000 AXNT20 KNHC 030555 TWDAT TROPICAL WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 205 AM EDT WED JUL 03 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 0000 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 0515 UTC. ...TROPICAL WAVES... TROPICAL WAVE E OF THE CAPE VERDE ISLANDS EXTENDS ALONG 19W/20W FROM 7N-16N MOVING W 10-15 KT. WAVE IS EMBEDDED WITHIN A SURGE OF MODERATE TO DEEP MOISTURE AS DEPICTED BY THE TOTAL PRECIPITABLE WATER IMAGERY. A MID LEVEL SWIRL IS NOTED ON SATELLITE IMAGERY ALONG THE N PORTION OF THE WAVE AXIS. NO ASSOCIATED DEEP CONVECTION. TROPICAL WAVE IN THE CENTRAL TROPICAL ATLC EXTENDS FROM 14N33W TO 5N39W MOVING W NEAR 20 KT. WAVE REMAINS EMBEDDED WITHIN A SURGE OF DEEP MOISTURE AS DEPICTED BY THE TOTAL PRECIPITABLE WATER IMAGERY. SMALL CLUSTERS OF SCATTERED MODERATE CONVECTION ARE WITHIN 150 NM EITHER SIDE OF THE WAVE AXIS. TROPICAL WAVE IN THE W TROPICAL ATLC EXTENDS ALONG 59W/60W FROM 12N-21N MOVING W NEAR 20 KT. THIS WAVE IS WITHIN AN AREA VOID OF DEEP MOISTURE AS DEPICTED BY THE TOTAL PRECIPITABLE WATER IMAGERY. SCATTERED/BROKEN LOW LEVEL CLOUDS ARE OBSERVED ON SATELLITE IMAGERY W OF 54W ACROSS THE LESSER ANTILLES WITH NO ASSOCIATED DEEP CONVECTION. TROPICAL WAVE THAT WAS IN THE CARIBBEAN IS NOW A SURFACE TROUGH AT 03/0300 UTC THAT HAS BEEN DRAWN NW IN RESPONSE TO AN UPPER RIDGE/UPPER TROUGH OVER THE E GULF OF MEXICO/W ATLC. ...ITCZ/MONSOON TROUGH... THE MONSOON TROUGH EXTENDS ACROSS AFRICA INTO THE E TROPICAL ATLC NEAR 11N15W AND CONTINUES ALONG 9N20W TO 10N25W WHERE THE ITCZ BEGINS AND CONTINUES ALONG 11N30W TO 10N34W. THE ITCZ RESUMES W OF THE TROPICAL WAVE NEAR 8N39W AND CONTINUES ALONG 6N45W TO ACROSS THE EQUATOR INTO SOUTH AMERICA NEAR 50W. CLUSTERS OF SCATTERED MODERATE/ISOLATED STRONG CONVECTION ARE S OF 2N TO INLAND OVER SOUTH AMERICA BETWEEN 45W-49W. CLUSTERS OF SCATTERED MODERATE CONVECTION ARE WITHIN 180 NM S OF THE MONSOON TROUGH BETWEEN 15W-25W. ...DISCUSSION... GULF OF MEXICO... BROAD UPPER TROUGH COVERS THE GULF N OF 22N W OF 86W EXTENDING FROM AN UPPER LOW OVER THE UPPER MISSISSIPPI VALLEY AND SUPPORTING A SURFACE TROUGH THAT AT 03/0300 UTC EXTENDS INTO THE GULF OVER SE LOUISIANA NEAR 29N91W AND CONTINUES ALONG 26N91W TO 24N93W WITH SCATTERED SHOWERS/ISOLATED THUNDERSTORMS WITHIN 90 NM E OF THE TROUGH N OF 27N. SCATTERED SHOWERS AND POSSIBLE ISOLATED THUNDERSTORMS ARE FROM 20N-25N W OF 94W TO INLAND OVER MEXICO. A SURFACE TROUGH...PREVIOUSLY A TROPICAL WAVE...IS BENEATH AN UPPER RIDGE AND EXTENDS FROM THE CARIBBEAN ACROSS CUBA NEAR HAVANA THROUGH THE STRAITS OF FLORIDA INTO THE W ATLC PROVIDING DIFFLUNCE ALOFT TO GENERATE SCATTERED SHOWERS/ISOLATED THUNDERSTORMS E OF 86W TO ACROSS FLORIDA. A THIRD SURFACE TROUGH EXTENDS FROM 22N90W TO INLAND OVER THE W PORTION OF THE YUCATAN PENINSULA WITH SCATTERED SHOWERS/ISOLATED THUNDERSTORMS S OF 22N BETWEEN 86W-93W INCLUDING PORTIONS OF THE YUCATAN PENINSULA. THE N GULF SURFACE TROUGH WILL BEGIN TO LIFT TO THE NW AND SLOWLY DISSIPATE LATE TONIGHT THROUGH THU. A SURFACE RIDGE WILL REDEVELOP AND SHIFT N AS THE TROUGH DISSIPATES. THE WEAK SURFACE TROUGH OVER THE YUCATAN PENINSULA WILL MOVE SLOWLY W ACROSS THE E BAY OF CAMPECHE TONIGHT THEN W-NW ACROSS THE W GULF WED THROUGH FRI. THE SURFACE TROUGH PREVIOUSLY THE N PORTION OF A TROPICAL WAVE WILL MOVE NW ACROSS THE YUCATAN CHANNEL AND THE SE GULF TONIGHT AND WED. CARIBBEAN SEA... A BROAD UPPER RIDGE COVERS THE CARIBBEAN W OF 70W AND IS ANCHORED ALONG THE COAST OF N BELIZE ON THE YUCATAN PENINSULA. THIS UPPER RIDGE ALSO EXTENDS A RIDGE AXIS N ACROSS CUBA/THE STRAITS OF FLORIDA INTO THE W ATLC. AN UPPER LOW IS N OF HISPANIOLA AND EXTENDS ACROSS THE GREATER ANTILLES TO OVER THE NE CARIBBEAN N OF 16N BETWEEN 66W-73W. THE AREA W OF 80W IS DOMINATED BY DEEP MOISTURE AS DEPICTED BY THE TOTAL PRECIPITABLE WATER IMAGERY. A SURFACE TROUGH...PREVIOUSLY A TROPICAL WAVE... IS BENEATH THE UPPER RIDGE AND EXTENDS FROM 19N84W ACROSS CUBA INTO THE SE GULF OF MEXICO NEAR HAVANA. A SECOND SURFACE TROUGH...PREVIOUSLY A PORTION OF THE SAME TROPICAL WAVE...IS ALSO BENEATH AN UPPER RIDGE AND EXTENDS ALONG 85W S OF 17N TO OVER HONDURAS AND NICARAGUA. THE UPPER RIDGE IS PROVIDING DIFFLUNCE ALOFT TO GENERATE SCATTERED SHOWERS/ISOLATED THUNDERSTORMS N OF 18N W OF 78W AND S OF 18N W OF 82W TO INLAND OVER CENTRAL AMERICA. A SECOND UPPER RIDGE COVERS THE REMAINDER OF THE E CARIBBEAN AND IS ANCHORED IN THE TROPICAL ATLC. THE MONSOON TROUGH EXTENDS ACROSS PORTIONS OF PANAMA AND COSTA RICA BUT IS NOT PRODUCING ANY SIGNIFICANT WEATHER. THE N SURFACE TROUGH IS EXPECTED TO MOVE NW ACROSS THE NW CARIBBEAN AND YUCATAN CHANNEL TONIGHT AND INTO THE SE GULF OF MEXICO EARLY WED. THE S SURFACE TROUGH WILL CONTINUE WESTWARD AND ACROSS CENTRAL AMERICA TONIGHT AND WED. A TROPICAL WAVE JUST E OF THE LESSER ANTILLES WILL MOVE INTO THE E CARIBBEAN WED THEN MOVE ACROSS THE CENTRAL CARIBBEAN THU AND ACROSS THE W CARIBBEAN FRI AND SAT. A SECOND TROPICAL WAVE WILL REACH THE E CARIBBEAN SAT. HISPANIOLA... AN UPPER LOW IS N OF HISPANIOLA AND EXTENDS ACROSS THE ISLAND TO 16N. CURRENTLY THE AFTERNOON SHOWERS AND THUNDERSTORMS ARE DIMINISHING. AFTERNOON SHOWERS AND THUNDERSTORMS COULD DEVELOP OVER THE NEXT FEW DAYS WITH THE NEXT TROPICAL WAVE CROSSING THE ISLAND FRI AND SAT. ATLANTIC OCEAN... THE UPPER RIDGE AXIS THAT EXTENDS FROM THE NW CARIBBEAN ACROSS CUBA NEAR HAVANA THROUGH THE STRAITS OF FLORIDA INTO THE W ATLC NEAR 25N80W AND CONTINUES N TO 30N79W PROVIDING DIFFLUNCE ALOFT TO GENERATE SCATTERED SHOWERS AND POSSIBLE ISOLATED THUNDERSTORMS W OF 77W TO OVER FLORIDA AND CUBA. A CUT-OFF UPPER LOW IS N OF HISPANIOLA NEAR 24N72W CROSSING THE GREATER ANTILLES FROM PUERTO RICO TO THE WINDWARD PASSAGE AND IS GENERATING ISOLATED SHOWERS WITH POSSIBLE ISOLATED THUNDERSTORMS S OF 23N TO HISPANIOLA BETWEEN 67W-70W. A SURFACE TROUGH EXTENDS FROM 25N61W ALONG 28N65W TO 32N66W BUT IS NOT GENERATING ANY SIGNIFICANT WEATHER. OTHERWISE A LARGE SURFACE RIDGE DOMINATES THE ATLC ANCHORED BY A SERIES OF HIGH WELL N OF THE DISCUSSION AREA. W ATLC SURFACE RIDGE WILL REALIGN E TO W ALONG 35N TONIGHT THROUGH SAT. THE N PORTION OF TROPICAL WAVE JUST E OF THE LESSER ANTILLES WILL MOVE W ACROSS SW ATLC WED THROUGH FRI. FOR ADDITIONAL INFORMATION PLEASE VISIT HTTP://WWW.HURRICANES.GOV/MARINE $$ PAW