000 AXNT20 KNHC 101751 TWDAT TROPICAL WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 205 PM EDT SUN MAY 10 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 1200 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 1715 UTC. ...GALE WARNING FOR SW CARIBBEAN... A GALE WARNING HAS BEEN ISSUED FOR THE SW CARIBBEAN OFF THE COAST OF COLOMBIA. AS HIGH PRES BUILDS N OF AREA...WINDS ARE FORECAST TO PULSE TO MINIMAL GALE FORCE DURING THE OVERNIGHT AND EARLY MORNING HOURS THROUGH WED NIGHT. THE MOST RECENT HIGH RESOLUTION SCATTEROMETER PASS SHOWED GALE FORCE WINDS NEAR THE COAST OF COLOMBIA...PARTICULARLY FROM 11N TO 13N BETWEEN 72W AND 75W. SEAS ARE FORECAST TO BUILD TO 12-15 FT WITH THE STRONGEST WINDS. ...ITCZ/MONSOON TROUGH... THE MONSOON TROUGH EXTENDS ACROSS AFRICA...THEN ALONG THE COAST FROM SENEGAL TO GUINEA-BISSAU TO 10N16W TO 8N18W TO 6N23W WHERE THE ITCZ BEGINS AND CONTINUES FROM 6N23W TO 5N40W TO INLAND OVER SOUTH AMERICA NEAR 2N50W. SCATTERED MODERATE/ISOLATED STRONG CONVECTION IS FROM 4N-6.5N BETWEEN 11W-15W. SCATTERED MODERATE CONVECTION IS NOTED WITHIN 60 NM N OF THE ITCZ AXIS BETWEEN 28W- 37W AND BETWEEN 40W-43W. ...DISCUSSION... GULF OF MEXICO... A 1021 MB HIGH PRES IS CENTERED OVER THE NE GULF WITH A RIDGE EXTENDING ACROSS MOST OF THE GULF REGION. MOSTLY FAIR WEATHER PREVAILS ACROSS THE GULF UNDER THE INFLUENCE OF THIS SYSTEM. THE PRES GRADIENT BETWEEN THE RIDGE AND LOWER PRES OVER NE MEXICO WILL PRODUCE MODERATE TO FRESH SOUTHERLY RETURN FLOW ACROSS THE WESTERN HALF OF BASIN. A TROUGH IS ANALYZED ON THE 1200 UTC MAP OVER THE SW GULF AND EXTENDS FROM 22N85W TO 19N94W. THIS WEATHER PATTERN IS FORECAST TO PERSIST OVER THE NEXT SEVERAL DAYS. A SURFACE TROUGH WILL DEVELOP EACH AFTERNOON ACROSS THE YUCATAN PENINSULA AND SHIFT W-NW ACROSS THE SW GULF DURING THE EVENING AND OVERNIGHT HOURS...RESULTING IN ENHANCED WINDS AND SEAS. ALOFT...UPPER RIDGE ANCHORED IN THE E PACIFIC REGION EXTENDS A RIDGE AXIS ACROSS THE GULF OF MEXICO TO OVER THE SE CONUS NEAR PANAMA CITY FLORIDA WHILE AN UPPER TROUGH IN THE W ATLC COVERS THE FLORIDA PENINSULA. CARIBBEAN SEA... TRADE WINDS ARE EXPECTED TO INCREASE TO GALE FORCE ALONG THE COAST OF COLOMBIA DURING THE OVERNIGHT HOURS...TONIGHT THROUGH WED NIGHT. PLEASE SEE SPECIAL FEATURE FOR MORE DETAILS. ELSEWHERE...FRESH TO STRONG TRADES WILL PREVAIL ACROSS MUCH OF THE CARIBBEAN TODAY...THEN EXPAND WESTWARD TO THE GULF OF HONDURAS TONIGHT THROUGH WED AS STRONG HIGH PRES BUILDS N OF AREA. SHALLOW MOISTURE EMBEDDED IN THE TRADE WIND FLOW WILL CONTINUE TO MOVE ACROSS THE REGION PRODUCING ISOLATED TO SCATTERED PASSING SHOWERS. PATCHES OF MOISTURE FROM THE ATLANTIC ARE CURRENTLY MOVING ACROSS THE WINDWARD ISLANDS. IN THE UPPER- LEVELS...THE UPPER TROUGH OVER THE W ATLC EXTENDS INTO THE CARIBBEAN ACROSS EASTERN CUBA TO WESTERN PANAMA. ISOLATED TO SCATTERED SHOWERS ARE SEEN NEAR THE SOUTHERN END OF THE TROUGH AXIS OVER THE SW CARIBBEAN. SOUTHWESTERLY WINDS ON THE EAST SIDE OF THE TROUGH ARE TRANSPORTING MID/UPPER LEVEL MOISTURE FROM THE E PACIFIC ACROSS COLOMBIA AND WESTERN VENEZUELA TO BEYOND PUERTO RICO. ...HISPANIOLA... SOUTHWESTERLY FLOW ALOFT ASSOCIATED WITH THE UPPER TROUGH OVER THE W CARIBBEAN WILL CONTINUE TO AFFECT THE ISLAND OVER THE NEXT COUPLE OF DAYS. THIS WILL COMBINE WITH LOW LEVEL MOISTURE TO PRODUCE SCATTERED SHOWERS AND ISOLATED TSTMS DURING THE AFTERNOON AND EARLY EVENING HOURS. ATLANTIC OCEAN... TROPICAL STORM ANA...CURRENTLY LOCATED N OF AREA...MADE LANDFALL AT 0600 AM EDT...1000 UTC...ALONG THE COAST OF SOUTH CAROLINA ALMOST MIDWAY BETWEEN MYRTLE BEACH AND NORTH MYRTLE BEACH. THE STORM IS INLAND WHILE WEAKENING. ANA IS FORECAST TO BECOME A TROPICAL DEPRESSION LATER TODAY. THIS TROPICAL CYCLONE IS EXPECTED TO PRODUCE RAINFALL ACCUMULATIONS OF 2-4 INCHES, WITH ISOLATED AMOUNTS OF 6 INCHES OVER EASTERN PORTIONS OF NORTH CAROLINA AND SOUTH CAROLINA DURING THE REST OF TODAY. MAXIMUM SUSTAINED WINDS HAVE DIMINISHED TO 40 MPH WITH HIGHER GUSTS. SWELLS GENERATED BY ANA ARE AFFECTING PORTIONS OF THE SOUTHEASTERN U.S. COAST AND WILL LIKELY CAUSE LIFE-THREATENING SURF AND RIP CURRENTS. PLEASE SEE LATEST NHC ADVISORIES. A 1032 MB HIGH PRES LOCATED N OF THE FORECAST AREA NEAR 37N56W COVERS THE CENTRAL AND W ATLANTIC. THIS SYSTEM IS FORECAST TO MOVE SE TO A POSITION NEAR 32N53W IN ABOUT 24 HOURS WHILE SLIGHTLY WEAKENING. THE SAHARAN AIR LAYER TRACKING PRODUCT FROM UW-CIMSS INDICATES AFRICAN DUST REACHING THE LESSER ANTILLES. ALOFT...A TROUGH/RIDGE/TROUGH PATTERN DOMINATES THE AREA. AN UPPER-LEVEL TROUGH IS OVER THE WESTERN ATLC AND EXTENDS FROM AN UPPER-LEVEL LOW LOCATED NEAR 28N73W TO EASTERN CUBA. UPPER DIFFLUENCE AHEAD OF THE TROUGH IS HELPING TO INDUCE SOME SHOWER ACTIVITY MAINLY FROM 23N-25N BETWEEN 70W-74W. A LARGE UPPER RIDGE COVERS THE REMAINDER OF THE W AND CENTRAL ATLC. AN UPPER TROUGH N OF 28N IN THE E/CENTRAL ATLC IS SUPPORTING A COLD FRONT THAT ENTERS THE REGION NEAR 31N32W THEN CONTINUES SW TO NEAR 26N44W WHERE IT BEGINS TO DISSIPATE. ISOLATED TO SCATTERED SHOWERS ARE ASSOCIATED WITH THE FRONTAL BOUNDARY. A NARROW SURFACE RIDGE COVERS THE REMAINDER OF THE ATLC S OF THE FRONT. MAINLY MODERATE TO FRESH TRADE WINDS ARE OBSERVED ACROSS THE TROPICAL ATLC BASED ON SCATTEROMETER DATA. FOR ADDITIONAL INFORMATION PLEASE VISIT HTTP://WWW.HURRICANES.GOV/MARINE $$ GR