000 AXNT20 KNHC 062340 TWDAT TROPICAL WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 805 PM EDT FRI JUL 06 2012 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. ...TROPICAL WAVES... TROPICAL WAVE IS ALONG 23N43W TO 14N40W MOVING W NEAR 15 KT. THE WAVE LIES ON THE WRN SIDE OF A SURGE OF DEEP LAYER MOISTURE. THE WAVE ALSO LIES ON THE LEADING EDGE OF A LARGE AREA OF SAHARAN DUST THAT EXTENDS EWD TO THE AFRICAN COAST. NO DEEP CONVECTION IS CURRENTLY NEAR THE WAVE DUE TO THE DRY DUST E OF THE AXIS. ACTIVE TROPICAL WAVE IS MOVING INTO THE WRN CARIBBEAN ALONG 23N78W TO 15N82W MOVING W NEAR 20 KT. TOTAL PRECIPITABLE WATER IMAGERY INDICATES THAT THE WAVE LIES ON THE WRN SIDE OF A LARGE SURGE OF DEEP LAYER MOISTURE COVERING THE CENTRAL CARIBBEAN AND ERN BAHAMAS. SATELLITE IMAGERY ALONG WITH SCATTEROMETER DATA SHOWS LOW-LEVEL CYCLONIC FLOW IS AROUND THE WAVE AXIS. A LARGE CLUSTER OF STRONG CONVECTION COVERS ERN CUBA FROM 20N-22N BETWEEN 74W-80W. SCATTERED MODERATE/ISOLATED STRONG CONVECTION IS FROM 22N-25N BETWEEN 71W-77W ACROSS THE ERN BAHAMAS...AND FROM 14N-19N BETWEEN 77W-85W INCLUDING JAMAICA. SIMILAR ACTIVITY IS ALSO OVER WRN CUBA AND ACROSS HONDURAS AND NICARAGUA. AREAS THAT ARE RECEIVING HEAVY RAINFALL ARE AT RISK FOR LOCALIZED FLOODING AND MUDSLIDES. ...ITCZ/MONSOON TROUGH... THE MONSOON TROUGH EXTENDS ACROSS W AFRICA TO THE COAST OF GUINEA-BISSAU AT 12N16W CONTINUING ACROSS ATLC WATERS TO 8N41W. THE ITCZ BEGINS AT 8N41W TO 5N60W. A LARGE CLUSTER OF STRONG CONVECTION IS MOVING OFF THE AFRICAN COAST FROM 11N-16N BETWEEN 15W-18W. SCATTERED MODERATE/ISOLATED STRONG CONVECTION IS FROM 8N-10N BETWEEN 22W-26W. ...DISCUSSION... GULF OF MEXICO... A BROAD UPPER LEVEL RIDGE COVERS THE ENTIRE ERN CONUS INCLUDING MUCH OF THE GULF OF MEXICO SUPPORTING A WEAK 1018 MB HIGH CENTERED NEAR 27N87W. MOSTLY DRY AIR ALOFT IS PROVIDING FAIR CONDITIONS ACROSS THE GULF WATERS. HOWEVER...A SHORTWAVE UPPER TROUGH MOVING AROUND THE UPPER RIDGE IS PRODUCING AN AREA OF STRONG SHOWERS/THUNDERSTORMS ACROSS LOUISIANA AND THE COASTAL WATERS. THIS CLUSTER OF STORMS APPEARS TO BE MOVING WWD. SOME ISOLATED SHOWERS/THUNDERSTORMS ARE ALSO ACROSS THE SE GULF AND PORTIONS OF THE FLORIDA PENINSULA. LIGHT ANTI-CYCLONIC FLOW IS AROUND THE RIDGE. MOISTURE AND SHOWER ACTIVITY IS EXPECTED TO INCREASE ACROSS THE SE GULF AS A TROPICAL WAVE IN THE WRN CARIBBEAN CONTINUES WWD. WEAK SURFACE RIDGING WILL REMAIN ACROSS THE BASIN THROUGH THE WEEKEND. CARIBBEAN SEA... MOIST CONDITIONS COVER THE NW CARIBBEAN ASSOCIATED WITH A TROPICAL WAVE EXTENDING FROM CENTRAL CUBA TO E OF NICARAGUA. STRONG SHOWERS/THUNDERSTORMS COVER WRN CUBA WITH MORE SCATTERED ACTIVITY OVER WATER. THE ACTIVITY OVER CUBA IS ALSO LIKELY ENHANCED BY DIFFLUENCE ALOFT AROUND THE ERN SIDE OF A BROAD UPPER TROUGH COVERING THE EXTREME SRN GULF OF MEXICO AND THE FAR NW CARIBBEAN. SEE TROPICAL WAVE SECTION ABOVE FOR MORE DETAILS. A LARGE CLUSTER OF STRONG SHOWERS/THUNDERSTORMS IS ALSO IN THE SW CARIBBEAN FROM 10N-12N BETWEEN 80W-83W. EVEN THOUGH THE TROPICAL WAVE IS JUST N OF THIS CLUSTER...IT IS MOST LIKELY ASSOCIATED WITH THE MONSOON TROUGH EXTENDING FROM THE E PACIFIC ACROSS COSTA RICA TO NRN COLOMBIA. THIS SECTION ALSO LIES UNDERNEATH AN AREA OF DIFFLUENCE ALOFT ON THE WRN SIDE OF AN UPPER LEVEL RIDGE COVERING THE SW GULF. THE CENTRAL AND ERN CARIBBEAN IS EXPERIENCING MOSTLY FAIR WEATHER DUE TO DRY AIR ALOFT AROUND AN UPPER LEVEL RIDGE COVERING THE ERN CARIBBEAN. TRADEWIND FLOW OF 15-20 KT IS ACROSS MUCH OF THE BASIN REACHING 25 KT IN THE CENTRAL CARIBBEAN. EXPECT THE TROPICAL WAVE TO CONTINUE MOVING WWD ACROSS THE BASIN WITH FAIR WEATHER REMAINING IN ITS WAKE. ATLANTIC OCEAN... DRY AIR ALOFT AROUND A BROAD UPPER LEVEL RIDGE IS PROVIDING FAIR CONDITIONS ACROSS MUCH OF THE WRN ATLC. SHOWERS/THUNDERSTORMS ARE IMPACTING THE ERN BAHAMAS DUE TO A TROPICAL WAVE IN THE WRN CARIBBEAN. ANOTHER UPPER LEVEL RIDGE IS ALONG 63W PROVIDING MORE FAIR WEATHER AND SUPPORTING WEAK SURFACE RIDGING. AN UPPER LEVEL LOW IS TO THE E CENTERED NEAR 27N54W...BUT IS NOT CAUSING ANY SIGNIFICANT WEATHER. A BROAD UPPER LEVEL RIDGE ACROSS THE NRN ATLC SUPPORTS A BROAD SURFACE RIDGE ANCHORED BY A 1030 MB AZORES HIGH...WHICH IS PROVIDING FAIR CONDITIONS ACROSS THE CENTRAL AND ERN ATLC. UPPER LEVEL RIDGING ALSO COVERS THE TROPICAL ATLC CENTERED NEAR 2140W. THE LAST VISIBLE SATELLITE IMAGES OF THE DAY INDICATE A LARGE AREA OF DUST EXTENDING FROM THE AFRICAN COAST TO THE TROPICAL WAVE IN THE TROPICAL ATLC. DUST IS ALSO PRESENT W OF THE WAVE TO THE ERN CARIBBEAN. FOR ADDITIONAL INFORMATION PLEASE VISIT HTTP://WWW.HURRICANES.GOV/MARINE $$ WALTON