000 AXNT20 KNHC 281759 TWDAT TROPICAL WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 205 PM 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 1200 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 1715 UTC. ...SPECIAL FEATURES... BROAD LOW PRESSURE CONTINUES TO COVER THE SRN GULF OF MEXICO WITH A 1006 MB SURFACE LOW LOCATED NEAR 20N93W...JUST E OF A TROPICAL WAVE ALONG 96W. CURRENTLY A LARGE AREA OF NUMEROUS MODERATE/SCATTERED STRONG CONVECTION IS E OF THE LOW CENTER OVER THE YUCATAN PENINSULA FROM 19N-24N BETWEEN 86W-90W AND FROM 18N-22N BETWEEN 90W-94W. UPPER LEVEL WINDS ARE CURRENTLY NOT FAVORABLE FOR DEVELOPMENT...BUT COULD BECOME SO IN THE NEXT DAY OR TWO. REGARDLESS OF DEVELOPMENT...SIGNIFICANT MOISTURE WILL REMAIN OVER THE SRN GULF AND YUCATAN PENINSULA LIKELY SUPPORTING SHOWERS AND THUNDERSTORMS ALONG WITH FRESH/STRONG WINDS AS THE SYSTEM DRIFTS W-NW OVER THE NEXT 48 HOURS. ...TROPICAL WAVES... A TROPICAL WAVE IS ACROSS THE CENTRAL ATLC ALONG 13N41W TO 8N45W MOVING W NEAR 15 KT. VISIBLE SATELLITE IMAGERY SHOWS CLEAR LOW LEVEL CYCLONIC FLOW ABOUT THE WAVE AXIS. THE WAVE IS EMBEDDED WITHIN A SURGE OF DEEP LAYER MOISTURE EVIDENT IN TOTAL PRECIPITABLE WATER IMAGERY. SCATTERED MODERATE CONVECTION IS FROM 10N-12N BETWEEN 42W-45W AND WITHIN 45 NM EITHER SIDE OF THE WAVE AXIS S OF 9N. A TROPICAL WAVE EXTENDS ACROSS MONA PASSAGE INTO THE ERN CARIBBEAN FROM 14N-23N ALONG 68W MOVING W NEAR 15 KT. THE WAVE LIES IN AN AREA OF MODERATE DEEP LAYER MOISTURE THAT IS ACROSS THE ERN CARIBBEAN BETWEEN 64W-72W. 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 SCATTERED MODERATE/ISOLATED STRONG CONVECTION NEAR THE NRN EXTENT OF THE WAVE FROM 23N-24N BETWEEN 64W-68W. POSSIBLE ISOLATED SHOWERS COVER THE AREA FROM 15N-23N BETWEEN 65W-73W. THE UPPER LOW IS FORECAST TO DRIFT SW AS THE WAVE MOVES W-NW 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 FROM 19N-26N ALONG 96W DRIFTING W-NW. THIS WAVE ALSO LIES UNDER THE DIFFLUENT SIDE OF AN UPPER LEVEL TROUGH OVER THE NW GULF WHICH IS HELPING ENHANCE CONVECTION. AN AREA OF NUMEROUS STRONG CONVECTION IS OVER SRN MEXICO FROM 18N-19N BETWEEN 94W-95W. CLUSTERS OF SCATTERED MODERATE CONVECTION ARE FROM 18N-24N BETWEEN 94W-98W. A SURFACE LOW PRESSURE SYSTEM IS ALSO E OF THE WAVE AXIS OFF 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 INTO THE E TROPICAL ATLC FROM GUINEA BISSAU NEAR 11N16W TO 10N20W CONTINUING AS THE ITCZ AXIS ALONG 9N28W 3N44W 7N57W. SCATTERED MODERATE/ISOLATED STRONG CONVECTION IS MOVING OFF THE W AFRICAN COAST FROM 6N-13N BETWEEN 15W-23W...LIKELY ASSOCIATED WITH THE NEXT TROPICAL WAVE. SIMILAR CONVECTION IS N OF BRAZIL FROM THE EQUATOR TO 6N BETWEEN 48W-52W AND CLUSTERS FROM 8N-11N BETWEEN 48W-60W. ...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 AND AN UPPER LEVEL RIDGE EXTENDING FROM THE YUCATAN PENINSULA AND ACROSS THE FLORIDA PENINSULA INTO THE W ATLC. THIS PATTERN IS ALSO CREATING A LARGE AREA OF DIFFLUENCE ALOFT WHICH IS AIDING CONVECTION NEAR BOTH THE TROPICAL WAVE AND THE SURFACE LOW. SCATTERED SHOWERS AND THUNDERSTORMS NOT ASSOCIATED WITH EITHER OF THOSE FEATURES ARE ALSO IN THE SE GULF FROM 24N-29N BETWEEN 80W-87W...WITH POSSIBLE 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 RIDGING IS OVER THE NE GULF EXTENDING FROM THE W ATLC AND SUPPORTED BY A 1020 MB HIGH OVER THE N FLORIDA PENINSULA NEAR 29N82W. EXPECT SIGNIFICANT MOISTURE TO REMAIN ACROSS THE AREA OVER THE NEXT SEVERAL DAYS WITH A HIGH CHANCE OF PRECIPITATION. CARIBBEAN SEA... MUCH OF THE WRN CARIBBEAN IS EXPERIENCING FAIR WEATHER AS HIGH MOISTURE VALUES HAVE NOW SHIFTED NW INTO THE SRN GULF OF MEXICO. HOWEVER...SCATTERED SHOWERS STILL REMAIN IN THE SW CARIBBEAN SW OF A LINE FROM 13N83W TO 9N77W AND INLAND OVER PANAMA AND COSTA RICA. SCATTERED SHOWERS AND THUNDERSTORMS ARE INLAND OVER NICARAGUA AND HONDURAS. ALOFT...DRY AIR IS BEING DRAWN OVER THE CENTRAL CARIBBEAN BETWEEN AN UPPER LEVEL RIDGE EXTENDING FROM THE YUCATAN PENINSULA TO FLORIDA...AND AN UPPER LEVEL LOW STILL SPINNING JUST S OF THE DOMINICAN REPUBLIC NEAR 17N72W. THE UPPER LOW IS INTERACTING WITH A TROPICAL WAVE OVER THE MONA PASSAGE. THIS IS SUPPORTING ISOLATED SHOWERS N OF 15N BETWEEN 67W-73W. A LINE OF SHOWERS AND POSSIBLE THUNDERSTORMS IS MOVING INTO THE E CARIBBEAN ACROSS THE WINDWARD ISLANDS AND IS FROM 12N-14N BETWEEN 60W-65W. EXPECT SHOWER ACTIVITY TO CONTINUE OVER THE N CENTRAL CARIBBEAN AS THE UPPER LOW DRIFTS SW AND THE WAVE MOVES W-NW. ATLANTIC OCEAN... AN UPPER LEVEL TROUGH CONTINUES TO SIT OVER THE NW ATLC SUPPORTING ISOLATED SHOWERS NW OF A LINE FROM 24N80W TO 32N68W. AN UPPER LEVEL RIDGE EXTENDS FROM SRN FLORIDA TO NEAR 34N61W. AN UPPER LEVEL LOW JUST S OF THE DOMINICAN REPUBLIC IS INTERACTING WITH A TROPICAL WAVE SUPPORTING A CLUSTER OF SHOWERS/THUNDERSTORMS N OF PUERTO RICO FROM 23N-24N BETWEEN 64W-68W. SURFACE RIDGING DOMINATES THE MAJORITY OF THE TROPICAL ATLC CENTERED AROUND A 1025 MB HIGH NEAR 32N50W SUPPORTED BY AN UPPER LEVEL RIDGE CENTERED NEAR 31N42W. A WEAK SURFACE TROUGH IS FROM 26N54W TO 29N53W INTERSECTING THE SURFACE RIDGE WITH POSSIBLE ISOLATED SHOWERS WITHIN 75 NM OF THE AXIS. ANOTHER UPPER LEVEL LOW IS NEAR 26N51W SUPPORTING A WEAK SURFACE LOW N OF THE DISCUSSION AREA. A SURFACE TROUGH EXTENDS FROM THE SURFACE LOW INTO THE AREA ALONG 32N40W TO 28N45W. POSSIBLE ISOLATED SHOWERS ARE ALONG THE TROUGH AXIS. A LONGWAVE UPPER TROUGH IS OVER THE ERN ATLC N OF 25N E OF 34W...WHILE AN UPPER RIDGE COVERS THE TROPICAL ATLC CENTERED JUST W OF THE CAPE VERDE ISLANDS. A SAHARAN AIR LAYER CONSISTING OF DRY AND DUSTY AIR CONTINUES TO MOVE OVER THE ATLC MAINLY FROM 12N-22N BETWEEN THE W AFRICA COAST TO THE ERN CARIBBEAN SEA. FOR ADDITIONAL INFORMATION PLEASE VISIT HTTP://WWW.HURRICANES.GOV/MARINE $$ MONTALVO/HUFFMAN 000 AXNT20 KNHC 281759 TWDAT TROPICAL WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 205 PM 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 1200 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 1715 UTC. ...SPECIAL FEATURES... BROAD LOW PRESSURE CONTINUES TO COVER THE SRN GULF OF MEXICO WITH A 1006 MB SURFACE LOW LOCATED NEAR 20N93W...JUST E OF A TROPICAL WAVE ALONG 96W. CURRENTLY A LARGE AREA OF NUMEROUS MODERATE/SCATTERED STRONG CONVECTION IS E OF THE LOW CENTER OVER THE YUCATAN PENINSULA FROM 19N-24N BETWEEN 86W-90W AND FROM 18N-22N BETWEEN 90W-94W. UPPER LEVEL WINDS ARE CURRENTLY NOT FAVORABLE FOR DEVELOPMENT...BUT COULD BECOME SO IN THE NEXT DAY OR TWO. REGARDLESS OF DEVELOPMENT...SIGNIFICANT MOISTURE WILL REMAIN OVER THE SRN GULF AND YUCATAN PENINSULA LIKELY SUPPORTING SHOWERS AND THUNDERSTORMS ALONG WITH FRESH/STRONG WINDS AS THE SYSTEM DRIFTS W-NW OVER THE NEXT 48 HOURS. ...TROPICAL WAVES... A TROPICAL WAVE IS ACROSS THE CENTRAL ATLC ALONG 13N41W TO 8N45W MOVING W NEAR 15 KT. VISIBLE SATELLITE IMAGERY SHOWS CLEAR LOW LEVEL CYCLONIC FLOW ABOUT THE WAVE AXIS. THE WAVE IS EMBEDDED WITHIN A SURGE OF DEEP LAYER MOISTURE EVIDENT IN TOTAL PRECIPITABLE WATER IMAGERY. SCATTERED MODERATE CONVECTION IS FROM 10N-12N BETWEEN 42W-45W AND WITHIN 45 NM EITHER SIDE OF THE WAVE AXIS S OF 9N. A TROPICAL WAVE EXTENDS ACROSS MONA PASSAGE INTO THE ERN CARIBBEAN FROM 14N-23N ALONG 68W MOVING W NEAR 15 KT. THE WAVE LIES IN AN AREA OF MODERATE DEEP LAYER MOISTURE THAT IS ACROSS THE ERN CARIBBEAN BETWEEN 64W-72W. 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 SCATTERED MODERATE/ISOLATED STRONG CONVECTION NEAR THE NRN EXTENT OF THE WAVE FROM 23N-24N BETWEEN 64W-68W. POSSIBLE ISOLATED SHOWERS COVER THE AREA FROM 15N-23N BETWEEN 65W-73W. THE UPPER LOW IS FORECAST TO DRIFT SW AS THE WAVE MOVES W-NW 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 FROM 19N-26N ALONG 96W DRIFTING W-NW. THIS WAVE ALSO LIES UNDER THE DIFFLUENT SIDE OF AN UPPER LEVEL TROUGH OVER THE NW GULF WHICH IS HELPING ENHANCE CONVECTION. AN AREA OF NUMEROUS STRONG CONVECTION IS OVER SRN MEXICO FROM 18N-19N BETWEEN 94W-95W. CLUSTERS OF SCATTERED MODERATE CONVECTION ARE FROM 18N-24N BETWEEN 94W-98W. A SURFACE LOW PRESSURE SYSTEM IS ALSO E OF THE WAVE AXIS OFF 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 INTO THE E TROPICAL ATLC FROM GUINEA BISSAU NEAR 11N16W TO 10N20W CONTINUING AS THE ITCZ AXIS ALONG 9N28W 3N44W 7N57W. SCATTERED MODERATE/ISOLATED STRONG CONVECTION IS MOVING OFF THE W AFRICAN COAST FROM 6N-13N BETWEEN 15W-23W...LIKELY ASSOCIATED WITH THE NEXT TROPICAL WAVE. SIMILAR CONVECTION IS N OF BRAZIL FROM THE EQUATOR TO 6N BETWEEN 48W-52W AND CLUSTERS FROM 8N-11N BETWEEN 48W-60W. ...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 AND AN UPPER LEVEL RIDGE EXTENDING FROM THE YUCATAN PENINSULA AND ACROSS THE FLORIDA PENINSULA INTO THE W ATLC. THIS PATTERN IS ALSO CREATING A LARGE AREA OF DIFFLUENCE ALOFT WHICH IS AIDING CONVECTION NEAR BOTH THE TROPICAL WAVE AND THE SURFACE LOW. SCATTERED SHOWERS AND THUNDERSTORMS NOT ASSOCIATED WITH EITHER OF THOSE FEATURES ARE ALSO IN THE SE GULF FROM 24N-29N BETWEEN 80W-87W...WITH POSSIBLE 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 RIDGING IS OVER THE NE GULF EXTENDING FROM THE W ATLC AND SUPPORTED BY A 1020 MB HIGH OVER THE N FLORIDA PENINSULA NEAR 29N82W. EXPECT SIGNIFICANT MOISTURE TO REMAIN ACROSS THE AREA OVER THE NEXT SEVERAL DAYS WITH A HIGH CHANCE OF PRECIPITATION. CARIBBEAN SEA... MUCH OF THE WRN CARIBBEAN IS EXPERIENCING FAIR WEATHER AS HIGH MOISTURE VALUES HAVE NOW SHIFTED NW INTO THE SRN GULF OF MEXICO. HOWEVER...SCATTERED SHOWERS STILL REMAIN IN THE SW CARIBBEAN SW OF A LINE FROM 13N83W TO 9N77W AND INLAND OVER PANAMA AND COSTA RICA. SCATTERED SHOWERS AND THUNDERSTORMS ARE INLAND OVER NICARAGUA AND HONDURAS. ALOFT...DRY AIR IS BEING DRAWN OVER THE CENTRAL CARIBBEAN BETWEEN AN UPPER LEVEL RIDGE EXTENDING FROM THE YUCATAN PENINSULA TO FLORIDA...AND AN UPPER LEVEL LOW STILL SPINNING JUST S OF THE DOMINICAN REPUBLIC NEAR 17N72W. THE UPPER LOW IS INTERACTING WITH A TROPICAL WAVE OVER THE MONA PASSAGE. THIS IS SUPPORTING ISOLATED SHOWERS N OF 15N BETWEEN 67W-73W. A LINE OF SHOWERS AND POSSIBLE THUNDERSTORMS IS MOVING INTO THE E CARIBBEAN ACROSS THE WINDWARD ISLANDS AND IS FROM 12N-14N BETWEEN 60W-65W. EXPECT SHOWER ACTIVITY TO CONTINUE OVER THE N CENTRAL CARIBBEAN AS THE UPPER LOW DRIFTS SW AND THE WAVE MOVES W-NW. ATLANTIC OCEAN... AN UPPER LEVEL TROUGH CONTINUES TO SIT OVER THE NW ATLC SUPPORTING ISOLATED SHOWERS NW OF A LINE FROM 24N80W TO 32N68W. AN UPPER LEVEL RIDGE EXTENDS FROM SRN FLORIDA TO NEAR 34N61W. AN UPPER LEVEL LOW JUST S OF THE DOMINICAN REPUBLIC IS INTERACTING WITH A TROPICAL WAVE SUPPORTING A CLUSTER OF SHOWERS/THUNDERSTORMS N OF PUERTO RICO FROM 23N-24N BETWEEN 64W-68W. SURFACE RIDGING DOMINATES THE MAJORITY OF THE TROPICAL ATLC CENTERED AROUND A 1025 MB HIGH NEAR 32N50W SUPPORTED BY AN UPPER LEVEL RIDGE CENTERED NEAR 31N42W. A WEAK SURFACE TROUGH IS FROM 26N54W TO 29N53W INTERSECTING THE SURFACE RIDGE WITH POSSIBLE ISOLATED SHOWERS WITHIN 75 NM OF THE AXIS. ANOTHER UPPER LEVEL LOW IS NEAR 26N51W SUPPORTING A WEAK SURFACE LOW N OF THE DISCUSSION AREA. A SURFACE TROUGH EXTENDS FROM THE SURFACE LOW INTO THE AREA ALONG 32N40W TO 28N45W. POSSIBLE ISOLATED SHOWERS ARE ALONG THE TROUGH AXIS. A LONGWAVE UPPER TROUGH IS OVER THE ERN ATLC N OF 25N E OF 34W...WHILE AN UPPER RIDGE COVERS THE TROPICAL ATLC CENTERED JUST W OF THE CAPE VERDE ISLANDS. A SAHARAN AIR LAYER CONSISTING OF DRY AND DUSTY AIR CONTINUES TO MOVE OVER THE ATLC MAINLY FROM 12N-22N BETWEEN THE W AFRICA COAST TO THE ERN CARIBBEAN SEA. FOR ADDITIONAL INFORMATION PLEASE VISIT HTTP://WWW.HURRICANES.GOV/MARINE $$ MONTALVO/HUFFMAN