[Tropical] Tropical Weather Discussion

[EMWIN Server]

AXNT20 KNHC 161742
TWDAT

TROPICAL WEATHER DISCUSSION
NWS NATIONAL HURRICANE CENTER MIAMI FL
105 PM EST FRI DEC 16 2011

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.

...THE ITCZ/THE MONSOON TROUGH...

THE ITCZ PASSES THROUGH THE COASTAL BORDER OF WESTERN LIBERIA
AND SOUTHERN SIERRA LEONE NEAR 7N11W TO 8N17W 6N30W 5N36W
7N50W. ISOLATED AND MODERATE RAINSHOWERS ARE FROM 3N TO 7N
BETWEEN 23W AND 38W.

...DISCUSSION...

THE GULF OF MEXICO...
A MIDDLE LEVEL TO UPPER LEVEL TROUGH IS ORGANIZING ITSELF IN
THE CENTRAL U.S.A. THIS FEATURE SUPPORTS A COLD FRONT THAT HAS
REACHED THE TEXAS GULF COAST WATERS. THE FRONT PASSES THROUGH
SOUTHWESTERN LOUISIANA AND THE UPPER TEXAS GULF COAST TO THE
COAST OF THE DEEP SOUTH OF TEXAS...INTO MEXICO NEAR 24N100W AND
25N103W. RAINSHOWERS ARE POSSIBLE TO THE NORTHWEST OF THE LINE
THAT PASSES THROUGH 29N91W AND BEYOND 25N97W. UPPER LEVEL
ANTICYCLONIC WIND FLOW COVERS THE ENTIRE AREA. A SURFACE RIDGE
PASSES THROUGH THE NORTHEASTERN CORNER OF THE GULF OF MEXICO...
INTO THE CENTRAL GULF WATERS...TO THE SOUTHWESTERN CORNER OF
THE AREA.

THE CARIBBEAN SEA...

LARGE-SCALE UPPER LEVEL ANTICYCLONIC WIND FLOW IS ASSOCIATED
WITH A RIDGE THAT EXTENDS FROM CENTRAL VENEZUELA...THROUGH
THE SOUTH CENTRAL CARIBBEAN SEA...INTO THE NORTHWESTERN CORNER
OF THE AREA. THE MONSOON TROUGH IS ALONG 12N74W IN THE COASTAL
WATERS OF NORTHERN COLOMBIA TO 9N78W IN EASTERN PANAMA...ACROSS
COASTAL PANAMA INTO COSTA RICA NEAR 10N85W...AND BEYOND
NORTHWESTERN COSTA RICA INTO THE EASTERN PACIFIC OCEAN.
SCATTERED MODERATE TO ISOLATED STRONG RAINSHOWERS ARE TO THE
SOUTH OF 13N BETWEEN 76W AND THE COAST OF CENTRAL AMERICA.
AN ATLANTIC OCEAN COLD FRONT PASSES THROUGH TO 15N61W IN
NORTHERN COASTAL MARTINIQUE. A SHEAR AXIS CONTINUES FROM
15N61W TO 14N66W 13N72W 12N76W. RAINSHOWERS ARE POSSIBLE WITHIN
30 TO 45 NM ON EITHER SIDE OF 15N60W 14N63W 13N66W...AND WITHIN
60 NM ON EITHER SIDE OF 13N66W 13N74W 12N79W. THE AREAS OF THE
MONSOON TROUGH APPEAR TO OVERLAP WITH THE SHEAR AXIS.
RAINSHOWERS ARE POSSIBLE ALSO WITHIN 30 NM ON EITHER SIDE OF
18N74W 16N79W 15N83W...FROM THE SOUTHWESTERN COAST OF HAITI
TOWARD THE COASTAL BORDERS OF NORTHEASTERN NICARAGUA AND EASTERN
HONDURAS.

THE ATLANTIC OCEAN...

UPPER LEVEL ANTICYCLONIC WIND FLOW COVERS THE ATLANTIC OCEAN TO
THE WEST OF 65W. MIDDLE LEVEL TO UPPER LEVEL CYCLONIC FLOW COVER
THE CENTRAL ATLANTIC OCEAN TO THE NORTH OF 10N BETWEEN 45W AND
65W. THE CYCLONIC FLOW IS DUE TO A 25N53W CYCLONIC CIRCULATION
CENTER AND A TROUGH. THE AREA OF CYCLONIC FLOW SUPPORTS A COLD
FRONT THAT PASSES THROUGH 32N48W TO A 1007 MB LOW PRESSURE
CENTER THAT IS NEAR 25N51W...TO 20N52W...AND TO 15N61W IN
NORTHERN COASTAL MARTINIQUE OF THE EASTERN CARIBBEAN SEA
ISLANDS. A SURFACE TROUGH CURVES ALONG 25N47W 20N47W 12N50W
7N56W. ISOLATED MODERATE TO LOCALLY STRONG RAINSHOWERS ARE FROM
10N TO 20N BETWEEN 40W AND 50W. WIDELY SCATTERED TO SCATTERED
MODERATE AND ISOLATED STRONG RAINSHOWERS ARE FROM 20N BEYOND
32N BETWEEN 40W AND 55W. RAINSHOWERS ARE POSSIBLE WITHIN 60 NM
ON EITHER SIDE OF 21N49W 17N55W 15N61W. A MIDDLE LEVEL TO UPPER
LEVEL CYCLONIC CIRCULATION CENTER IS NEAR 20N28W. CYCLONIC WIND
FLOW COVERS THE AREA FROM 11N TO 31N BETWEEN AFRICA AND 34W.
NO SIGNIFICANT DEEP CONVECTIVE PRECIPITATION IS APPARENT SOLELY
FROM SATELLITE IMAGERY. A SURFACE RIDGE EXTENDS FROM A 1035 MB
HIGH PRESSURE CENTER THAT IS NEAR 34N24W...TO 28N30W 22N34W AND
TO 14N40W.

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

$$
MT





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