000
AXNT20 KNHC 201745
TWDAT 

TROPICAL WEATHER DISCUSSION
NWS NATIONAL HURRICANE CENTER MIAMI FL
105 PM EST FRI JAN 20 2012

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 MONSOON TROUGH REACHES COASTAL SIERRA LEONE NEAR 8N13W AND 
CONTINUES SW TO 4N19W. THE ITCZ CONTINUES FROM 4N19W TO 3N30W TO 
3N36W TO COASTAL BRAZIL NEAR EQ50W. SCATTERED MODERATE 
CONVECTION IS S OF THE MONSOON TROUGH ALONG THE COAST OF THE 
IVORY COAST FROM 2N-4N BETWEEN 3W-5W. WIDELY SCATTERED MODERATE 
CONVECTION IS ALONG THE ITCZ FROM 1N-5N BETWEEN 26W-38W. 

...DISCUSSION...

THE GULF OF MEXICO...
10-20 KT SOUTHERLY RETURN FLOW DOMINATES THE GULF OF MEXICO WITH 
STRONGEST WINDS OVER THE NW GULF WHERE THE SURFACE PRESSURE 
GRADIENT TIGHTENS UP. MOSTLY FAIR WEATHER PREVAILS WITH PLENTY 
OF WARM AIR ADVECTION. SURFACE TEMPERATURES OVER THE NORTHERN 
GULF STATES ARE IN THE 60'S AND 70'S. IN THE UPPER LEVELS... NW 
FLOW PREVAILS OVER THE GULF WITH UPPER LEVEL MOISTURE AND 
SCATTERED HIGH CLOUDS OVER THE W GULF W OF 88W AND N OF 21N. 
STRONG SUBSIDENCE IS OVER THE REMAINDER OF THE GULF. EXPECT A 
COLD FRONT TO JUST INLAND OVER TEXAS IN 24 HOURS.   

THE CARIBBEAN SEA...
15-25 KT TRADEWINDS ARE OVER THE CARIBBEAN SEA WITH STRONGEST 
WINDS ALONG THE COAST OF COLOMBIA AND LIGHTEST WINDS IN THE GULF 
OF HONDURAS. PATCHES OF BROKEN LOW CLOUDS WITH SCATTERED SHOWERS 
ARE OVER THE WINDWARD ISLANDS...ALONG THE COASTS OF COSTA RICA 
AND NICARAGUA...AND OVER THE THE GULF OF HONDURAS. MOSTLY FAIR 
SKIES ARE OVER THE REMAINDER OF THE CARIBBEAN. IN THE UPPER 
LEVELS... NW FLOW IS OVER THE W CARIBBEAN W OF 75W WHILE ZONAL 
FLOW IS OVER THE E CARIBBEAN. STRONG SUBSIDENCE COVERS THE 
ENTIRE AREA. EXPECT LITTLE CHANGE OVER THE NEXT 24 HOURS.     

THE ATLANTIC OCEAN...
A 1023 MB HIGH IS OVER THE W ATLANTIC NEAR 32N72W PRODUCING FAIR 
WEATHER. A COLD FRONT IS FURTHER E ALONG 30N61W 22N70W. 
SCATTERED SHOWERS ARE WITHIN 15 NM OF THE FRONT. A 1016 MB LOW 
IS OVER THE CENTRAL ATLANTIC NEAR 27N44W DRIFTING NW. A COLD 
FRONT EXTENDS S FROM THE LOW ALONG 24N42W 20N43W 15N48W. A WARM 
FRONT ALSO EXTENDS NE FROM THE LOW TO 31N41W. WIDELY SCATTERED 
MODERATE CONVECTION IS NE OF THE LOW FROM 24N-32N BETWEEN 
38W-44W. A 1041 MB HIGH IS OVER THE E ATLANTIC NEAR 42N15W. A 
RIDGE AXIS EXTEND S FROM THE HIGH TO THE CAPE VERDE ISLANDS. 
EXPECT THE W ATLANTIC FRONT TO MOVE E OVER THE NEXT 24 HOURS 
WHILE THE OTHER FRONT REMAINS QUASI-STATIONARY WITH 
CONVECTION.   

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

$$
FORMOSA