000
AXNT20 KNHC 251117
TWDAT 

TROPICAL WEATHER DISCUSSION
NWS NATIONAL HURRICANE CENTER MIAMI FL
705 AM EST SUN DEC 25 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 0600 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 
1115 UTC.

...ITCZ/MONSOON TROUGH...

THE INTERTROPICAL CONVERGENCE ZONE AXIS EXTENDS FROM 07N13W TO 
04N20W TO 03N30W TO 06N45W TO 05N53W. ISOLATED MODERATE 
CONVECTION IS FROM 03N-08N BETWEEN 24W-34W. A SURFACE TROUGH IS 
ANALYZED N OF THE WESTERN EXTENT OF THE ITCZ AXIS FROM 18N41W TO 
08N46W LARGELY A REFLECTION OF AN UPPER LEVEL LOW CENTERED 
NEAR 20N45W. LOW-LEVEL CONVERGENCE EAST OF THE SURFACE TROUGH 
AND STRONG UPPER LEVEL DIFFLUENCE EAST OF THE UPPER LEVEL LOW IS 
GENERATING A LARGE AREA OF WIDELY SCATTERED MODERATE CONVECTION 
NORTH OF THE ITCZ FROM 11N-18N BETWEEN 30W-40W.

...DISCUSSION...

GULF OF MEXICO...
A 1018 MB LOW IS CENTERED OVER THE NW GULF OF MEXICO NEAR 
28N95W. A WARM FROM EXTENDS E FROM THE LOW TO THE CENTRAL GULF 
NEAR 29N88W. A STATIONARY FRONT EXTENDS S FROM THE LOW TO THE 
BAY OF CAMPECHE NEAR 18N94W. ISOLATED MODERATE CONVECTION IS 
WITHIN 30 NM OF THE FRONTS. NORTHERLY GALE FORCE WINDS ARE OVER 
THE FAR WESTERN GULF FROM 21N-25N W OF FRONT. 15-20 KT EASTERLY 
WINDS AND MOSTLY FAIR WEATHER ARE OVER THE WARM SECTION E OF THE 
STATIONARY FRONT AND S OF THE WARM FRONT. EXPECT THE FRONTAL 
SYSTEMS TO BECOME STATIONARY OVER THE NEXT 24 HOURS WITH 
CONVECTION. ALSO EXPECT THE GALE TO WEAKEN TO 30 KT IN 18 HOURS. 

CARIBBEAN SEA...
A TIGHT SURFACE PRESSURE GRADIENT REMAINS OVER THE CARIBBEAN 
SEA. 15-30 KT TRADEWINDS ARE OVER THE CARIBBEAN SEA WITH 
STRONGEST WINDS ALONG THE COAST OF N COLOMBIA. A MONSOON TROUGH 
EXTENDS FROM N COLOMBIA TO COSTA RICA. ISOLATED MODERATE 
CONVECTION IS ALONG THE COAST OF PANAMA. SCATTERED SHOWERS ARE 
OVER NICARAGUA...HONDURAS...GUATEMALA...BELIZE...AND THE GULF OF 
HONDURAS MOVING W. PATCHES OF BROKEN TO OVERCAST LOW CLOUDS WITH 
ISOLATED SHOWERS DOTS THE E CARIBBEAN E OF 72W. EXPECT OVER THE 
NEXT 24 HOURS FOR MORE SHOWERS TO ADVECT TO THE SW CARIBBEAN AND 
CENTRAL AMERICA. 

ATLANTIC OCEAN...
A COLD FRONT IS OVER THE W ATLANTIC FROM 32N60W TO 29N72W. 
SCATTERED SHOWERS ARE WITHIN 60 NM OF THE FRONT. A SURFACE 
TROUGH IS OVER THE CENTRAL ATLANTIC FROM 35N44W TO 24N47W. 
SCATTERED SHOWERS ARE WITHIN 30 NM OF THE TROUGH. AN UPPER LEVEL 
LOW IS CENTERED NEARBY AT 25N43W PRODUCING ISOLATED MODERATE 
CONVECTION FROM 20N-28N BETWEEN 35W-40W. A 1036 MB HIGH IS 
CENTERED W OF SPAIN AT 41N20W. A RIDGE AXIS EXTENDS S FROM THE 
HIGH TO 20N32W. EXPECT OVER THE NEXT 24 HOURS FOR THE FRONTAL 
SYSTEM TO MOVE E WITH SHOWERS WHILE THE CENTRAL ATLANTIC TROUGH 
REMAINS QUASI-STATIONARY. 

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

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FORMOSA