000 AXNT20 KNHC 072328 TWDAT TROPICAL WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 805 PM EDT TUE APR 07 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 2245 UTC. ...SPECIAL FEATURES... A GALE WARNING WILL GO INTO EFFECT TONIGHT FOR A FEW HOURS ALONG THE COASTAL WATERS OF COLOMBIA DUE TO THE STRONG PRESSURE GRADIENT BETWEEN THE LOWER PRESSURE ACROSS SOUTH AMERICA AND HIGH PRESSURE ANCHORED ACROSS THE W ATLC. PLEASE SEE LATEST NWS HIGH SEAS FORECAST UNDER AWIPS/WMO HEADERS MIAHSFAT2/FZNT02 KNHC FOR MORE DETAILS. ...ITCZ/MONSOON TROUGH... THE MONSOON TROUGH EXTENDS ACROSS AFRICA INTO THE TROPICAL ATLC NEAR 7N11W TO 3N13W WHERE THE ITCZ BEGINS AND CONTINUES ALONG 1N16W THEN S OF THE EQUATOR NEAR 19W. CLUSTERS OF SCATTERED MODERATE CONVECTION ARE FROM 2N-5N BETWEEN 13W-19W AND FROM 2N TO S OF THE EQUATOR BETWEEN 19W-23W. ...DISCUSSION... GULF OF MEXICO... A BROAD UPPER RIDGE EXTENDS OVER MEXICO AND THE FAR W GULF OF MEXICO ANCHORED IN THE E PACIFIC REGION. YET ANOTHER SHORTWAVE UPPER TROUGH IS MOVING ACROSS THE MISSISSIPPI VALLEY AGAIN THIS EVENING AND COUPLED WITH LINGERING LOW LEVEL MOISTURE ARE GENERATING SHOWERS/THUNDERSTORM ACTIVITY WELL N OF THE GULF WATERS. AFTERNOON SHOWERS/THUNDERSTORMS HAVE DEVELOPED INLAND OVER THE W COAST OF FLORIDA AND OVER THE FLORIDA PANHANDLE. A SURFACE RIDGE EXTENDS FROM THE W ATLC ACROSS THE N GULF COAST TO OVER CENTRAL TEXAS. THIS IS GIVING THE GULF MOSTLY CLEAR SKIES THIS EVENING. SURFACE RIDGE WILL CONTINUE TO MAINTAIN MODERATE E TO SE WINDS ACROSS THE AREA THROUGH FRI. CARIBBEAN SEA... NEAR ZONAL NW FLOW ALOFT COVERS THE CARIBBEAN THIS EVENING. SATELLITE WATER VAPOR IMAGERY CONTINUES TO INDICATE STRONG SUBSIDENCE AND THUS DRY STABLE AIR ACROSS ALL BUT THE FAR NW CARIBBEAN WHERE UPPER MOISTURE IS BEING ADVECTED INTO THE BASIN FROM THE GULF OF MEXICO. AFTERNOON SHOWERS AND POSSIBLE ISOLATED THUNDERSTORMS HAVE AGAIN DEVELOPED INLAND OVER PUERTO RICO... HISPANIOLA...JAMAICA...AND ALONG THE S COAST OF CUBA. E SURFACE WINDS ARE SHIFTING THE SHOWERS INTO THE CARIBBEAN WATERS AND THE MONA PASSAGE. EASTERLY TRADE WINDS ARE GENERATING ISOLATED SHOWERS ACROSS THE LESSER ANTILLES AND ARE BANKING SHOWERS INLAND AND WITHIN 60 NM ALONG THE COAST OF W PANAMA AND COSTA RICA S OF NICARAGUA AND W OF 81W. THIS IS LEAVING THE REMAINDER OF THE CARIBBEAN WITH FAIR WEATHER THIS EVENING. STRONG WINDS ALONG THE NW COAST OF COLOMBIA WILL BRIEFLY INCREASE TO MINIMAL GALE FORCE TONIGHT. FRESH TRADES ARE ELSEWHERE ACROSS THE CENTRAL CARIBBEAN AND WILL INCREASE TO STRONG TRADE WINDS BY MID WEEK. MODERATE TO FRESH TRADES EXPECTED ACROSS THE W AND E CARIBBEAN. HISPANIOLA... AFTERNOON SHOWERS AND POSSIBLE THUNDERSTORMS HAVE DEVELOPED ACROSS MOST OF THE ISLAND THIS EVENING. LOW LEVEL MOISTURE IS INCREASING AND IS ALREADY PRODUCING MORE WIDESPREAD SHOWERS. THIS SCENARIO WILL CONTINUE THROUGH FRI. ATLANTIC OCEAN... A SURFACE RIDGE COVERS MOST OF THE ATLC ANCHORED BY A 1035 MB HIGH NW OF THE AZORES AND EXTENDING A RIDGE AXIS SW ALONG 32N70W TO OVER THE N GULF OF MEXICO COASTAL STATES. A LINGERING UPPER TROUGH OVER THE CENTRAL ATLC IS SUPPORTING A SURFACE TROUGH THAT EXTENDS FROM 28N67W TO 22N67W. SCATTERED SHOWERS AND POSSIBLE ISOLATED THUNDERSTORMS ARE WITHIN 120 NM E OF THE SURFACE TROUGH. ANOTHER UPPER TROUGH EXTENDS OVER THE NE ATLC N OF 28N E OF 30W SUPPORTING A SURFACE TROUGH THAT ENTERS THE E ATLC NEAR 32N12W THEN JUST E OF THE CANARY ISLANDS ALONG 28N14W TO 23N26W. THE W ATLC SURFACE TROUGH WILL WEAKEN AS IT REACHES NEAR 71W EARLY ON WED THEN DISSIPATE AS IT APPROACHES THE BAHAMAS WED NIGHT. A SURFACE RIDGE WILL DEVELOP E AND W ALONG 31N ON THU EXTENDING FROM BERMUDA TO NE FLORIDA ON FRI. FOR ADDITIONAL INFORMATION PLEASE VISIT HTTP://WWW.HURRICANES.GOV/MARINE $$ PAW