000 AXNT20 KNHC 311042 TWDAT TROPICAL WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 805 AM EDT WED JUL 31 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 1015 UTC. ...TROPICAL WAVES... TROPICAL WAVE IN THE TROPICAL ATLC EXTENDS FROM 19N40W ALONG 14N41W TO 8N38W MOVING W-NW NEAR 15-20 KT. WAVE IS EMBEDDED WITHIN A NARROW SURGE OF MODERATE MOISTURE AS DEPICTED ON THE TOTAL PRECIPITABLE WATER IMAGERY. THE NOAA GOES R SATELLITE SHOWS THE WAVE AT THE LEADING EDGE OF A DENSE SAHARAN DUST LAYER WHICH IS LIMITING SHOWER ACTIVITY. TROPICAL WAVE OVER THE SW ATLC/CENTRAL CARIBBEAN EXTENDS FROM 25N78W TO 18N78W MOVING W 15-20 KT. WAVE IS EMBEDDED WITHIN AN AREA OF DEEP MOISTURE THAT COVERS THE W ATLC AND THE NW CARIBBEAN AS DEPICTED ON THE TOTAL PRECIPITABLE WATER IMAGERY. WAVE IS MOVING W OF AN UPPER LOW THAT COVERS THE W ATLC WHICH IS ENHANCING ANY SHOWER ACTIVITY IN THE VICINITY NOT BY THE TROPICAL WAVE. ...ITCZ/MONSOON TROUGH... THE MONSOON TROUGH EXTENDS ACROSS AFRICA INTO THE E TROPICAL ATLC NEAR 20N16W AND CONTINUES THROUGH A WEAK 1011 MB LOW NEAR 14N25W THEN ALONG 10N31W TO 7N38W WHERE THE ITCZ BEGINS AND CONTINUES ALONG 6N47W TO SOUTH AMERICA NEAR 7N58W. SCATTERED MODERATE/ISOLATED STRONG CONVECTION IS FROM 7N-10N BETWEEN 13W- 18W. SCATTERED MODERATE CONVECTION IS FROM 6N-9N BETWEEN 29W- 32W. ...DISCUSSION... GULF OF MEXICO... A BROAD UPPER RIDGE ANCHORED OVER W TEXAS/SE NEW MEXICO EXTENDS E ACROSS THE SE CONUS ALONG THE N GULF COAST AND INTO THE W ATLC GIVING THE GULF NE TO E FLOW ALOFT. A RIDGE AXIS EXTENDS FROM THIS MAIN RIDGE E-SE OVER CUBA TO JAMAICA. A SECOND UPPER RIDGE EXTENDS ACROSS S MEXICO TO OVER CENTRAL AMERICA. SCATTERED SHOWERS/ISOLATED THUNDERSTORMS ARE OVER THE STRAITS OF FLORIDA S OF 25N BETWEEN 81W-85W. A SURFACE RIDGE ANCHORED IN THE W/CENTRAL ATLC EXTENDS FROM THE W ATLC ACROSS FLORIDA TO TEXAS AND NE MEXICO WITH A WEAK 1020 MB HIGH NEAR 29N86W. THE GULF HIGH WILL WEAKEN AS DRIFTS S THROUGH SUN. THE TROPICAL WAVE IN THE SW ATLC WILL ENTER THE SE GULF EARLY THU. CARIBBEAN SEA... THE UPPER RIDGE ANCHORED IN THE E PACIFIC EXTENDS ACROSS CENTRAL AMERICA TO OVER THE THE GULF OF HONDURAS. THE MAIN UPPER RIDGE OVER THE GULF OF MEXICO EXTENDS A RIDGE AXIS E-SE OVER CUBA TO JAMAICA PROVIDING DIFFLUNCE ALONG TO GENERATE SCATTERED SHOWERS/ ISOLATED THUNDERSTORMS FROM 19N-21N BETWEEN THE GULF OF GONAVE AND 84W INCLUDING THE CAYMAN ISLANDS. THE MONSOON TROUGH EXTENDS ALONG 9N/10N FROM COLOMBIA TO COSTA RICA ARE GENERATING SCATTERED SHOWERS/ISOLATED THUNDERSTORMS S OF 10N E OF 80W AND S OF 12N W OF 80W. W ATLC/CENTRAL CARIBBEAN TROPICAL WAVE WILL MOVE INTO THE SE GULF EARLY THU. HISPANIOLA... SKIES HAVE CLEARED OVERNIGHT ACROSS THE ENTIRE ISLAND. SCATTERED SHOWERS/ISOLATED THUNDERSTORMS REMAIN IN THE GULF OF GONAVE DUE TO AN UPPER RIDGE THAT EXTENDS FROM W CUBA TO JAMAICA. THE UPPER LOW N OF HISPANIOLA IS STARTING ITS WESTWARD SHIFT AND WILL CONTINUE THROUGH THE STRAITS OF FLORIDA BY SAT AS A SECOND UPPER LOW MOVES TOWARD THE DOMINICAN REPUBLIC FROM THE NE BY THE WEEKEND. AFTERNOON SHOWERS AND THUNDERSTORMS WILL CONTINUE OVER THE NEXT FEW DAYS. ATLANTIC OCEAN... THE UPPER RIDGE OVER THE GULF OF MEXICO EXTENDS INTO THE W ATLC ALONG 31N TO 76W. AN UPPER LOW IS TO THE S CENTERED NEAR 24N72W. THIS UPPER LOW IS GENERATING SCATTERED SHOWERS/THUNDERSTORMS WITHIN 60 NM OF LINE FROM 21N70W TO THE TURKS AND CAICOS NEAR 22N75W. A SECOND LARGER UPPER LOW IS IN THE CENTRAL ATLC NEAR 24N53W SUPPORTING A SURFACE TROUGH THAT EXTENDS FROM 28N47W TO TO 20N51W AND GENERATING CLUSTERS OF SCATTERED SHOWERS/ISOLATED THUNDERSTORMS WITHIN 180 NM W OF THE TROUGH N OF 24N. THE REMAINDER OF THE ATLC IS DOMINATED BY A SURFACE RIDGE ANCHORED BY A 1023 MB HIGH NEAR BERMUDA AND A SECOND 1023 MB HIGH IN THE E ATLC NEAR 29N38W. SURFACE RIDGE WILL SHIFT S TO NEAR 27N FRI THROUGH SUN. THE W ATLC/CENTRAL CARIBBEAN TROPICAL WAVE WILL WILL REACH S FLORIDA TONIGHT. FOR ADDITIONAL INFORMATION PLEASE VISIT HTTP://WWW.HURRICANES.GOV/MARINE $$ PAW