000 AXNT20 KNHC 122359 TWDAT TROPICAL WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 805 PM EDT FRI JUL 12 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 1800 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 2315 UTC. ...TROPICAL WAVES... TROPICAL WAVE IN THE CENTRAL TROPICAL ATLC EXTENDS FROM 19N34W TO 10N35W DRIFTING W. THE LOCATION OF THE WAVE IS WITH THE MID LEVEL LOW NEAR 11N34W RATHER THAN THE UPPER LEVEL LOCATION OF THE PAST FEW DAYS. WAVE REMAINS EMBEDDED WITHIN A SURGE OF DEEP MOISTURE AS DEPICTED ON THE TOTAL PRECIPITABLE WATER IMAGERY. SCATTERED MODERATE CONVECTION IS FROM 8N-11N BETWEEN 33W-36W. TROPICAL WAVE IN THE W CARIBBEAN EXTENDS FROM CUBA NEAR 23N83W TO OVER HONDURAS/NICARAGUA NEAR 12N84W MOVING W NEAR 10 KT. WAVE REMAINS EMBEDDED WITHIN AN AREA DEEP MOISTURE THAT COVERS THE CARIBBEAN W OF 77W AS DEPICTED ON THE TOTAL PRECIPITABLE WATER IMAGERY. SCATTERED SHOWERS/ISOLATED THUNDERSTORMS ARE WITHIN 260 NM E OF THE WAVE N OF 16N TO ACROSS CUBA. ...ITCZ/MONSOON TROUGH... THE MONSOON TROUGH EXTENDS ACROSS AFRICA INTO THE E TROPICAL ATLC NEAR 12N17W AND CONTINUES ALONG 10N20W TO 9N30W. THE ITCZ BEGINS W OF THE TROPICAL WAVE NEAR 10N36W AND CONTINUES ALONG 9N49W TO SOUTH AMERICA NEAR 7N59W. CLUSTERS OF SCATTERED MODERATE CONVECTION ARE WITHIN 180 NM S OF THE MONSOON TROUGH E OF 26W TO INLAND OVER W AFRICA. CLUSTERS OF SCATTERED MODERATE/ ISOLATED STRONG CONVECTION ARE INLAND AND WITHIN 60 NM ALONG THE COAST OF SOUTH AMERICA BETWEEN 51W-56W. ...DISCUSSION... GULF OF MEXICO... A BROAD UPPER RIDGE COVERS THE NW GULF ANCHORED OVER THE CENTRAL PLAIN STATES. A NARROW UPPER TROUGH COVERS THE NE GULF WITH THE UPPER LOW OVER THE LOWER GREAT LAKES REGION. A SURFACE TROUGH ENTERS THE NE GULF ACROSS TALLAHASSEE FLORIDA AND EXTENDS ALONG 27N90W TO 28N96W WITH SCATTERED SHOWERS WITHIN 75/90 NM SE OF THE SURFACE TROUGH. AN UPPER TROUGH IS ACROSS THE S GULF EXTENDING FROM AN UPPER LOW IN THE STRAITS OF FLORIDA NEAR 24N81W TO NEAR TAMPICO MEXICO. THIS UPPER TROUGH IS ENHANCING THE ACTIVITY ASSOCIATED WITH THE W CARIBBEAN TROPICAL WAVE. A WEAK SURFACE RIDGE COVERS THE S/CENTRAL GULF AND IS ANCHORED BY A 1015 MB HIGH NEAR 26N92W. SURFACE TROUGH WILL WEAKEN TONIGHT AND DISSIPATE BY SAT EVENING. EASTERLY WINDS WILL PREVAIL ACROSS THE REGION SUN THROUGH WED. CARIBBEAN SEA... THE TROPICAL WAVE IS THE PRIMARY FEATURE IN THE CARIBBEAN THIS EVENING. AN UPPER RIDGE COVERS THE CARIBBEAN E OF 75W AND IS ANCHORED OVER HONDURAS AND IS PROVIDING DIFFLUENCE ALOFT TO GENERATE CLUSTERS OF SCATTERED SHOWERS/ISOLATED THUNDERSTORMS DOTTING THE NW CARIBBEAN N OF 13N W OF 80W TO OVER CENTRAL AMERICA AND THE YUCATAN PENINSULA. THE MONSOON TROUGH EXTENDS ACROSS THE SW CARIBBEAN FROM COLOMBIA NEAR 10N75W ALONG 12N82W TO ACROSS NICARAGUA NEAR 11N84W. THIS IS LEAVING THE REMAINDER OF THE CARIBBEAN E OF 77W UNDER REMARKABLY CLEAR SKIES THIS EVENING. W CARIBBEAN TROPICAL WAVE WILL MOVE INLAND INTO YUCATAN PENINSULA SAT NIGHT. TROPICAL WAVE IN CENTRAL ATLC WILL MOVE W INTO THE E CARIBBEAN TUE. HISPANIOLA... ISOLATED SHOWERS/THUNDERSTORMS ARE DOTTING HISPANIOLA THIS EVENING. THE DEEP MOISTURE HAS MOVED W OF THE ISLAND LIMITING HEAVY SHOWERS. HOWEVER...AFTERNOON SHOWERS/THUNDERSTORMS COULD STILL DOT THE ISLAND THROUGH THE FIRST OF NEXT WEEK. A TROPICAL WAVE WILL MOVE ACROSS THE ISLAND MID WEEK INCREASING THE CHANCE OF HEAVIER PRECIPITATION. ATLANTIC OCEAN... AN UPPER LOW IS CENTERED IN THE STRAITS OF FLORIDA NEAR 24N81W AND COVERS THE SW ATLC S OF 26N W OF 77W. AFTERNOON THUNDERSTORMS THAT HAVE DEVELOPED OVER FLORIDA ARE MOVING E WITHIN 45 NM ALONG THE COAST. AN UPPER RIDGE EXTENDS FROM HISPANIOLA TO NEAR 30N72W PROVIDING DIFFLUENCE ALOFT TO GENERATE CLUSTERS OF SCATTERED SHOWERS/ISOLATED THUNDERSTORMS S OF 29N BETWEEN 73W-79W. SCATTERED SHOWERS/ISOLATED THUNDERSTORMS ARE WITHIN 30 NM OF LINE FROM 29N78W TO 33N76W. A SECOND UPPER LOW IS OVER THE W/CENTRAL ATLC CENTERED NEAR 27N61W SUPPORTING A SURFACE TROUGH THAT EXTENDS FROM 32N60W TO 24N59W AND GENERATING SCATTERED SHOWERS/ISOLATED THUNDERSTORMS FROM 28N-33N BETWEEN 57W-65W. THE REMAINDER OF THE ATLC IS DOMINATED BY A SURFACE RIDGE ANCHORED BY A 1022 MB HIGH NEAR 30N36W AND A 1024 MB HIGH NE NEAR BERMUDA. W/CENTRAL ATLC SURFACE TROUGH WILL MOVE W TOWARDS FLORIDA PENINSULA THROUGH TUE. FOR ADDITIONAL INFORMATION PLEASE VISIT HTTP://WWW.HURRICANES.GOV/MARINE $$ PAW