000 AXNT20 KNHC 281151 TWDAT TROPICAL WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 805 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 0600 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 1115 UTC. ...SPECIAL FEATURE... BROAD LOW PRESSURE CONTINUES TO COVER THE SRN GULF OF MEXICO WITH A 1007 MB SURFACE LOW LOCATED NEAR 20N93W...JUST E OF A TROPICAL WAVE ALONG 94W/95W. CURRENTLY A LARGE AREA OF NUMEROUS MODERATE/SCATTERED STRONG CONVECTION IS E OF THE LOW CENTER OVER THE YUCATAN PENINSULA FROM 18N-22N BETWEEN 86W-93W. 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 14N40W TO 6N42W MOVING W NEAR 15 KT. THE FIRST VISIBLE SATELLITE IMAGES OF THE DAY SHOW 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/ISOLATED STRONG CONVECTION IS W OF THE WAVE AXIS FROM 9N-11N BETWEEN 42W-46W. A TROPICAL WAVE EXTENDS ACROSS MONA PASSAGE INTO THE ERN CARIBBEAN FROM 21N67W TO 14N69W MOVING W NEAR 15 KT. THE WAVE LIES IN AN AREA OF MODERATE DEEP LAYER MOISTURE THAT IS ACROSS THE ERN CARIBBEAN BETWEEN 65W-72W. AN UPPER LEVEL LOW JUST S OF THE DOMINICAN REPUBLIC IS PROVIDING DIFFLUENCE ALOFT ABOVE THE WAVE AXIS. THIS COMBINATION IS CAUSING A LARGE CLUSTER OF STRONG CONVECTION NEAR THE NRN EXTENT OF THE WAVE FROM 20N-22N BETWEEN 65W-68W. POSSIBLE ISOLATED SHOWERS COVER THE AREA FROM 14N-20N BETWEEN 67W-73W. 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 SRN MEXICO FROM 13N-17N BETWEEN 93W-96W. SCATTERED MODERATE/STRONG CONVECTION IS ALSO W OF THE WAVE AXIS FROM 18N-22N BETWEEN 95W-99W. SCATTERED MODERATE CONVECTION IS E OF THE WAVE AXIS FROM 22N-25N BETWEEN 93W-95W. 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 FROM THE PRIME MERIDIAN AT 19N ALONG 21N13W 13N17W 9N22W. THE ITCZ AXIS CONTINUES FROM 9N22W ALONG 6N33W 6N41W 2N52W. NUMEROUS MODERATE/SCATTERED STRONG CONVECTION IS MOVING OFF THE W AFRICAN COAST FROM 6N-13N BETWEEN 10W-18W...LIKELY ASSOCIATED WITH THE NEXT TROPICAL WAVE. SIMILAR CONVECTION IS N OF BRAZIL FROM EQ-6N BETWEEN 46W-51W. ...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 MISSISSIPPI TO N CENTRAL MEXICO NEAR 23N101W...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/THUNDERSTORMS NOT ASSOCIATED WITH EITHER OF THOSE FEATURES ARE ALSO IN THE SE GULF FROM 23N-27N 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 RIDING IS OVER THE NE GULF ALONG 29N 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... 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/THUNDERSTORMS STILL REMAIN IN THE SW CARIBBEAN S OF 15N BETWEEN 80W-84W...AND N OF HONDURAS FROM 16N-21N W OF 84W. 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 17N70W. THE UPPER LOW IS INTERACTING WITH A TROPICAL WAVE OVER THE MONA PASSAGE. THIS IS SUPPORTING ISOLATED SHOWERS N OF 14N BETWEEN 67W-73W...WITH AREAS OF STRONGER ACTIVITY N OF PUERTO RICO. EXPECT SHOWER ACTIVITY TO CONTINUE 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 28N81W TO 32N72W. AN UPPER LEVEL RIDGE IS TO THE E EXTENDING FROM SRN FLORIDA TO NEAR 33N62W. AN UPPER LEVEL LOW JUST S OF THE DOMINICAN REPUBLIC IS INTERACTING WITH A TROPICAL SUPPORTING A LARGE CLUSTER OF STRONG SHOWERS/THUNDERSTORMS N OF PUERTO RICO FROM 20N-22N BETWEEN 65W-68W. FARTHER E...SURFACE RIDGING DOMINATES THE MAJORITY OF THE CENTRAL AND ERN TROPICAL ATLC CENTERED AROUND A 1025 MB HIGH NEAR 31N54W SUPPORTED BY AN UPPER LEVEL RIDGE CENTERED NEAR 15N55W. ANOTHER UPPER LEVEL LOW IS TO THE N NEAR 26N50W SUPPORTING A WEAK SURFACE LOW N OF THE DISCUSSION AREA. A SURFACE TROUGH EXTENDS FROM THE SURFACE LOW INTO THE AREA ALONG 32N40W TO 28N44W. POSSIBLE ISOLATED SHOWERS ARE ALONG THE TROUGH AXIS. A LONGWAVE UPPER TROUGH IS OVER THE ERN ATLC N OF 20N ALONG 21W...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 15N-24N FROM AFRICA TO THE ERN CARIBBEAN. FOR ADDITIONAL INFORMATION PLEASE VISIT HTTP://WWW.HURRICANES.GOV/MARINE $$ WALTON 000 AXNT20 KNHC 281151 TWDAT TROPICAL WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 805 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 0600 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 1115 UTC. ...SPECIAL FEATURE... BROAD LOW PRESSURE CONTINUES TO COVER THE SRN GULF OF MEXICO WITH A 1007 MB SURFACE LOW LOCATED NEAR 20N93W...JUST E OF A TROPICAL WAVE ALONG 94W/95W. CURRENTLY A LARGE AREA OF NUMEROUS MODERATE/SCATTERED STRONG CONVECTION IS E OF THE LOW CENTER OVER THE YUCATAN PENINSULA FROM 18N-22N BETWEEN 86W-93W. 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 14N40W TO 6N42W MOVING W NEAR 15 KT. THE FIRST VISIBLE SATELLITE IMAGES OF THE DAY SHOW 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/ISOLATED STRONG CONVECTION IS W OF THE WAVE AXIS FROM 9N-11N BETWEEN 42W-46W. A TROPICAL WAVE EXTENDS ACROSS MONA PASSAGE INTO THE ERN CARIBBEAN FROM 21N67W TO 14N69W MOVING W NEAR 15 KT. THE WAVE LIES IN AN AREA OF MODERATE DEEP LAYER MOISTURE THAT IS ACROSS THE ERN CARIBBEAN BETWEEN 65W-72W. AN UPPER LEVEL LOW JUST S OF THE DOMINICAN REPUBLIC IS PROVIDING DIFFLUENCE ALOFT ABOVE THE WAVE AXIS. THIS COMBINATION IS CAUSING A LARGE CLUSTER OF STRONG CONVECTION NEAR THE NRN EXTENT OF THE WAVE FROM 20N-22N BETWEEN 65W-68W. POSSIBLE ISOLATED SHOWERS COVER THE AREA FROM 14N-20N BETWEEN 67W-73W. 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 SRN MEXICO FROM 13N-17N BETWEEN 93W-96W. SCATTERED MODERATE/STRONG CONVECTION IS ALSO W OF THE WAVE AXIS FROM 18N-22N BETWEEN 95W-99W. SCATTERED MODERATE CONVECTION IS E OF THE WAVE AXIS FROM 22N-25N BETWEEN 93W-95W. 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 FROM THE PRIME MERIDIAN AT 19N ALONG 21N13W 13N17W 9N22W. THE ITCZ AXIS CONTINUES FROM 9N22W ALONG 6N33W 6N41W 2N52W. NUMEROUS MODERATE/SCATTERED STRONG CONVECTION IS MOVING OFF THE W AFRICAN COAST FROM 6N-13N BETWEEN 10W-18W...LIKELY ASSOCIATED WITH THE NEXT TROPICAL WAVE. SIMILAR CONVECTION IS N OF BRAZIL FROM EQ-6N BETWEEN 46W-51W. ...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 MISSISSIPPI TO N CENTRAL MEXICO NEAR 23N101W...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/THUNDERSTORMS NOT ASSOCIATED WITH EITHER OF THOSE FEATURES ARE ALSO IN THE SE GULF FROM 23N-27N 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 RIDING IS OVER THE NE GULF ALONG 29N 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... 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/THUNDERSTORMS STILL REMAIN IN THE SW CARIBBEAN S OF 15N BETWEEN 80W-84W...AND N OF HONDURAS FROM 16N-21N W OF 84W. 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 17N70W. THE UPPER LOW IS INTERACTING WITH A TROPICAL WAVE OVER THE MONA PASSAGE. THIS IS SUPPORTING ISOLATED SHOWERS N OF 14N BETWEEN 67W-73W...WITH AREAS OF STRONGER ACTIVITY N OF PUERTO RICO. EXPECT SHOWER ACTIVITY TO CONTINUE 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 28N81W TO 32N72W. AN UPPER LEVEL RIDGE IS TO THE E EXTENDING FROM SRN FLORIDA TO NEAR 33N62W. AN UPPER LEVEL LOW JUST S OF THE DOMINICAN REPUBLIC IS INTERACTING WITH A TROPICAL SUPPORTING A LARGE CLUSTER OF STRONG SHOWERS/THUNDERSTORMS N OF PUERTO RICO FROM 20N-22N BETWEEN 65W-68W. FARTHER E...SURFACE RIDGING DOMINATES THE MAJORITY OF THE CENTRAL AND ERN TROPICAL ATLC CENTERED AROUND A 1025 MB HIGH NEAR 31N54W SUPPORTED BY AN UPPER LEVEL RIDGE CENTERED NEAR 15N55W. ANOTHER UPPER LEVEL LOW IS TO THE N NEAR 26N50W SUPPORTING A WEAK SURFACE LOW N OF THE DISCUSSION AREA. A SURFACE TROUGH EXTENDS FROM THE SURFACE LOW INTO THE AREA ALONG 32N40W TO 28N44W. POSSIBLE ISOLATED SHOWERS ARE ALONG THE TROUGH AXIS. A LONGWAVE UPPER TROUGH IS OVER THE ERN ATLC N OF 20N ALONG 21W...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 15N-24N FROM AFRICA TO THE ERN CARIBBEAN. FOR ADDITIONAL INFORMATION PLEASE VISIT HTTP://WWW.HURRICANES.GOV/MARINE $$ WALTON