[Tropical] Tropical Weather Discussion

[EMWIN Server]

AXNT20 KNHC 260005
TWDAT

TROPICAL WEATHER DISCUSSION
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
705 PM EST FRI DEC 25 2009

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...METEOROLOGICAL ANALYSIS...WEATHER
OBSERVATIONS...AND RADAR.

BASED ON 1800 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY
THROUGH 2315 UTC.

...THE ITCZ...

FROM 8N13W AT THE SIERRA LEONE COAST TO 4N30W TO 4N39W...INTO
NORTHEASTERN BRAZIL AT 51W ALONG THE EQUATOR. ISOLATED MODERATE
SHOWERS FROM 2N TO 3N BETWEEN 45W AND COASTAL FRENCH GUIANA.
SHOWERS ARE POSSIBLE ELSEWHERE TO THE SOUTH OF 6N.

...DISCUSSION...

THE GULF OF MEXICO AND THE NORTHWESTERN CARIBBEAN SEA...
THE VIGOROUS DEEP LAYER TROUGH OF 24 HOURS AGO...WHOSE CYCLONIC
FLOW COVERED PARTS OF OKLAHOMA...TEXAS...ARKANSAS...LOUISIANA...
AND THE NORTHWESTERN GULF OF MEXICO...HAS MOVED NORTHWARD INTO
THE UPPER MIDWEST OF THE U.S.A. AN UPPER LEVEL JET STREAM WITH
WINDS FROM THE WEST AND SOUTHWEST...MOVES FROM THE EASTERN
PACIFIC OCEAN ACROSS MEXICO...TOWARD FLORIDA AND BEYOND...ALONG
THE U.S.A. EAST COAST. THIS TROUGH LEAVES BEHIND A COLD FRONT
THAT MUST BE COMPARATIVELY MORE SHALLOW THAN IT WAS 24 HOURS
AGO. THE FRONT HAS LOST MUCH OF THE UPPER LEVEL SUPPORT THAT
IT USED TO HAVE. THE FRONT PASSES THROUGH EXTREME NORTHEASTERN
FLORIDA TO THE FLORIDA WEST COAST TO THE WEST OF LAKE
OKEECHOBEE...ACROSS WESTERN CUBA...INTO THE NORTHWESTERN
CARIBBEAN SEA TO THE CENTRAL COAST OF HONDURAS. BROKEN TO
OVERCAST LOW LEVEL TO MIDDLE LEVEL CLOUDS AND POSSIBLE
PRECIPITATION ARE WITHIN 30 NM TO 45 NM ON EITHER SIDE OF THE
LINE THAT RUNS FROM JUST TO THE EAST OF LAKE OKEECHOBEE TO
KEY WEST FLORIDA...TO CUBA NEAR 23N83W TO 19N85W IN THE
NORTHWESTERN CARIBBEAN SEA. SURFACE HIGH PRESSURE HAS
DEVELOPED IN THE GULF OF MEXICO TO THE WEST OF THE COLD FRONT.

THE REST OF THE CARIBBEAN SEA...
LOW LEVEL CYCLONIC FLOW ORIGINATES NEAR 19N63W ACCORDING TO THE
LAST VISIBLE SATELLITE IMAGES OF THE DAY. A TROUGH EXTENDS FROM
THE AREA OF CYCLONIC FLOW...ACROSS THE NORTHEASTERN CARIBBEAN
SEA ISLANDS TO 17N65W...TO A THIN LINE OF CLOUDS ALONG 17N67W
AND 16N70W. ISOLATED MODERATE SHOWERS ARE WITHIN 30 NM ON EITHER
SIDE OF 16N BETWEEN 64W AND 68W. BROKEN TO OVERCAST MULTILAYERED
CONVECTIVE DEBRIS CLOUDS FROM ALREADY-DISSIPATED
PRECIPITATION...COVER THE AREA FROM 17N TO 21N BETWEEN 60W AND
64W. OTHER POSSIBLE SHOWERS ARE A BIT TO THE NORTHEAST IN THE
ATLANTIC OCEAN FROM 19N TO 21N BETWEEN 58W AND 60W. THE MIDDLE
LEVEL TO UPPER LEVEL TROUGH FROM 24 HOURS AGO NOW PASSES OVER
HISPANIOLA 14N77W AND STILL NEAR THE PANAMA/COSTA RICA BORDER.

THE ATLANTIC OCEAN...
A CENTRAL ATLANTIC OCEAN TROUGH THAT PASSES THROUGH 33N47W TO
27N48W TO 24N60W SUPPORTS THE CURRENT COLD FRONT THAT IS ALONG
32N45W TO 25N50W TO 22N57W. THE FRONT IS STATIONARY FROM 22N57W
TO 21N65W AND 21N71W. BROKEN TO OVERCAST MULTILAYERED CLOUDS AND
POSSIBLE PRECIPITATION ARE WITHIN AT LEAST 240 NM TO THE EAST
AND SOUTHEAST OF THE FRONT. SURFACE HIGH PRESSURE COVERS THE
AREA TO THE EAST OF THE FRONT...FROM 10N TO 30N BETWEEN AFRICA
AND 40W...AROUND A 1016 MB HIGH PRESSURE CENTER THAT IS NEAR
21N34W. SURFACE HIGH PRESSURE IS TO THE WEST AND NORTHWEST OF
THE 32N45W 21N71W FRONT...AROUND A 67W/68W RIDGE...TO THE NORTH
OF 23N.

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

$$
MT





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