[Tropical] Tropical Weather Discussion

[EMWIN Server]

AXNT20 KNHC 211103
TWDAT

TROPICAL WEATHER DISCUSSION
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
705 AM EST TUE DEC 21 2010

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 0600 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY
THROUGH 1015 UTC.

...SPECIAL FEATURE...

A 1009 MB LOW PRESSURE CENTER IS NEAR 12N57W...ABOUT 140 NM
TO THE EAST-SOUTHEAST OF BARBADOS. A SURFACE TROUGH EXTENDS
FROM 13N38W TO 13N50W...CURVING TO THE LOW CENTER...TO 8N60W
NEAR THE COASTS OF VENEZUELA AND NORTHERN GUYANA. RAINSHOWERS
ARE WITHIN A 30 NM RADIUS OF 12N58W. OTHER DISORGANIZED
ISOLATED TO WIDELY SCATTERED MODERATE RAINSHOWERS AND POSSIBLE
THUNDERSTORMS ARE FROM 10N TO 17N BETWEEN 48W AND 55W.
DISORGANIZED ISOLATED MODERATE RAINSHOWERS ARE ALSO FROM 10N
TO 16N BETWEEN 36W AND 47W. IT IS POSSIBLE THAT THIS SYSTEM
MAY BECOME A TROPICAL CYCLONE DURING THE NEXT 48 HOURS.
THIS SYSTEM WILL BRING LOCALLY HEAVY RAINFALL AND GUSTY WINDS
TO MUCH OF THE LESSER ANTILLES DURING THE NEXT DAY OR SO EVEN
IF IT NEVER DEVELOPS INTO A TROPICAL CYCLONE.

...THE ITCZ...

FROM THE LIBERIA COAST NEAR 5N9W TO 3N16W 3N26W 2N40W...TO THE
EQUATOR ALONG 50W NEAR NORTHEASTERN COASTAL BRAZIL. NUMEROUS
STRONG RAINSHOWERS AND THUNDERSTORMS ARE FROM 3N TO 6N BETWEEN
6W AND 16W...IN THE SOUTHWESTERN COASTAL WATERS OF THE IVORY
COAST AND IN THE LIBERIA COASTAL WATERS. DISORGANIZED ISOLATED
MODERATE RAINSHOWERS TO LOCALLY STRONG THUNDERSTORMS ARE
ELSEWHERE FROM 1S TO 6N BETWEEN 19W AND 28W...AND FROM 2S
TO 9N BETWEEN 38W AND 54W...INCLUDING THE COASTAL WATERS FROM
NORTHEASTERN BRAZIL TO NORTHEASTERN GUYANA. UPPER LEVEL
SOUTHWESTERLY WINDS ARE WITHIN ABOUT 500 NM TO THE SOUTHEAST
OF THE LINE THAT GOES FROM 15N34W TO 24N20W BEYOND 25N14W
ACROSS THE WESTERN SAHARA.

...DISCUSSION...

THE GULF OF MEXICO...

BROAD UPPER LEVEL ANTICYCLONIC FLOW SPANS THE AREA BETWEEN 80W
AND 113W IN THE EASTERN PACIFIC OCEAN. A SURFACE RIDGE EXTENDS
FROM A 1023 MB HIGH PRESSURE CENTER THAT IS NEAR 31N84W ALONG THE
FLORIDA/GEORGIA BORDER TO 26N89W TO COASTAL MEXICO NEAR 20N97W.

FROM THE ATLANTIC OCEAN TO THE WEST OF 50W...AND THEN INTO
THE CENTRAL CARIBBEAN SEA...

BROAD CYCLONIC FLOW ON WATER VAPOR IMAGERY THAT COVERS THE
ATLANTIC OCEAN BETWEEN 50W AND 80W IS ASSOCIATED WITH THE
LONGWAVE TROUGH THAT PASSES THROUGH 32N63W TO 26N64W TO 21N70W.
THE TROUGH SUPPORTS THE COLD FRONT THAT PASSES THROUGH 32N51W TO
23N56W...THROUGH 20N60W...OVER SAINT MAARTEN AND SAINT BARTHELEMY
TO THE SOUTH OF SAINT CROIX...TO 17N66W IN THE CARIBBEAN SEA.
A SURFACE TROUGH CURVES FROM 17N66W TO 15N70W TO COASTAL
VENEZUELA NEAR 12N70W. ISOLATED MODERATE RAINSHOWERS ARE WITHIN
30 NM TO 45 NM ON EITHER SIDE THE LINE THAT PASSES THROUGH
32N48W 25N52W 20N58W 17N63W 16N70W 12N70W. BROKEN LOW CLOUDS AND
POSSIBLE PRECIPITATION ARE IN CLOUDS THAT ARE WITHIN 30 NM TO
60 NM ON EITHER SIDE OF THE LINE FROM 20N63W...THROUGH THE MONA
PASSAGE...TO 17N69W 15N71W. GALE FORCE WINDS ARE TO THE NORTH OF
28N WITHIN 300 NM TO THE EAST OF THE FRONT...WITH SEA HEIGHTS
RANGING FROM 10 FEET TO 16 FEET. GALE FORCE WINDS ALSO ARE TO
THE NORTH OF 27N BETWEEN THE FRONT AND 70W...WITH SEA HEIGHTS
RANGING FROM 16 FEET TO 23 FEET.

THE REST OF THE CARIBBEAN SEA...

MIDDLE LEVEL TO UPPER LEVEL NORTHWESTERLY WIND FLOW IS MOVING
ACROSS THE NORTHWESTERN CORNER OF THE AREA. MIDDLE LEVEL
SOUTHWESTERLY WIND FLOW IS ABOUT 240 NM TO THE SOUTHEAST OF
THE LINE THAT GOES FROM EASTERN HONDURAS BEYOND HISPANIOLA.
NORTHERLY SURFACE-TO-LOW LEVEL WINDS COVER THE AREA THAT IS TO
THE WEST OF 70W. A SURFACE TROUGH IS ALONG 17N63W TO 15N65W TO
13N67W. RAINSHOWERS ARE POSSIBLE FROM 12N TO 16N BETWEEN 62W
AND 68W.

THE REST OF THE ATLANTIC OCEAN...

BROAD UPPER LEVEL CYCLONIC FLOW IS TO THE NORTH OF 22N TO THE
EAST OF 35W. THIS IS ASSOCIATED WITH A TROUGH THAT IS IN THE
AREA. A SURFACE TROUGH IS INLAND THROUGH CENTRAL MOROCCO TO
THE CENTRAL PART OF THE WESTERN SAHARA. SURFACE ANTICYCLONIC
WIND FLOW COVERS THE AREA TO THE NORTH OF 16N BETWEEN AFRICA
AND 50W. THE ANTICYCLONIC FLOW MOVES AROUND A RIDGE THAT GOES
FROM 22N18W TO 23N29W...TO A 1019 MB HIGH PRESSURE CENTER THAT
IS NEAR 25N36W...BEYOND 32N40W.

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

$$

MT




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