Tropical Weather Discussion
Issued by NWS

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000
AXNT20 KNHC 210002
TWDAT

TROPICAL WEATHER DISCUSSION
NWS NATIONAL HURRICANE CENTER MIAMI FL
705 PM EST SAT DEC 20 2014

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 1800 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH
2315 UTC.

...SPECIAL FEATURE...

A 1009 MB SURFACE LOW CENTERED NEAR 31N45W IS GENERATING GALE
FORCE WINDS ACROSS THE CENTRAL ATLANTIC PARTICULARLY WITHIN 210
NM SE QUADRANT OF THE LOW CENTER. THIS SYSTEM IS GENERATING SEAS
UP TO 17 FT IN THE AREA OF STRONGEST WINDS. THE LOW IS FORECAST
TO MOVE JUST N OF THE AREA WITHIN THE NEXT 06 HOURS. AS A
RESULT..THE GALE WARNING IS IN EFFECT UNTIL 21/0000 UTC.

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

THE MONSOON TROUGH CROSSES THE COAST OF AFRICA NEAR 10N14W TO
10N17W WHERE THE ITCZ BEGINS AND CONTINUES TO 06N20W TO 05N30W
TO THE COAST OF SOUTH AMERICA AT 01N50W. ISOLATED MODERATE
CONVECTION IS FROM 4N-8N BETWEEN 20W-29W...FROM 3N-5N BETWEEN
36W-40W...AND FROM 1N-7N BETWEEN 42W-48W.

...DISCUSSION...

GULF OF MEXICO...

AS OF 2100 UTC...A WEAK 1015 MB LOW IS CENTERED OVER THE NE GULF
OF MEXICO NEAR 29N87W. A QUASI-STATIONARY FRONT EXTENDS ENE FROM
THE LOW TO BEYOND ST AUGUSTINE FLORIDA AT 30N81W. A COLD FRONT
EXTENDS SW FROM THE LOW TO 24N94W TO THE BAY OF CAMPECHE AT
20N96W. RADAR IMAGERY SHOWS SCATTERED SHOWERS OVER THE NE GULF
AND N FLORIDA N OF 29N E OF 87W. 15-20 KT WINDS ARE IN THE
VICINITY OF THE LOW AND N OF FRONT. MOSTLY 10 KT WINDS ARE S OF
FRONT. A SURFACE TROUGH IS OVER THE SE GULF AND THE YUCATAN
PENINSULA FROM 24N86W TO BEYOND 20N88W. SCATTERED MODERATE
CONVECTION IS OVER THE YUCATAN CHANNEL FROM 19N-23N BETWEEN 84W-
88W. IN THE UPPER LEVELS...A BROAD RIDGE IS PRODUCING WSW FLOW
OVER THE GULF. UPPER LEVEL MOISTURE IS OVER MOST OF THE GULF.
EXPECT OVER THE NEXT 24 HOURS FOR THE SURFACE LOW TO MOVE TO THE
ATLANTIC OFF THE GEORGIA COAST...WHILE THE TAIL END OF THE FRONT
DRIFTS BACK NORTH TOWARD TAMPICO MEXICO. ALSO EXPECT THE SURFACE
TROUGH TO REMAIN QUASI-STATIONARY OVER THE SE GULF WITH
CONVECTION.

CARIBBEAN SEA...

A SURFACE TROUGH EXTENDS FROM THE SE GULF TO THE COAST OF BELIZE
FROM 24N86W TO 20N88W TO 17N88W. CONVECTION IS MOSTLY N OF 19N
BETWEEN 84W-88W. 10-25 KT TRADEWINDS ARE OVER THE CARIBBEAN SEA
WITH STRONGEST WINDS ALONG THE COAST OF N COLOMBIA. RADAR
IMAGERY SHOWS ISOLATED SHOWERS OVER PUERTO RICO. SIMILAR SHOWERS
ARE OVER THE LEEWARD ISLANDS N OF 14N E OF 70W. IN THE UPPER
LEVELS...A BROAD RIDGE IS PRODUCING WSW FLOW OVER THE CARIBBEAN.
EXPECT OVER THE NEXT 24 HOURS FOR THE SOUTHERN PORTION OF THE
SURFACE TROUGH TO DRIFT W OVER THE YUCATAN PENINSULA WITH
CONTINUED CONVECTION. ALSO EXPECT MORE SHOWERS OVER THE NE
CARIBBEAN...AND THE SW CARIBBEAN ALONG THE COAST OF PANAMA.

HISPANIOLA...

FAIR WEATHER PREVAILS OVER THE ISLAND AS A BROAD UPPER-LEVEL
RIDGE WITH STRONG SUBSIDENCE PERSISTS. SIMILAR CONDITIONS ARE
EXPECTED OVER THE NEXT 24 HOURS WITH SCATTERED SHOWERS S OF THE
ISLAND.

ATLANTIC OCEAN...

AS OF 2100 UTC...A COLD FRONT IS OVER THE CENTRAL ATLANTIC FROM
31N55W TO 30N63W. A QUASI-STATIONARY FRONT CONTINUES W TO 30N73W
TO 31N78W TO ST AUGUSTINE FLORIDA AT 30N81W. SCATTERED SHOWERS
ARE WITHIN 30 NM OF THE FRONT. A 1019 MB HIGH IS FURTHER S NEAR
26N65W. A 1009 MB GALE LOW IS CENTERED NEAR 31N45W. SEE ABOVE. A
COLD FRONT EXTENDS S FROM THE LOW TO 28N42W TO 22N41W. WIDELY
SCATTERED MODERATE CONVECTION IS WITHIN 120NM E OF FRONT. A
LARGE 1038 MB HIGH IS OVER THE E ATLANTIC CENTERED NEAR 40N22W
WITH SURFACE RIDGING EXTENDING S OF THE CANARY ISLANDS. OF NOTE
IN THE UPPER LEVELS...AN UPPER LEVEL TROUGH IS ABOVE THE GALE
LOW. ALSO A SMALL UPPER LEVEL LOW IS CENTERED ABOVE THE CANARY
ISLANDS. EXPECT OVER THE NEXT 24 HOURS FOR THE COLD FRONT TO
DRIFT ESE WITH SHOWERS. ALSO EXPECT THE GALE LOW TO MOVE TO
38N40W WITH A COLD FRONT EXTENDING S TO 27N42W WITH CONVECTION.

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

$$
FORMOSA


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