000 AXNT20 KNHC 111757 TWDAT TROPICAL WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 205 PM EDT SAT JUL 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 1200 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 1715 UTC. ...TROPICAL WAVES... TROPICAL WAVE EXTENDS FROM 10N27W TO 18N25W MOVING W AT AROUND 15 KT. THE WAVE COINCIDES WITH A 700 MB TROUGH AXIS. MODERATE TO HIGH MOISTURE IS S OF 15N IN THE WAVE ENVIRONMENT WITH SAHARAN DUST N OF 15N. ISOLATED MODERATE CONVECTION IS FROM 05N TO 12N BETWEEN 22W AND 26W. TROPICAL WAVE EXTENDS FROM 06N43W TO 17N42W MOVING W AT 20 KT OVER THE PAST 24 HOURS. THE WAVE IS ALONG THE LEADING EDGE OF A NORTHWARD SURGE IN TROPICAL MOISTURE OVER THE CENTRAL ATLC. SAHARAN DUST IS ALSO EVIDENT IN THE WAVE ENVIRONMENT...WHICH IS INHIBITING DEEP CONVECTION ALONG THIS WAVE. TROPICAL WAVE EXTENDS FROM 10N68W TO 18N66W MOVING W AT 15 TO 20 KT OVER THE PAST 24 HOURS. THIS WAVE IS AT THE LEADING EDGE OF A POLEWARD SURGE IN MODERATE MOISTURE. A SURFACE WIND SHIFT FROM THE EAST-NORTHEAST TO THE EAST-SOUTHEAST IS ALSO EVIDENT ON SCATTEROMETER IMAGERY...CONFIRMING THE POSITION OF THE WAVE. ISOLATED MODERATE CONVECTION IS FROM 16N TO 20N BETWEEN 62W AND 65W. ...ITCZ/MONSOON TROUGH... THE MONSOON TROUGH EXTENDS FROM THE AFRICAN COAST NEAR 12N16W TO 11N25W TO 09N31W...WHERE THE ITCZ BEGINS AND CONTINUES TO 07N41N AND THE RESUMES W OF THE CENTRAL ATLC TROPICAL WAVE NEAR 06N45W TO THE AFRICAN COAST NEAR 06N58W. ASIDE FROM CONVECTION ASSOCIATED WITH THE EASTERN ATLC TROPICAL WAVE...ISOLATED MODERATE CONVECTION IS FROM 05N TO 11N BETWEEN 32W AND 41W. ...DISCUSSION... GULF OF MEXICO... UPPER LEVEL RIDGING EXTENDS FROM TX AND OVER THE NW GULF...WITH ANOTHER RIDGE EXTENDING FROM THE E PACIFIC NORTHWARD OVER THE SW GULF. UPPER LEVEL DIFFLUENCE BETWEEN THESE TWO FEATURES IS SUPPORTING ISOLATED MODERATE CONVECTION FROM 20N TO 23N BETWEEN 93W AND THE MEXICO COAST. AN UPPER LEVEL LOW CENTERED BETWEEN THE BAHAMAS AND CUBA IS PRODUCING CYCLONIC FLOW OVER THE EASTERN GULF. A WEAK DISTURBANCE BETWEEN THE TX RIDGE AND UPPER LOW IS SUPPORTING A BAND OF SCATTERED THUNDERSTORMS WITHIN 30 NM OF A LINE FROM 28N92W TO KEY WEST. A SURFACE TROUGH OVER THE EASTERN GULF FROM 31N83W TO 26N84W SUPPORTS ISOLATED THUNDERSTORMS WITHIN 50 NM OF THE TROUGH AXIS. A 1022 MB HIGH CENTERED NEAR 30N87W ANCHORS A RIDGE AXIS THAT EXTENDS FROM LOUISIANA AND ACROSS N FL. MAINLY NW WINDS OF 10 KT COVER THE NE GULF. E TO SE WINDS OF 10 TO 15 KT COVER THE MAJORITY OF THE REMAINDER OF THE GULF. OVER THE NEXT 24 HOURS EXPECT SCATTERED THUNDERSTORMS TO BE POSSIBLE OVER THE SW GULF AND EASTERN GULF. CARIBBEAN SEA... AN UPPER LOW CENTERED BETWEEN THE BAHAMAS AND CUBA EXTENDS A TROUGH AXIS SW TO NICARAGUA. ISOLATED THUNDERSTORMS ARE OVER THE NW CARIBBEAN FROM 17N TO 22N BETWEEN 79W AND 87W. SW MID TO UPPER LEVEL FLOW AROUND THE LOW IS PULLING MOISTURE NE FROM THE SW CARIBBEAN TOWARD HISPANIOLA. THIS IS LIKELY PRODUCING SHOWERS OVER THE CENTRAL CARIBBEAN BETWEEN 70W AND 76W. SHOWERS AND CONVECTION IS ALSO BEING PRODUCED BY A TROPICAL WAVE OVER THE EASTERN CARIBBEAN. PLEASE SEE THE TROPICAL WAVES SECTION FOR MORE DETAILS. THE COMBINATION OF DEEP MOISTURE AND WEAK UPPER LEVEL DIFFLUENCE SUPPORTS ISOLATED MODERATE CONVECTION FROM 11N TO 16N BETWEEN 59W AND 62W...INCLUDING A PORTION OF THE LEEWARD ISLANDS. ANOTHER AREA OF UPPER DIFFLUENCE OVER THE SW CARIBBEAN SUPPORTS SCATTERED MODERATE CONVECTION S OF 13N W OF 80W. OVER THE NEXT 24 HOURS CONVECTION IS EXPECTED TO CONTINUE OVER THE EASTERN CARIBBEAN AND BETWEEN 20N AND CUBA. ...HISPANIOLA... AN UPPER LOW BETWEEN THE BAHAMAS AND CUBA IS DRAWING ABUNDANT MID TO UPPER LEVEL MOISTURE NE ACROSS THE ISLAND TODAY. A TROPICAL WAVE IS ALSO MOVING EASTWARD FROM PUERTO RICO TOWARD THE ISLAND THIS AFTERNOON. THE COMBINATION OF THESE FEATURES WILL PRODUCE CLOUDINESS WITH SCATTERED SHOWERS AND ISOLATED THUNDERSTORMS ACROSS THE ISLAND THROUGH SUNDAY. ATLANTIC OCEAN... AN UPPER LOW IS CENTERED BETWEEN THE BAHAMAS AND CUBA...WITH AN AXIS EXTENDING NE ACROSS THE WESTERN ATLC TO NEAR 30N55W. NUMEROUS MODERATE CONVECTION IS WITHIN 125 NM OF 24N76W...INCLUDING MUCH OF THE CENTRAL BAHAMAS. SCATTERED THUNDERSTORMS ARE FROM 20N TO 24N BETWEEN 66W AND 74W. SCATTERED THUNDERSTORMS ARE ALSO ALONG THE TROUGH AXIS WITHIN 50 NM OF A LINE FROM 26N74W TO 31N57W. SURFACE RIDGING ANCHORED BY A 1027 MB HIGH CENTERED NEAR 33N32W DOMINATES THE CENTRAL AND EASTERN ATLC. TWO TROPICAL WAVES ARE OVER THE TROPICAL ATLC. PLEASE SEE THE TROPICAL WAVES SECTION FOR MORE DETAILS. FOR ADDITIONAL INFORMATION PLEASE VISIT HTTP://WWW.HURRICANES.GOV/MARINE $$ LATTO