000 AXNT20 KNHC 280550 TWDAT TROPICAL WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 205 AM EDT TUE JUN 28 2011 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. ...SPECIAL FEATURE... BROAD LOW PRESSURE CONTINUES TO COVER THE SRN GULF OF MEXICO WITH A 1006 MB SURFACE LOW LOCATED NEAR 19N92W...JUST E OF A TROPICAL WAVE ALONG 94W/95W. THE LOW CENTER IS NOT WELL DEFINED INDICATED BY A RECENT SCATTEROMETER PASS FROM 0352 UTC. HOWEVER...20-25 KT WINDS ARE INDICATED TO THE N OF THE LOW AND AROUND THE E SIDE OF THE TROPICAL WAVE. CURRENTLY A LARGE CLUSTER OF NUMEROUS CONVECTION IS E OF THE LOW CENTER OVER NRN GUATEMALA AND THE YUCATAN PENINSULA FROM 16N-20N BETWEEN 88W-91W...AND OVER THE NRN YUCATAN PENINSULA FROM 20N-22N BETWEEN 87W-89W. UPPER LEVEL WINDS ARE CURRENTLY NOT FAVORABLE FOR DEVELOPMENT...BUT COULD BECOME SO OVER THE NEXT COUPLE OF DAYS. REGARDLESS OF DEVELOPMENT...SIGNIFICANT MOISTURE WILL REMAIN OVER THE SRN GULF AND YUCATAN PENINSULA LIKELY SUPPORTING STRONG SHOWERS/THUNDERSTORMS ALONG WITH GUSTY WINDS AS THE SYSTEM DRIFTS WNW OVER THE NEXT 48 HOURS. ...TROPICAL WAVES... A TROPICAL WAVE IS ACROSS THE CENTRAL ATLC ALONG 14N38W TO 5N39W MOVING W NEAR 15 KT. A RECENT SCATTEROMETER PASS FROM 0026 UTC SHOWS CLEAR CUT CYCLONIC SURFACE FLOW IS ABOUT THE WAVE AXIS. THE WAVE IS EMBEDDED WITHIN A SURGE OF DEEP LAYER MOISTURE EVIDENT IN TOTAL PRECIPITABLE WATER IMAGERY. SCATTERED MODERATE/STRONG CONVECTION IS W OF THE WAVE AXIS FROM 9N-11N BETWEEN 41W-46W. A TROPICAL WAVE EXTENDS ACROSS WRN PUERTO RICO AND THE ERN CARIBBEAN FROM 20N66W TO 11N68W MOVING W NEAR 15 KT. THE WAVE LIES IN AN AREA OF MODERATE DEEP LAYER MOISTURE THAT IS ACROSS THE ERN CARIBBEAN. AN UPPER LEVEL LOW JUST S OF THE DOMINICAN REPUBLIC IS PROVIDING DIFFLUENCE ALOFT ABOVE THE WAVE AXIS. THIS COMBINATION IS CAUSING A CLUSTER OF STRONG CONVECTION NEAR THE NRN EXTENT OF THE WAVE FROM 19N-20N BETWEEN 64W-67W. MODERATE CONVECTION IS ALSO ACROSS MUCH OF THE DOMINICAN REPUBLIC AND NEAR THE WAVE AXIS FROM 14N-16N BETWEEN 66W-68W. POSSIBLE ISOLATED SHOWERS COVER THE REMAINDER OF THE AREA FROM 14N-21N BETWEEN 64W-72W. THE UPPER LOW IS FORECAST TO DRIFT SW AS THE WAVE MOVES W WHICH WILL CONTINUE TO PLACE THE WAVE UNDER DIFFLUENCE ALOFT. EXPECT CONTINUED SHOWER/THUNDERSTORM ACTIVITY OVER THE CENTRAL CARIBBEAN OVER THE NEXT 24 HOURS. A TROPICAL WAVE IS OVER THE SW GULF OF MEXICO IN THE BAY OF CAMPECHE ALONG 25N94W TO 17N95W DRIFTING WNW. THIS WAVE ALSO LIES UNDER THE DIFFLUENT SIDE OF AN UPPER LEVEL TROUGH OVER THE NW GULF WHICH IS HELPING ENHANCE CONVECTION. CLUSTERS OF NUMEROUS STRONG CONVECTION ARE OVER WRN MEXICO FROM 14N-19N BETWEEN 93W-95W. SCATTERED MODERATE/STRONG CONVECTION IS ALSO W OF THE WAVE AXIS FROM 15N-21N BETWEEN 95W-99W...AND NEAR THE WAVE AXIS FROM 22N-24N BETWEEN 92W-95W. A SURFACE LOW PRESSURE SYSTEM IS ALSO E OF THE WAVE AXIS NEAR THE COAST OF THE YUCATAN PENINSULA. THIS LOW...AS WELL AS THE CONVECTION OVER THE YUCATAN PENINSULA IS DESCRIBED IN THE SPECIAL FEATURES SECTION ABOVE. AT THIS TIME...THE WAVE IS EXPECTED TO STAY SEPARATE FROM THE LOW PRESSURE SYSTEM AND WILL MOVE INLAND OVER NE MEXICO AND DISSIPATE OVER THE NEXT 24 HOURS. ...ITCZ/MONSOON TROUGH... THE MONSOON TROUGH EXTENDS ACROSS AFRICA FROM THE PRIME MERIDIAN AT 23N ALONG 20N08W 16N15W TO 7N19W. THE ITCZ AXIS CONTINUES FROM 7N19W ALONG 7N31W 7N40W 5N57W. A LARGE BURST OF NUMEROUS STRONG CONVECTION IS MOVING OFF THE W AFRICAN COAST FROM 8N-16N BETWEEN 13W-17W...LIKELY ASSOCIATED WITH THE NEXT TROPICAL WAVE. ISOLATED MODERATE/STRONG CONVECTION IS FROM 7N-10N BETWEEN 18W-21W...AND WITHIN 100 NM S OF THE AXIS BETWEEN 28W-33W. SCATTERED MODERATE/STRONG CONVECTION IS N OF BRAZIL FROM EQ-6N BETWEEN 45W-50W. ...DISCUSSION... GULF OF MEXICO... BROAD LOW PRESSURE CONTINUES TO IMPACT MUCH OF THE SRN GULF OF MEXICO AS DISCUSSED IN THE SPECIAL FEATURE SECTION AND TROPICAL WAVE SECTION. MOIST SWLY FLOW ALOFT COVERS MUCH OF THE BASIN BETWEEN AN UPPER LEVEL TROUGH OVER THE NW GULF EXTENDING FROM SRN ALABAMA TO N CENTRAL MEXICO NEAR 22N100W...AND AN UPPER LEVEL RIDGE EXTENDING FROM THE NW CARIBBEAN AND ACROSS THE FLORIDA PENINSULA. THIS PATTERN IS ALSO CREATING A LARGE AREA OF DIFFLUENCE WHICH IS AIDING CONVECTION NEAR BOTH THE TROPICAL WAVE AND THE SURFACE LOW. SCATTERED SHOWERS/THUNDERSTORMS NOT ASSOCIATED WITH EITHER OF THOSE FEATURES ARE ALSO IN THE SE GULF FROM 23N-26N BETWEEN 81W-88W...WITH ISOLATED SHOWERS/THUNDERSTORMS ACROSS FLORIDA AND THE NE GULF. DRY AIR COVERS THE NW GULF BEHIND THE UPPER TROUGH PROVIDING FAIR WEATHER ACROSS THAT PORTION OF THE BASIN. AT THE SURFACE...WEAK SURFACE RIDING IS OVER THE NRN GULF ALONG 28N EXTENDING FROM THE W ATLC. EXPECT SIGNIFICANT MOISTURE TO REMAIN ACROSS THE AREA OVER THE NEXT SEVERAL DAYS WITH A HIGH CHANCE OF PRECIPITATION. CARIBBEAN SEA... PORTIONS OF THE WRN CARIBBEAN ARE FINALLY GETTING SOME RELIEF FROM THE MOISTURE THAT HAS NOW MOVED OVER THE GULF OF MEXICO. HOWEVER...SCATTERED SHOWERS/THUNDERSTORMS STILL REMAIN OVER CENTRAL AMERICA INCLUDING NICARAGUA...HONDURAS...GUATEMALA...AND BELIZE. MOST OF THE ACTIVITY OVER CUBA HAS NOW DIED DOWN LEAVING THE REMAINDER OF THE WRN CARIBBEAN W OF 72W UNDER MOSTLY FAIR CONDITIONS. ALOFT...DRY AIR IS BEING DRAWN OVER THE CENTRAL CARIBBEAN BETWEEN AN UPPER LEVEL RIDGE EXTENDING FROM THE NW CARIBBEAN TO FLORIDA...AND AN UPPER LEVEL LOW STILL SPINNING JUST S OF THE DOMINICAN REPUBLIC NEAR 17N70W. THE UPPER LOW IS INTERACTING WITH A TROPICAL WAVE BETWEEN 66W-68W. THIS IS SUPPORTING ISOLATED SHOWERS N OF 14N BETWEEN 64W-72W...WITH AREAS OF STRONGER ACTIVITY N OF PUERTO RICO AND OVER THE DOMINICAN REPUBLIC. EXPECT SHOWER ACTIVITY TO INCREASE OVER THE N CENTRAL CARIBBEAN AS THE UPPER LOW DRIFTS SW AND THE WAVE MOVES W. ATLANTIC OCEAN... AN UPPER LEVEL TROUGH CONTINUES TO SIT OVER THE NW ATLC SUPPORTING POSSIBLE ISOLATED SHOWERS ALONG A LINE FROM 28N79W TO 32N70W. AN UPPER LEVEL RIDGE IS TO THE E EXTENDING FROM SRN FLORIDA TO NEAR 34N61W SANDWICHED BETWEEN THE UPPER TROUGH AND A SEPARATE UPPER LEVEL LOW NOW JUST S OF THE DOMINICAN REPUBLIC. A LARGE CLUSTER OF STRONG SHOWERS/THUNDERSTORMS IS N OF PUERTO RICO FROM 19N-20N BETWEEN 64W-67W NEAR THE NRN EXTENT OF A TROPICAL WAVE IN THE CARIBBEAN. FARTHER E...SURFACE RIDGING DOMINATES THE MAJORITY OF THE CENTRAL AND ERN TROPICAL ATLC CENTERED AROUND A 1025 MB HIGH NEAR 31N53W SUPPORTED BY AN UPPER LEVEL RIDGE CENTERED NEAR 14N55W. ANOTHER UPPER LEVEL LOW IS TO THE N NEAR 27N51W SUPPORTING A WEAK SURFACE LOW N OF THE DISCUSSION AREA. A LONGWAVE UPPER TROUGH IS OVER THE ERN ATLC N OF 23N ALONG 26W...WHILE AN UPPER RIDGE COVERS THE TROPICAL ATLC CENTERED OVER THE CAPE VERDE ISLANDS. A SAHARAN AIR LAYER CONSISTING OF DRY AND DUSTY AIR CONTINUES TO MOVE OVER THE ATLC MAINLY FROM 15N-24N FROM AFRICA TO THE ERN CARIBBEAN. FOR ADDITIONAL INFORMATION PLEASE VISIT HTTP://WWW.HURRICANES.GOV/MARINE $$ WALTON 000 AXNT20 KNHC 280550 TWDAT TROPICAL WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 205 AM EDT TUE JUN 28 2011 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. ...SPECIAL FEATURE... BROAD LOW PRESSURE CONTINUES TO COVER THE SRN GULF OF MEXICO WITH A 1006 MB SURFACE LOW LOCATED NEAR 19N92W...JUST E OF A TROPICAL WAVE ALONG 94W/95W. THE LOW CENTER IS NOT WELL DEFINED INDICATED BY A RECENT SCATTEROMETER PASS FROM 0352 UTC. HOWEVER...20-25 KT WINDS ARE INDICATED TO THE N OF THE LOW AND AROUND THE E SIDE OF THE TROPICAL WAVE. CURRENTLY A LARGE CLUSTER OF NUMEROUS CONVECTION IS E OF THE LOW CENTER OVER NRN GUATEMALA AND THE YUCATAN PENINSULA FROM 16N-20N BETWEEN 88W-91W...AND OVER THE NRN YUCATAN PENINSULA FROM 20N-22N BETWEEN 87W-89W. UPPER LEVEL WINDS ARE CURRENTLY NOT FAVORABLE FOR DEVELOPMENT...BUT COULD BECOME SO OVER THE NEXT COUPLE OF DAYS. REGARDLESS OF DEVELOPMENT...SIGNIFICANT MOISTURE WILL REMAIN OVER THE SRN GULF AND YUCATAN PENINSULA LIKELY SUPPORTING STRONG SHOWERS/THUNDERSTORMS ALONG WITH GUSTY WINDS AS THE SYSTEM DRIFTS WNW OVER THE NEXT 48 HOURS. ...TROPICAL WAVES... A TROPICAL WAVE IS ACROSS THE CENTRAL ATLC ALONG 14N38W TO 5N39W MOVING W NEAR 15 KT. A RECENT SCATTEROMETER PASS FROM 0026 UTC SHOWS CLEAR CUT CYCLONIC SURFACE FLOW IS ABOUT THE WAVE AXIS. THE WAVE IS EMBEDDED WITHIN A SURGE OF DEEP LAYER MOISTURE EVIDENT IN TOTAL PRECIPITABLE WATER IMAGERY. SCATTERED MODERATE/STRONG CONVECTION IS W OF THE WAVE AXIS FROM 9N-11N BETWEEN 41W-46W. A TROPICAL WAVE EXTENDS ACROSS WRN PUERTO RICO AND THE ERN CARIBBEAN FROM 20N66W TO 11N68W MOVING W NEAR 15 KT. THE WAVE LIES IN AN AREA OF MODERATE DEEP LAYER MOISTURE THAT IS ACROSS THE ERN CARIBBEAN. AN UPPER LEVEL LOW JUST S OF THE DOMINICAN REPUBLIC IS PROVIDING DIFFLUENCE ALOFT ABOVE THE WAVE AXIS. THIS COMBINATION IS CAUSING A CLUSTER OF STRONG CONVECTION NEAR THE NRN EXTENT OF THE WAVE FROM 19N-20N BETWEEN 64W-67W. MODERATE CONVECTION IS ALSO ACROSS MUCH OF THE DOMINICAN REPUBLIC AND NEAR THE WAVE AXIS FROM 14N-16N BETWEEN 66W-68W. POSSIBLE ISOLATED SHOWERS COVER THE REMAINDER OF THE AREA FROM 14N-21N BETWEEN 64W-72W. THE UPPER LOW IS FORECAST TO DRIFT SW AS THE WAVE MOVES W WHICH WILL CONTINUE TO PLACE THE WAVE UNDER DIFFLUENCE ALOFT. EXPECT CONTINUED SHOWER/THUNDERSTORM ACTIVITY OVER THE CENTRAL CARIBBEAN OVER THE NEXT 24 HOURS. A TROPICAL WAVE IS OVER THE SW GULF OF MEXICO IN THE BAY OF CAMPECHE ALONG 25N94W TO 17N95W DRIFTING WNW. THIS WAVE ALSO LIES UNDER THE DIFFLUENT SIDE OF AN UPPER LEVEL TROUGH OVER THE NW GULF WHICH IS HELPING ENHANCE CONVECTION. CLUSTERS OF NUMEROUS STRONG CONVECTION ARE OVER WRN MEXICO FROM 14N-19N BETWEEN 93W-95W. SCATTERED MODERATE/STRONG CONVECTION IS ALSO W OF THE WAVE AXIS FROM 15N-21N BETWEEN 95W-99W...AND NEAR THE WAVE AXIS FROM 22N-24N BETWEEN 92W-95W. A SURFACE LOW PRESSURE SYSTEM IS ALSO E OF THE WAVE AXIS NEAR THE COAST OF THE YUCATAN PENINSULA. THIS LOW...AS WELL AS THE CONVECTION OVER THE YUCATAN PENINSULA IS DESCRIBED IN THE SPECIAL FEATURES SECTION ABOVE. AT THIS TIME...THE WAVE IS EXPECTED TO STAY SEPARATE FROM THE LOW PRESSURE SYSTEM AND WILL MOVE INLAND OVER NE MEXICO AND DISSIPATE OVER THE NEXT 24 HOURS. ...ITCZ/MONSOON TROUGH... THE MONSOON TROUGH EXTENDS ACROSS AFRICA FROM THE PRIME MERIDIAN AT 23N ALONG 20N08W 16N15W TO 7N19W. THE ITCZ AXIS CONTINUES FROM 7N19W ALONG 7N31W 7N40W 5N57W. A LARGE BURST OF NUMEROUS STRONG CONVECTION IS MOVING OFF THE W AFRICAN COAST FROM 8N-16N BETWEEN 13W-17W...LIKELY ASSOCIATED WITH THE NEXT TROPICAL WAVE. ISOLATED MODERATE/STRONG CONVECTION IS FROM 7N-10N BETWEEN 18W-21W...AND WITHIN 100 NM S OF THE AXIS BETWEEN 28W-33W. SCATTERED MODERATE/STRONG CONVECTION IS N OF BRAZIL FROM EQ-6N BETWEEN 45W-50W. ...DISCUSSION... GULF OF MEXICO... BROAD LOW PRESSURE CONTINUES TO IMPACT MUCH OF THE SRN GULF OF MEXICO AS DISCUSSED IN THE SPECIAL FEATURE SECTION AND TROPICAL WAVE SECTION. MOIST SWLY FLOW ALOFT COVERS MUCH OF THE BASIN BETWEEN AN UPPER LEVEL TROUGH OVER THE NW GULF EXTENDING FROM SRN ALABAMA TO N CENTRAL MEXICO NEAR 22N100W...AND AN UPPER LEVEL RIDGE EXTENDING FROM THE NW CARIBBEAN AND ACROSS THE FLORIDA PENINSULA. THIS PATTERN IS ALSO CREATING A LARGE AREA OF DIFFLUENCE WHICH IS AIDING CONVECTION NEAR BOTH THE TROPICAL WAVE AND THE SURFACE LOW. SCATTERED SHOWERS/THUNDERSTORMS NOT ASSOCIATED WITH EITHER OF THOSE FEATURES ARE ALSO IN THE SE GULF FROM 23N-26N BETWEEN 81W-88W...WITH ISOLATED SHOWERS/THUNDERSTORMS ACROSS FLORIDA AND THE NE GULF. DRY AIR COVERS THE NW GULF BEHIND THE UPPER TROUGH PROVIDING FAIR WEATHER ACROSS THAT PORTION OF THE BASIN. AT THE SURFACE...WEAK SURFACE RIDING IS OVER THE NRN GULF ALONG 28N EXTENDING FROM THE W ATLC. EXPECT SIGNIFICANT MOISTURE TO REMAIN ACROSS THE AREA OVER THE NEXT SEVERAL DAYS WITH A HIGH CHANCE OF PRECIPITATION. CARIBBEAN SEA... PORTIONS OF THE WRN CARIBBEAN ARE FINALLY GETTING SOME RELIEF FROM THE MOISTURE THAT HAS NOW MOVED OVER THE GULF OF MEXICO. HOWEVER...SCATTERED SHOWERS/THUNDERSTORMS STILL REMAIN OVER CENTRAL AMERICA INCLUDING NICARAGUA...HONDURAS...GUATEMALA...AND BELIZE. MOST OF THE ACTIVITY OVER CUBA HAS NOW DIED DOWN LEAVING THE REMAINDER OF THE WRN CARIBBEAN W OF 72W UNDER MOSTLY FAIR CONDITIONS. ALOFT...DRY AIR IS BEING DRAWN OVER THE CENTRAL CARIBBEAN BETWEEN AN UPPER LEVEL RIDGE EXTENDING FROM THE NW CARIBBEAN TO FLORIDA...AND AN UPPER LEVEL LOW STILL SPINNING JUST S OF THE DOMINICAN REPUBLIC NEAR 17N70W. THE UPPER LOW IS INTERACTING WITH A TROPICAL WAVE BETWEEN 66W-68W. THIS IS SUPPORTING ISOLATED SHOWERS N OF 14N BETWEEN 64W-72W...WITH AREAS OF STRONGER ACTIVITY N OF PUERTO RICO AND OVER THE DOMINICAN REPUBLIC. EXPECT SHOWER ACTIVITY TO INCREASE OVER THE N CENTRAL CARIBBEAN AS THE UPPER LOW DRIFTS SW AND THE WAVE MOVES W. ATLANTIC OCEAN... AN UPPER LEVEL TROUGH CONTINUES TO SIT OVER THE NW ATLC SUPPORTING POSSIBLE ISOLATED SHOWERS ALONG A LINE FROM 28N79W TO 32N70W. AN UPPER LEVEL RIDGE IS TO THE E EXTENDING FROM SRN FLORIDA TO NEAR 34N61W SANDWICHED BETWEEN THE UPPER TROUGH AND A SEPARATE UPPER LEVEL LOW NOW JUST S OF THE DOMINICAN REPUBLIC. A LARGE CLUSTER OF STRONG SHOWERS/THUNDERSTORMS IS N OF PUERTO RICO FROM 19N-20N BETWEEN 64W-67W NEAR THE NRN EXTENT OF A TROPICAL WAVE IN THE CARIBBEAN. FARTHER E...SURFACE RIDGING DOMINATES THE MAJORITY OF THE CENTRAL AND ERN TROPICAL ATLC CENTERED AROUND A 1025 MB HIGH NEAR 31N53W SUPPORTED BY AN UPPER LEVEL RIDGE CENTERED NEAR 14N55W. ANOTHER UPPER LEVEL LOW IS TO THE N NEAR 27N51W SUPPORTING A WEAK SURFACE LOW N OF THE DISCUSSION AREA. A LONGWAVE UPPER TROUGH IS OVER THE ERN ATLC N OF 23N ALONG 26W...WHILE AN UPPER RIDGE COVERS THE TROPICAL ATLC CENTERED OVER THE CAPE VERDE ISLANDS. A SAHARAN AIR LAYER CONSISTING OF DRY AND DUSTY AIR CONTINUES TO MOVE OVER THE ATLC MAINLY FROM 15N-24N FROM AFRICA TO THE ERN CARIBBEAN. FOR ADDITIONAL INFORMATION PLEASE VISIT HTTP://WWW.HURRICANES.GOV/MARINE $$ WALTON