000 AXNT20 KNHC 101048 TWDAT TROPICAL WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 805 AM EDT FRI MAY 10 2013 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 1045 UTC. ...ITCZ/MONSOON TROUGH... THE MONSOON TROUGH EXTENDS FROM THE COAST OF GUINEA-BISSAU NEAR 11N15W TO 5N23W. THE INTERTROPICAL CONVERGENCE ZONE AXIS EXTENDS FROM 5N23W TO 2N40W TO THE COAST OF BRAZIL AT 0N50W. WIDELY SCATTERED MODERATE CONVECTION IS FROM 1N-7N BETWEEN 7W-25W. WIDELY SCATTERED MODERATE CONVECTION IS N OF THE ITCZ FROM 4N-6N BETWEEN 33W-50W. ...DISCUSSION... GULF OF MEXICO... SURFACE RIDGING IS OVER THE GULF OF MEXICO FROM THE W ATLANTIC WITH AXIS ALONG 30N. 10-15 SW SURFACE FLOW IS OVER THE GULF WITH STRONGER WINDS OVER THE W GULF WHERE THE SURFACE PRESSURE GRADIENT TIGHTENS A BIT. SCATTERED MODERATE TO ISOLATED STRONG CONVECTION EXTENDS FROM CENTRAL ALABAMA TO E TEXAS TO INCLUDE THE COAST OF LOUISIANA. RADAR IMAGERY DEPICTS AN EMBEDDED SQUALL LINE MOVING E. ELSEWHERE ISOLATED MODERATE CONVECTION HAS ADVECTED OVER S FLORIDA AND THE STRAITS OF FLORIDA FROM THE BAHAMAS. MOSTLY FAIR WEATHER IS OVER THE REMAINDER OF THE GULF. IN THE UPPER LEVELS...AN UPPER LEVEL RIDGE IS OVER THE GULF WITH AXIS ALONG 92W. UPPER LEVEL MOISTURE AND SCATTERED HIGH CLOUDS ARE OVER MOST OF THE GULF. EXPECT IN 24 HOURS FOR THE TAIL END OF A COLD FRONT TO BE OVER S LOUISIANA AND THE NW GULF WITH CONVECTION...AND CONTINUED SURFACE RIDGING OVER THE E GULF. CARIBBEAN SEA... AS OF 0900 UTC...A 1010 MB LOW IS CENTERED OVER N COLOMBIA NEAR 8N74W. A MONSOON TROUGH EXTENDS W FROM THE LOW TO COSTA RICA NEAR 10N93W. SCATTERED MODERATE TO ISOLATED STRONG CONVECTION IS S OF 12N FROM LAKE MARACAIBO VENEZUELA TO COSTA RICA. A SURFACE TROUGH EXTENDS FROM THE STRAITS OF FLORIDA AT 25N80W TO SE CUBA AT 20N77W MOVING WNW. ISOLATED MODERATE CONVECTION IS MOSTLY E OF THE TROUGH AXIS. ANOTHER SURFACE TROUGH EXTENDS FROM THE S BAHAMAS NEAR 24N72W TO HAITI AT 19N72W. SCATTERED SHOWERS PERSIST OVER HISPANIOLA. FURTHER E...THE TAIL END OF A SHEARLINE IS OVER THE LEEWARD ISLANDS FROM 15N60W TO PUERTO RICO AT 18N67W. SCATTERED SHOWERS ARE WITHIN 60 NM OF THE SHEARLINE. IN THE UPPER LEVELS... THE BASE OF AN UPPER LEVEL TROUGH IS OVER THE NORTH CENTRAL CARIBBEAN WITH UPPER LEVEL DIFFLUENCE OVER THE LEEWARD ISLANDS ENHANCING THE SCATTERED SHOWERS. UPPER LEVEL SUBSIDENCE IS OVER THE NW CARIBBEAN. SIGNIFICANT UPPER LEVEL MOISTURE AND BROKEN HIGH CLOUD OVER THE REMAINDER OF THE CARIBBEAN. EXPECT OVER THE NEXT 24 HOURS FOR CONVECTION TO CONTINUE OVER THE SW CARIBBEAN...AND FOR CONTINUED SHOWERS TO BE OVER THE LEEWARD ISLANDS DUE TO THE SHEARLINE. ATLANTIC OCEAN... THE SURFACE TROUGH THAT EXTENDS FROM THE S BAHAMAS NEAR 24N72W TO HAITI AT 19N72W IS PRODUCING SCATTERED MODERATE CONVECTION FROM 20N-30N BETWEEN 66W-72W. A 1029 MB HIGH IS OVER THE CENTRAL ATLANTIC NEAR 35N54W PRODUCING FAIR WEATHER. A 1018 MB LOW IS OVER THE E ATLANTIC NEAR 30N30W. A SURFACE TROUGH EXTENDS SW FROM THE LOW TO 26N32W. SCATTERED SHOWERS ARE WITHIN 30 NM OF THE TROUGH. A SHEARLINE IS OVER THE TROPICAL ATLANTIC FROM 18N37W TO 14N55W TO TO THE LEEWARD ISLANDS NEAR 15N60W. SCATTERED SHOWERS ARE WITHIN 90 NM OF THE SHEARLINE. IN THE UPPER LEVELS... AN UPPER LEVEL TROUGH IS OVER THE W ATLANTIC N OF 20N BETWEEN 70W-80W SUPPORTING THE SURFACE TROUGHS. ANOTHER UPPER LEVEL TROUGH IS OVER THE E ATLANTIC BETWEEN 20W-50W SUPPORTING THE SURFACE LOW. EXPECT OVER THE NEXT 24 HOURS FOR CONVECTION TO BE N OF THE LEEWARD ISLANDS...AND CONTINUED SHOWERS TO BE OVER THE BAHAMAS. FOR ADDITIONAL INFORMATION PLEASE VISIT HTTP://WWW.HURRICANES.GOV/MARINE AT THE REQUEST OF METEO-FRANCE AND THE METEOROLOGICAL SERVICES OF HAITI AND THE DOMINICAN REPUBLIC...THE TROPICAL ANALYSIS AND FORECAST BRANCH (TAFB) WILL BEGIN PROVIDING...ON A TEMPORARY BASIS...A SEPARATE DETAILED SECTION WITHIN THE ATLANTIC TROPICAL WEATHER DISCUSSION (TWDAT). IT WILL COVER BOTH HAITI AND THE DOMINICAN REPUBLIC DUE TO THE SHARED GEOGRAPHY OF BOTH COUNTRIES ON THE ISLAND OF HISPANIOLA. THE SECTION BEGINS ON MAY 15 2013 AT 1800 UTC...2 PM EDT. IT WILL PROVIDE GUIDANCE FOR SIGNIFICANT WEATHER EVENTS THAT ARE EXPECTED TO IMPACT THE REGION THROUGH 48 HOURS...WITH THE FOCUS ON ASSESSING THE POTENTIAL FOR HEAVY RAINFALL. $$ FORMOSA