000 AXNT20 KNHC 112325 TWDAT TROPICAL WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 805 PM EDT MON MAY 11 2015 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 FEATURES... ...GALE WARNING FOR SW CARIBBEAN... A GALE WARNING IS IN EFFECT ALONG THE COAST OF COLOMBIA FROM 11N- 13N BETWEEN 72W-77W DUE TO A TIGHT PRESSURE GRADIENT BETWEEN HIGH PRESSURE OVER THE WESTERN ATLANTIC AND LOWER PRESSURE OVER NORTHERN COLOMBIA AND SOUTH AMERICA IN GENERAL. SEAS WILL RANGE FROM 13 TO 15 FT WITH THE STRONGEST WINDS. THESE CONDITIONS WILL PULSE DURING THE OVERNIGHT AND MORNING HOURS THROUGH WEDNESDAY NIGHT. PLEASE SEE THE HIGH SEAS FORECAST UNDER WMO/AWIPS HEADERS MIAHSFAT2/FZNT02 KNHC FOR MORE DETAILS. ...ITCZ/MONSOON TROUGH... THE MONSOON TROUGH EXTENDS ACROSS AFRICA REACHING THE TROPICAL ATLANTIC NEAR 10N14W TO 05N20W WHERE THE ITCZ BEGINS AND CONTINUES TO 05N36W TO THE COAST OF SOUTH AMERICA NEAR 02N50W. ISOLATED CONVECTION PREVAILS ALONG THE ITCZ AXIS. ...DISCUSSION... GULF OF MEXICO... A SQUALL LINE CONTINUES SUPPORTING SCATTERED MODERATE TO STRONG CONVECTION ACROSS SOUTHERN LOUISIANA AND MISSISSIPPI. THIS CONVECTION IS ALSO REACHING THE ADJACENT GULF WATERS MAINLY N OF 29N BETWEEN 88W-97W. LATEST SCATTEROMETER DATA DEPICTS A SURFACE TROUGH EXTENDING FROM THE SQUALL LINE INTO THE NE GULF FROM 30N94W TO 28N96W. THE REMAINDER OF THE AREA IS DOMINATED BY A BROAD HIGH PRESSURE CENTERED OVER THE ATLANTIC AND EXTENDING SW REACHING THE BASIN. TO THE E...SCATTERED MODERATE TO STRONG CONVECTION HAS DEVELOPED ACROSS THE SW PORTION OF THE FLORIDA PENINSULA THIS AFTERNOON AND MOVED W REACHING THE E GULF FROM 25N-27N AND E OF 83W. AT UPPER LEVELS...AN UPPER-LEVEL RIDGE PREVAILS ACROSS THE WESTERN HALF OF THE BASIN WITH SUBSIDENCE. TO THE E OF 88W...AN UPPER-LEVEL TROUGH COVERS THE E GULF AND THE W CARIBBEAN SUPPORTING THE CONVECTION PREVIOUSLY MENTIONED. A LIGHT TO GENTLE ANTICYCLONIC FLOW PREVAILS ACROSS THE AREA. EXPECT OVER THE NEXT 24 HOURS FOR CONVECTION TO PREVAIL ACROSS THE E GULF. THE FRONTAL BOUNDARY CURRENTLY OVER TEXAS WILL REMAIN INLAND BUT SCATTERED MODERATE CONVECTION MAINLY ACROSS THE NW PORTION OF THE BASIN IS STILL EXPECTED DUE TO THE ONSHORE FLOW. CARIBBEAN SEA... A GALE WARNING IS IN EFFECT FOR THE WATERS NORTH OF COLOMBIA. PLEASE REFER TO THE SPECIAL FEATURES SECTION ABOVE FOR MORE DETAILS. A GENTLE TO MODERATE EASTERLY FLOW PREVAILS ACROSS THE REMAINDER OF THE BASIN. AN UPPER-LEVEL TROUGH EXTENDS ACROSS THE W CARIBBEAN SUPPORTING CONVECTION ACROSS CUBA...JAMAICA...AND THEIR ADJACENT WATERS. ANOTHER AREA OF SCATTERED MODERATE CONVECTION IS OVER THE ADJACENT WATERS N OF PANAMA...S OF 11N BETWEEN 81W-83W. THE UPPER-LEVEL NE FLOW ACROSS THE CENTRAL AND E CARIBBEAN CONTINUES TO BRING UPPER-LEVEL MOISTURE TO THE AREA. A STRONG SUBSIDENCE PREVAILS ELSEWHERE SUPPORTING FAIR WEATHER. EXPECT A SIMILAR PATTERN TO PREVAIL OVER THE NEXT 24-48 HOURS. ...HISPANIOLA... THE UPPER LEVEL TROUGH CURRENTLY ACROSS THE W CARIBBEAN IS SUPPORTING ISOLATED CONVECTION AND CLOUDINESS ACROSS THE ISLAND. EXPECT A SIMILAR PATTERN OVER THE NEXT 24 HOURS. ATLANTIC OCEAN... A BROAD 1030 MB SURFACE HIGH IS CENTERED NEAR 32N54W AND EXTENDING ACROSS MOST OF THE TROPICAL ATLANTIC WITH FAIR WEATHER. THE ONLY AREA WITH SOME CONVECTION IS E OF 30W...WHERE A 1002 MB LOW PRESSURE EXTENDS ITS COLD FRONT ACROSS OUR AREA FROM 31N23W TO 21N39W. ISOLATED CONVECTION IS OBSERVED ALONG THIS BOUNDARY. AT UPPER LEVELS...AN UPPER-LEVEL TROUGH IS OVER THE W ATLANTIC W OF 70W SUPPORTING CONVECTION ACROSS THE BAHAMAS AND THE ADJACENT WATERS N OF CUBA. EXPECT OVER THE NEXT 24 HOURS FOR THE COLD FRONT TO APPROACH THE CANARY ISLANDS WITH CONVECTION. FOR ADDITIONAL INFORMATION PLEASE VISIT HTTP://WWW.HURRICANES.GOV/MARINE $$ ERA