[Tropical] Tropical Weather Discussion

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AXNT20 KNHC 231745
TWDAT

TROPICAL WEATHER DISCUSSION
NWS NATIONAL HURRICANE CENTER MIAMI FL
205 PM EDT FRI MAR 23 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
1645 UTC.

...ITCZ/MONSOON TROUGH...

THE MONSOON TROUGH EXTENDS ACROSS W AFRICA TO THE COAST OF
SIERRA LEONE AT 8N13W TO 5N17W. THE ITCZ CONTINUES FROM 5N17W
ALONG 2N29W 3N44W TO THE COAST OF BRAZIL NEAR 2N51W. SCATTERED
MODERATE/ISOLATED STRONG CONVECTION IS FROM 1N-6N BETWEEN
10W-16W...AND FROM 1S-4N BETWEEN 19W-31W. SCATTERED MODERATE
CONVECTION IS WITHIN 100 NM N OF THE AXIS BETWEEN 32W-39W.

...DISCUSSION...

GULF OF MEXICO...
STRONG SHOWERS/THUNDERSTORMS ARE STILL IMPACTING THE N CENTRAL
GULF NEAR A SURFACE TROUGH EXTENDING FROM THE FLORIDA PANHANDLE
AT 31N87W TO 27N95W...AS OF 1500 UTC. A STRONG LINE OF STORMS IS
WITHIN 40 NM AHEAD OF THE AXIS N OF 28N. A COLD FRONT TRAILS
BEHIND THE TROUGH EXTENDING FROM LOUISIANA NEAR 30N92W TO SRN
TEXAS AT 27N97W. POSSIBLE ISOLATED SHOWERS ARE ALONG THE AXIS. A
SECOND SURFACE TROUGH IS ALSO IN THE SW GULF. THIS TROUGH IS A
BROKEN OFF PIECE OF THE ONE TO THE N THAT IS A REMNANT OF A
FRONTAL BOUNDARY THAT DISSIPATED OVERNIGHT. THE TROUGH EXTENDS
FROM 22N95W TO 17N92W. POSSIBLE ISOLATED SHOWERS ARE W OF THE
TROUGH TO THE MEXICAN COAST. ALOFT...AN UPPER LEVEL LOW NOW OVER
MISSOURI SUPPORTS THE FRONTAL BOUNDARY AND SURFACE TROUGH TO THE
E OF IT. THE UPPER LOW HAS BEEN SLOW MOVING WHICH HAS KEPT MUCH
OF THE SHOWER/THUNDERSTORM ACTIVITY OVER THE N CENTRAL GULF
COAST. THE REMAINDER OF THE BASIN IS COVERED BY DRY AIR ALOFT
WHICH IS HELPING MAINTAIN FAIR CONDITIONS AND MOSTLY CLEAR
SKIES. EXPECT THE COLD FRONT TO CONTINUE TO SKIM THE NRN GULF AS
IT MAKES ITS WAY EWD ALLOWING SURFACE RIDGING TO REBUILD ACROSS
THE BASIN EARLY NEXT WEEK.

CARIBBEAN SEA...
MUCH OF THE CARIBBEAN IS EXPERIENCING FAIR WEATHER TODAY UNDER
THE INFLUENCE OF DRY AIR ALOFT IN MOSTLY SWLY FLOW. HOWEVER...AN
AREA OF MOISTURE EXTENDING FROM THE CENTRAL ATLC IS IMPACTING
THE NE CARIBBEAN PRODUCING SHOWERS AND ISOLATED THUNDERSTORMS
ACROSS THE VIRGIN ISLANDS...PUERTO RICO...AND HISPANIOLA N OF
17N E OF 71W. SOME ISOLATED SHOWERS ARE ALSO NOTED OVER THE FAR
SE CORNER N OF VENEZUELA. THE REMAINDER OF THE BASIN HAS MOSTLY
CLEAR SKIES WITH A FEW PATCHES OF LOW-LEVEL CLOUDS EMBEDDED IN
THE SURFACE FLOW. TRADEWIND FLOW OF 10-20 KTS IS ACROSS THE
MAJORITY OF THE BASIN WITH SOME STRONGER WINDS NEAR THE COAST OF
COLOMBIA. EXPECT LITTLE CHANGE OVER THE NEXT 24 HOURS WITH
CONTINUED SHOWER ACTIVITY OVER THE NE ISLANDS AND N OF VENEZUELA.

ATLANTIC OCEAN...
SURFACE RIDGING COVERS THE W ATLC ANCHORED BY A 1024 MB HIGH
NEAR 32N67W PROVIDING MOSTLY FAIR WEATHER ACROSS THIS AREA. AN
AREA OF MOISTURE IS TO THE S PRODUCING SHOWERS/THUNDERSTORMS
FROM 18N-22N BETWEEN 49W-63W. THIS AREA OF MOISTURE HAS SHIFTED
SLIGHTLY EWD FROM YESTERDAY. THE RIDGE IS SUPPORTED BY AN UPPER
LEVEL RIDGE OVER THE ERN CONUS ALONG EXTENDING FROM NRN FLORIDA
TO PENNSYLVANIA. A BROAD UPPER LEVEL TROUGH COVERS THE W AND
CENTRAL ATLC EXTENDING FROM AN UPPER LEVEL LOW NEAR 54N42W. A
SECOND AND WEAKER CUT-OFF LOW IS TO THE S NEAR 29N57W.
HOWEVER...DRY AIR ALOFT ACROSS THE DISCUSSION AREA IS KEEPING
CONDITIONS FAIR. AN ELONGATED TROUGH EXTENDS OFF THE MAIN UPPER
LOW INTO THE ERN ATLC ALONG 20W SUPPORTING A WEAK COLD FRONT
ENTERING THE DISCUSSION AREA NEAR 32N24W TO 27N36W. ISOLATED
SHOWERS ARE ALONG THE FRONT. A BROAD UPPER RIDGE COVERS THE
REMAINDER OF THE CENTRAL AND ERN ATLC BETWEEN THE WEAK UPPER LOW
TO THE W AND THE ELONGATED UPPER TROUGH TO THE W. MAINLY WLY
FLOW COVERS THE TROPICAL ATLC.

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

$$
WALTON





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