSS THE GULF.

CARIBBEAN SEA...
A SHEAR AXIS...REMNANTS OF A FRONTAL BOUNDARY...CONTINUE TO
IMPACT THE NW CARIBBEAN. THE AXIS EXTENDS FROM ERN CUBA NEAR
21N76W TO NRN HONDURAS AT 16N86W. SCATTERED SHOWERS/ISOLATED
THUNDERSTORMS ARE WITHIN 100 NM N OF THE AXIS NEAR HONDURAS
BETWEEN 82W-87W. POSSIBLE ISOLATED SHOWERS ALSO EXTEND NW OF THE
AXIS TO THE YUCATAN CHANNEL WHERE LOW-LEVEL CLOUD COVER IS
PRESENT. A FEW ISOLATED SHOWERS ARE ALSO WITHIN 100 NM S OF THE
AXIS ACROSS JAMAICA BETWEEN 75W-80W. BESIDES MOISTURE IN THE NW
CARIBBEAN...THE REMAINDER OF THE BASIN IS UNDER DRY AIR ALOFT
AROUND A BROAD UPPER LEVEL RIDGE OVER THE CENTRAL AND ERN
CARIBBEAN...WHICH IS HELPING MAINTAIN CLEAR SKIES AND FAIR
CONDITIONS BESIDES SOME LOW-LEVEL CLOUD COVER ACROSS THE SW
CARIBBEAN. TRADEWIND FLOW OF 20-25 KTS IS ACROSS THE ERN AND
CENTRAL CARIBBEAN REACHING 30 KTS NEAR THE COAST OF COLOMBIA.
GALE FORCE WINDS ARE EXPECTED TO BEGIN NEAR THE COAST BY 0600
UTC. EXPECT THE SHEAR AXIS TO REMAIN STATIONARY BEFORE
DISSIPATING LATER TODAY.

ATLANTIC OCEAN...
AN UPPER LEVEL TROUGH IS OVER THE W ATLC ALONG 72W SUPPORTING A
PAIR OF COLD FRONTS. THE PRIMARY FRONT ENTERS THE DISCUSSION
AREA NEAR 32N60W EXTENDING TO 27N67W WHERE IT TRANSITIONS INTO A
SHEAR AXIS TO ERN CUBA AT 21N76W. ISOLATED SHOWERS ARE WITHIN
160 NM BEHIND THE FRONT AND SHEAR AXIS. THE SECONDARY FRONT
ENTERS THE AREA NEAR 32N75W TO NRN FLORIDA NEAR 30N80W. POSSIBLE
ISOLATED SHOWERS ARE ALONG THE AXIS. THE CENTRAL ATLC IS
DOMINATED BY SURFACE RIDGING AROUND A 1031 MB HIGH NEAR 35N42W.
THE RIDGE IS SUPPORTED BY AN UPPER LEVEL RIDGE EXTENDING FROM
THE NE CARIBBEAN TO THE NE NEAR 44N34W. AN UPPER LEVEL LOW IS TO
THE E CENTERED NEAR 32N29W WITH AXIS EXTENDING TOWARDS THE
WINDWARD ISLANDS. THE UPPER LOW SUPPORTS A 1021 MB LOW NEAR
33N29W. A SURFACE TROUGH EXTENDS FROM THE LOW CENTER TO 29N32W.
POSSIBLE ISOLATED SHOWERS ARE E OF THE AXIS N OF 29N BETWEEN
26W-31W. UPPER LEVEL RIDGING COVERS THE TROPICAL ATLC CENTERED
OVER W AFRICA NEAR 8N4W.

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

$$
WALTON





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