000
AXNT20 KNHC 081718
TWDAT 

TROPICAL WEATHER DISCUSSION
NWS NATIONAL HURRICANE CENTER MIAMI FL
105 PM EST THU MAR 08 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
1500 UTC.

...ITCZ/MONSOON TROUGH...

THE MONSOON TROUGH EXTENDS ACROSS W AFRICA TO THE COAST OF NRN 
LIBERIA AT 6.5N11W TO 3N15W. THE ITCZ CONTINUES FROM 3N15W TO 
THE COAST OF BRAZIL AT 1S46W. SCATTERED MODERATE/ISOLATED STRONG 
CONVECTION IS FROM 1N-5N BETWEEN 22W-47W. 

...DISCUSSION...

GULF OF MEXICO...
UPPER LEVEL RIDGING PREVAILS OVER THE GULF OF MEXICO WITH THE 
AXIS OF THE RIDGE EXTENDING FROM THE E PACIFIC ACROSS THE BAY OF 
CAMPECHE AND UP THE ERN SEABOARD. A SURFACE RIDGE EXTENDS JUST N 
OF THE AREA EXTENDING FROM A 1039 MB HIGH PRESSURE CENTER NEAR 
37N57W. THE PRESSURE GRADIENT BETWEEN THIS SURFACE RIDGE AND 
LOWER PRESSURE ALONG THE TROPICAL BELT IN THE E PACIFIC IS 
MAINTAINING FRESH TO STRONG E TO SE WINDS ACROSS THE GULF 
WATERS. WITH HIGH PRESSURE PREVAILING ACROSS THE GULF 
WATERS...DRY AND STABLE CONDITIONS PREVAIL. ONLY A FEW LOW 
TOPPED SHOWERS ARE FOUND ACROSS THE SE GULF RESULTING FROM 
SHOWERS STREAMING OFF THE NW COAST OF CUBA. THE SURFACE RIDGE 
WILL WEAKEN AND RETREAT EASTWARD THROUGH THE OVERNIGHT HOURS 
ENABLING A COLD FRONT TO MOVE OFF THE TEXAS COAST FRI MORNING. 

CARIBBEAN SEA...
AN UPPER LEVEL TROUGH PREVAILS ACROSS THE CARIBBEAN WATERS WITH 
TROUGH AXIS EXTENDING ACROSS THE WINDWARD PASSAGE TO PANAMA. A 
DRY AIRMASS PREVAILS ACROSS THE AREA AS DEPICTED BY THE LATEST 
SATELLITE DERIVED TPW PRODUCT. THIS IS INHIBITING DEEP 
CONVECTION WITH ONLY ISOLATED TRADEWIND SHOWERS MAINLY OVER THE 
NORTHERN HALF OF THE CARIBBEAN WATERS. TRADEWIND FLOW OF 20-25 
KTS PREVAILS ACROSS MUCH OF THE AREA REACHING GALE FORCE OFF  
THE COAST OF COLOMBIA. WITH LITTLE CHANGE TO THE LARGE SCALE 
SYNOPTIC PATTERN...EXPECT THESE CONDITIONS TO PREVAIL OVER THE 
NEXT 24 HOURS.

ATLANTIC OCEAN...
AN UPPER LEVEL TROUGH EXTENDS ACROSS THE SW N ATLC WATERS. A 
SHEARLINE EXTENDS ACROSS THE AREA FROM 31N39W TO THE CENTRAL 
BAHAMAS. SPEED CONVERGENCE INTO THE SHEARLINE COMBINED WITH 
UPPER LEVEL DIFFLUENCE E OF THE THE UPPER TROUGH AXIS IS 
ENHANCING CONVECTION FROM 24N TO 28N BETWEEN 57W AND 64W. FRESH 
TO STRONG TRADEWINDS ARE FOUND N OF THE SHEARLINE AXIS...AND 
FRESH TRADEWINDS ARE FOUND S OF THE SHEARLINE AXIS. THE 
SHEARLINE AXIS IS EXPECTED TO WEAKEN AND DISSIPATE OVER THE 
NEXT 24 HOURS. OVER THE CENTRAL ATLANTIC...A WEAKENING UPPER 
LEVEL TROUGH...THE REMNANT TROUGH OF THE UPPER LEVEL LOW FROM 
YESTERDAY EXTENDS N OF 15N ALONG 40W. THIS FEATURE MAINTAINING A 
WEAKENING SURFACE TROUGH FROM 31N35W TO 24N36W. THERE ARE NO 
ASSOCIATED SHOWERS NEAR THE SURFACE TROUGH AXIS. THE UPPER LEVEL 
TROUGH WILL CONTINUE SHIFTING EASTWARD OVER THE NEXT 24 
HOURS...AND THE SURFACE TROUGH WILL DISSIPATE. OVER THE EASTERN 
ATLANTIC...AN UPPER LEVEL RIDGE IS PRODUCING STABLE CONDITIONS 
AND LIMITED SHOWER ACTIVITY. SW WIND FLOW BETWEEN THE UPPER 
LEVEL RIDGE AND UPPER LEVEL TROUGH MENTIONED ABOVE IS ADVECTING 
UPPER LEVEL MOISTURE FROM NORTHERN BRAZIL TO W AFRICA. 

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

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