000 AXNT20 KNHC 120949 TWDAT TROPICAL WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 805 AM EDT TUE MAY 12 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 0600 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 0930 UTC. ...SPECIAL FEATURES... ...GALE WARNING FOR SW CARIBBEAN... A GALE WARNING IS IN EFFECT ALONG THE COAST OF COLOMBIA FROM 10N TO 13.5N BETWEEN 70W AND 75W...DUE TO A TIGHT PRESSURE GRADIENT BETWEEN HIGH PRESSURE OVER THE WESTERN ATLC AND LOWER PRESSURE OVER NORTHERN COLOMBIA. SEAS WILL RANGE FROM 9 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 05N17W WHERE THE ITCZ BEGINS AND CONTINUES TO 05N30W TO 04N40W TO THE COAST OF SOUTH AMERICA NEAR 03N51W. WIDELY SCATTERED MODERATE CONVECTION IS WITHIN 150 NM OF THE ITCZ AXIS. ...DISCUSSION... GULF OF MEXICO... A COLD FRONT ACROSS TEXAS AND LOUISIANA SUPPORTS A PRE-FRONTAL TROUGH OVER THE NW GULF THAT EXTENDS FROM 29N91W TO 27N97W. NUMEROUS MODERATE TO STRONG CONVECTION IS NW OF A LINE FROM 29N92W TO 21N98W. WEAK SURFACE HIGH PRESSURE OF 1021 MB IS LOCATED OVER SOUTHERN ALABAMA...WITH A RIDGE AXIS EXTENDING FROM THE WESTERN ATLC OVER THE NORTHERN GULF. THE NEARBY HIGH CENTER SUPPORTS LIGHT WINDS OVER NE GULF. EAST TO SOUTHEAST WINDS OF 15 TO 20 KT DOMINATE THE REMAINDER OF THE GULF. IN THE UPPER LEVELS...AN UPPER LOW CENTERED JUST WEST OF THE CENTRAL BAHAMAS SUPPORTS ISOLATED SHOWERS FROM 24N TO 29N FROM THE FLORIDA PENINSULA TO 84W. THE CONVECTION ACROSS THE NORTHWESTERN GULF IS FORECAST TO PERSIST THROUGH TODAY WHILE GRADUALLY WEAKENING. THE UPPER LOW WILL SUPPORT ISOLATED TO SCATTERED THUNDERSTORMS OVER THE EASTERN GULF FOR THE NEXT 24 HOURS. CARIBBEAN SEA... A STRONG PRESSURE GRADIENT BETWEEN HIGH PRESSURE OVER THE CENTRAL ATLC AND LOW PRESSURE OVER COLOMBIA SUPPORTS GALE FORCE WINDS OVER THE SW CARIBBEAN. PLEASE SEE THE SPECIAL FEATURES SECTION FOR MORE DETAILS. ELSEWHERE...GENTLE TO MODERATE EASTERLY TRADE WINDS PREVAIL. AN UPPER LOW WEST OF THE BAHAMAS HAS A TROUGH AXIS THAT EXTENDS SOUTHWESTWARD TO NICARAGUA. SCATTERED THUNDERSTORMS ARE FROM 18N TO 23N BETWEEN 73W AND 80W. ISOLATED MODERATE CONVECTION IS SOUTH OF 11N ALONG THE COASTS OF PANAMA AND COSTA RICA. THIS CONVECTION IS SUPPORTED BY THE INTERACTION OF A SURFACE TROUGH OVER THE EASTERN PACIFIC AND THE BASE OF THE TROUGH AXIS OVER THE WESTERN CARIBBEAN. LITTLE CHANGE IS EXPECTED OVER THE NEXT 24 HOURS. ...HISPANIOLA... THE UPPER LEVEL TROUGH CURRENTLY ACROSS THE WESTERN CARIBBEAN IS SUPPORTING ISOLATED CONVECTION ACROSS THE ISLAND. EXPECT A SIMILAR PATTERN OVER THE NEXT 24 HOURS. ATLANTIC OCEAN... AN UPPER LOW CENTERED JUST WEST OF THE CENTRAL BAHAMAS SUPPORTS SCATTERED MODERATE CONVECTION FROM 22N TO 26N BETWEEN 76W AND 81W. ANOTHER UPPER LOW CENTERED NEAR 28N72W SUPPORTS ISOLATED THUNDERSTORMS FROM 24N TO 29N BETWEEN 61W AND 72W. A BROAD SURFACE RIDGE ANCHORED BY A 1029 MB SURFACE HIGH CENTERED NEAR 32N58W SUPPORTS ANTICYCLONIC FLOW OVER THE WESTERN AND CENTRAL SUBTROPICAL NORTHERN ATLC. FARTHER EAST...A COLD FRONT EXTENDS FROM 32N19W TO 24N24W TO 19N35W. NO CONVECTION IS NOTED WITH THIS FRONT. EXPECT CONVECTION TO CONTINUE OVER THE BAHAMAS TODAY. A COLD FRONT WILL EMERGE OFF THE SOUTHEASTERN US COAST LATE TONIGHT WITH CONVECTION. FOR ADDITIONAL INFORMATION PLEASE VISIT HTTP://WWW.HURRICANES.GOV/MARINE $$ LATTO