[Tropical] Tropical Weather Discussion

[EMWIN Server]

AXNT20 KNHC 221729
TWDAT

TROPICAL WEATHER DISCUSSION
NWS NATIONAL HURRICANE CENTER MIAMI FL
805 PM EDT TUE MAR 22 2011

TROPICAL WEATHER DISCUSSION FOR NORTH AMERICA...CENTRAL
AMERICA...GULF OF MEXICO...CARIBBEAN SEA...NORTHERN SECTION OF
SOUTH AMERICA...AND ATLANTIC OCEAN TO THE AFRICAN COAST FROM THE
EQUATOR TO 32N. THE FOLLOWING INFORMATION IS BASED ON SATELLITE
IMAGERY...METEOROLOGICAL ANALYSIS...WEATHER OBSERVATIONS...AND
RADAR.

BASED ON 1200 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH
1715 UTC.

...ITCZ...

ITCZ AXIS IS ANALYZED ALONG 5N8W ALONG THE EQUATOR BETWEEN
18W-44W THEN INTO SOUTH AMERICA SOUTH OF THE EQUATOR. SCATTERED
MODERATE/STRONG CONVECTION IS WITHIN 125 NM S OF THE ITCZ
BETWEEN 10W-14W. SCATTERED MODERATE/ISOLATED STRONG CONVECTION
IS WITHIN 150/180 NM N OF THE ITCZ E OF 13W TO THE COAST OF SW
AFRICA.

...DISCUSSION...

GULF OF MEXICO...
BROAD UPPER RIDGE COVERS THE GULF OF MEXICO ANCHORED IN THE E
BAY OF CAMPECHE WITH THE AXIS EXTENDING N OVER THE MISSISSIPPI
VALLEY. STRONG SUBSIDENCE AND DRY STABLE AIR ALOFT DOMINATES THE
GULF WATERS WITH UPPER LEVEL MOISTURE FROM THE E PACIFIC REGION
BEING DRAWN ACROSS MEXICO AND E TEXAS TO OVER THE SE CONUS. A
SURFACE RIDGE COVERS THE GULF ANCHORED BY A 1021 MB HIGH IN THE
NE GULF NEAR 29N87W AND A 1023 MB HIGH IN THE W ATLC GIVING THE
GULF FAIR WEATHER THIS AFTERNOON. THE 1021 MB HIGH IN THE GULF
WILL DISSIPATE THROUGH WED. THE SURFACE RIDGE WILL REMAIN ACROSS
THE N GULF THROUGH WED NIGHT THEN SHIFT E OF THE GULF LATE THU.

CARIBBEAN SEA...
THE UPPER RIDGE OVER THE GULF OF MEXICO COVERS THE NW CARIBBEAN
GIVING THE AREA NE WINDS ALOFT WITH STRONG SUBSIDENCE AND DRY
STABLE AIR ALOFT W OF A LINE FROM HISPANIOLA TO NE NICARAGUA. A
LARGE UPPER RIDGE ANCHORED OVER THE DEEP TROPICS COVERS THE
REMAINDER OF THE CARIBBEAN GIVING THE AREA E OF THE ABOVE LINE
SW TO W FLOW ALOFT. THE TIGHT PRESSURE GRADIENT OVER THE
CARIBBEAN IS BEING GENERATED BETWEEN THE SURFACE RIDGE OVER THE
GULF OF MEXICO AND THE W ATLC AND THE LOWER PRESSURE OVER THE
TROPICS TO PRODUCE STRONG NE TO E TRADE WINDS ACROSS THE BASIN
WITH THE STRONGEST WINDS ALONG THE COAST OF COLOMBIA. THE UPPER
RIDGE ANCHORED OVER THE TROPICS IS DRAWING TROPICAL MOISTURE
OVER SOUTH AMERICA INTO THE S CARIBBEAN GENERATING SCATTERED TO
NUMEROUS SHOWERS OVER THE SW CARIBBEAN S OF 15N BETWEEN 58W-65W
INCLUDING THE WINDWARD ISLANDS AND WITHIN 75 NM ALONG THE
REMAINDER OF THE SOUTH AMERICAN COAST E OF 74W. LOW LEVEL
MOISTURE REMAINS ACROSS THE CARIBBEAN GENERATING PATCHES OF
ISOLATED SHOWERS USHERED IN ON THE TRADE WINDS MAINLY N OF 15N
AND OVER THE SW CARIBBEAN S OF 15N W OF 78W. SURFACE RIDGE OVER
THE GULF OF MEXICO AND W ATLC WILL SLIDE SE AND WEAKEN THROUGH
EARLY THU.

ATLANTIC OCEAN...
A SURFACE RIDGE DOMINATES THE W ATLC INTO THE GULF OF MEXICO
ANCHORED BY A 1023 MB HIGH NEAR 28N76W AND A 1021 MB HIGH IN THE
NE GULF OF MEXICO. BROAD UPPER TROUGH COVERS THE W ATLC N OF 20N
W OF 30W SUPPORTING A WELL DEFINED COLD FRONT THAT ENTERS THE
REGION NEAR 32N36W EXTENDING ALONG 22N45W TO 20N55W WHERE IT
BEGINS TO DISSIPATE TO 20N54W WHERE A SURFACE TROUGH CONTINUES
TO NEAR 21N71W. SCATTERED SHOWERS ARE WITHIN 60 NM EITHER SIDE
OF THE FRONT. A SURFACE TROUGH IS TO THE E EXTENDING FROM 32N35W
ALONG 24N36W TO 15N43W. A SHARP UPPER RIDGE IS TO THE E OF THIS
SURFACE TROUGH ENHANCING SCATTERED SHOWERS WITHIN 350 NM E OF
THE SURFACE TROUGH MAINLY N OF 20N. A WEAK SURFACE RIDGE
DOMINATES THE E ATLC ANCHORED BY A 1018 MB HIGH W OF THE CANARY
ISLANDS NEAR 27N25W LEAVING THE REMAINDER OF THE ATLC WITH FAIR
WEATHER THIS AFTERNOON. THE W ATLC COLD FRONT WILL CONTINUE TO
SHIFT ACROSS THE CENTRAL ATLC SLOWLY WEAKENING. THE 1023 MB HIGH
WILL SHIFT SE AND WEAKEN THROUGH WED NIGHT AS A COLD FRONT
PASSES JUST N OF THE AREA.

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

$$
PAW





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