[Tropical] Tropical Weather Discussion

[EMWIN Server]

AXNT20 KNHC 200547
TWDAT

TROPICAL WEATHER DISCUSSION
NWS NATIONAL HURRICANE CENTER MIAMI FL
205 AM EDT SUN MAR 20 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 0000 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH
0515 UTC.

...ITCZ...

THE ITCZ AXIS EXTENDS ALONG 05N09W TO THE EQUATOR NEAR 18W THEN
ALONG 01S TO 28W AND INTO NE BRAZIL NEAR 05S37W. SCATTERED
MODERATE CONVECTION IS FROM 03N-06N BETWEEN 04W-17W. ISOLATED
MODERATE CONVECTION IS FROM THE EQUATOR TO 03N BETWEEN 28W-34W.

...DISCUSSION...

GULF OF MEXICO...
AN UPPER LEVEL ANTICYCLONIC CIRCULATION IS CENTERED OVER CENTRAL
MEXICO NEAR 18N101W THAT EXTENDS A RIDGE AXIS NE ACROSS THE
WESTERN GULF AND PORTIONS OF THE SE CONUS. MOSTLY SUBSIDENT
NORTHWESTERLY FLOW ALOFT IS NOTED ON WATER VAPOR IMAGERY WHICH
IS SUPPORTIVE OF A 1024 MB SURFACE HIGH CENTERED OVER THE NE
GULF NEAR 27N84W. SHIP AND BUOY OBSERVATIONS INDICATE EAST TO
SOUTHEAST WINDS IN THE RANGE OF 10 TO 20 KT ARE ACROSS THE GULF
CURRENTLY AND THIS WIND REGIME IS FORECAST TO PERSIST THROUGH
EARLY WEDNESDAY AS THE HIGH REMAINS STATIONARY WITH AXIS ALONG
28N. SKIES ARE EXPECTED TO REMAIN CLEAR THROUGH THE OVERNIGHT
HOURS WITH AREAS OF PATCHY TO DENSE FOG POSSIBLE ALONG THE
IMMEDIATE GULF COAST WATERS W OF 85W.

CARIBBEAN SEA...
MOST OF THE CARIBBEAN SEA BASIN IS UNDER THE INFLUENCE OF A
BROAD UPPER LEVEL RIDGE CENTERED OVER THE TROPICAL ATLC WITH
ASSOCIATED DRY AIR AND SUBSIDENCE. THIS OVERALL PATTERN IS
LIMITING ANY SIGNIFICANT DEEP CONVECTION...WITH ONLY A FEW AREAS
OF TRADEWIND SHOWERS NOTED ON SATELLITE IMAGERY. OF NOTE...AN
AREA OF ISOLATED SHOWERS REMAINS FOCUSED IN THE VICINITY OF A
SURFACE TROUGH ANALYZED FROM 12N61W TO 15N59W EAST OF THE LESSER
ANTILLES. THE ACTIVITY COVERS THE AREA S OF 17N BETWEEN 58W-65W.
ANOTHER AREA OF ISOLATED SHOWERS IS OCCURRING FROM 14N-18N
BETWEEN 81W-90W...INCLUDING INTERIOR PORTIONS OF HONDURAS...
BELIZE...AND GUATEMALA. ALSO...LOW-LEVEL SPEED CONVERGENCE OF
THE TRADES OVER THE SW CARIBBEAN IS GENERATING ISOLATED SHOWERS
S OF 12N W OF 78W ACROSS THE COSTA RICA AND WESTERN PANAMA COAST.

ATLANTIC OCEAN...
SURFACE HIGH PRESSURE LOCATED OVER THE FLORIDA PENINSULA EXTENDS
EASTWARD OVER THE SW NORTH ATLC WATERS MAINTAINING OVERALL FAIR
CONDITIONS FOR THE OVERNIGHT PERIOD W OF 60W. A WEAKENING COLD
FRONT IS ANALYZED INTO THE DISCUSSION AREA NEAR 32N70W TO 32N79W
THEN INLAND NEAR BEAUFORT SOUTH CAROLINA. VERY LITTLE MIDDLE TO
UPPER LEVEL MOISTURE IS ASSOCIATED WITH THE FRONT...HOWEVER...
POSSIBLE ISOLATED SHOWERS ARE WITHIN 60 NM EITHER SIDE OF THE
FRONT AS IT CONTINUES TO MOVE S-SE. AN AREA OF STRONGER NE WINDS
IN THE RANGE OF 20 TO 25 KT RESIDE NORTH OF THE FRONT AS
DEPICTED BY A RECENT 20/0144 UTC ASCAT PASS. FARTHER EAST...AN
UPPER LEVEL SHORTWAVE TROUGH IS ALONG 50W AND SUPPORTS A 1014 MB
LOW CENTERED NEAR 27N51W. A SURFACE TROUGH EXTENDS S-SW FROM THE
LOW ALONG 24N50W TO 19N53W WITH ISOLATED SHOWERS AND POSSIBLE
TSTMS FROM 18N-27N BETWEEN 44W-54W. A WARM FRONT ALSO EXTENDS
EAST FROM THE LOW TO 27N45W. LOW-LEVEL CONVERGENCE GENERATED
FROM THE FRONT ALONG WITH AMPLE MIDDLE TO UPPER LEVEL DIFFLUENCE
IS GENERATING ISOLATED SHOWERS AND TSTMS FROM 27N-31N BETWEEN
43W-53W. A RECENT ASCAT PASS FROM AROUND 20/0000 UTC DEPICTED
THE LOW CIRCULATION WITH STRONG E TO SE WINDS IN THE RANGE OF 20
TO 30 KT COVERING THE AREA FROM 22N-31N BETWEEN 43W-52W. THE
REMAINDER OF THE EASTERN ATLC IS DOMINATED BY A SURFACE RIDGE
ANCHORED ON A 1025 MB HIGH CENTERED NEAR 36N38W SUPPORTING
OVERALL FAIR WEATHER CONDITIONS.

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

$$
HUFFMAN




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