000 AXNT20 KNHC 110549 TWDAT TROPICAL WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 205 AM EDT MON JUL 11 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 0500 UTC. ...TROPICAL WAVES... TROPICAL WAVE IN THE CENTRAL TRPCL ATLC EXTENDS FROM NEAR 14N47W TO 6N53W MOVING W 15-20 KT. WAVE CONTINUES TO PRECEDE A SURGE OF DEEP LAYER MOISTURE EVIDENT IN TOTAL PRECIPITABLE WATER IMAGERY. SATELLITE IMAGERY ALSO INDICATES LOW LEVEL CYCLONIC FLOW IS AROUND THE WAVE AXIS CONFIRMED BY AN ASCAT SCATTEROMETER PASS FROM 0100 UTC. SCATTERED MODERATE/ISOLATED STRONG CONVECTION IS WITHIN 120 NM W OF THE AXIS. TROPICAL WAVE IN THE CENTRAL/WRN CARIBBEAN EXTENDS ACROSS THE FAR WRN SIDE OF JAMAICA FROM 19N78W TO 11N79W MOVING W NEAR 15 KT. WAVE LIES WITHIN A BROAD AREA OF ENHANCED MOISTURE ACROSS THE WRN CARIBBEAN...AND JUST W OF THE HIGHEST MOISTURE VALUES IN THE AREA. THE WAVE LIES UNDER MOIST SWLY AND DIFFLUENT FLOW ALOFT WHICH IS HELPING ENHANCE SCATTERED MODERATE/ISOLATED STRONG CONVECTION W OF THE WAVE AXIS FROM 12N-19N BETWEEN 77W-84W. TROPICAL WAVE IN THE BAY OF CAMPECHE EXTENDS FROM 23N94W TO 14N95W MOVING W NEAR 10 KT. WAVE IS EMBEDDED WITHIN AN AREA OF ENHANCED MOISTURE PRESENT ACROSS THE WRN GULF OF MEXICO. WATER VAPOR IMAGERY INDICATES DRY AIR IN THE MID AND UPPER LEVELS IS BEING DRAWN AROUND THE SRN EXTENT OF AN UPPER LEVEL RIDGE OVER THE ERN GULF WHICH IS INHIBITING CONVECTION NEAR THE WAVE AXIS BESIDES AN AREA OF STRONG CONVECTION OVER MEXICO FROM 15N-18N BETWEEN 92W-97W. ...THE ITCZ/THE MONSOON TROUGH... THE MONSOON TROUGH EXTENDS ACROSS AFRICA FROM THE PRIME MERIDIAN AT 23N ALONG 21N8W 18N17W 12N20W 10N28W. THE ITCZ CONTINUES FROM 10N28W ALONG 10N47W 8N63W. SCATTERED MODERATE/ISOLATED STRONG CONVECTION IS FROM 7N-10N BETWEEN 15W-23W. SIMILAR ACTIVITY IS FROM 8N-10N BETWEEN 41W-43W...AND FROM 7N-9N BETWEEN 54W-56W. ...DISCUSSION... GULF OF MEXICO... A TROPICAL WAVE IN THE SRN BAY OF CAMPECHE IS CAUSING AN AREA OF CONVECTION OVER SRN MEXICO. SEE TROPICAL WAVE SECTION ABOVE FOR MORE DETAILS. THE REMAINDER OF THE BASIN IS DOMINATED BY SURFACE RIDGING AROUND A 1017 MB HIGH OFF THE NW COAST OF FLORIDA NEAR 28N85W. THIS RIDGE IS SUPPORTED BY AN UPPER LEVEL RIDGE CENTERED OVER CENTRAL ALABAMA. AN UPPER LEVEL TROUGH COVERS THE FAR WRN GULF CENTERED OVER NRN TEXAS. DRY AIR IS WRAPPING AROUND THE SRN EXTENT OF THE UPPER RIDGE ACROSS THE FLORIDA STRAITS AND INTO THE CENTRAL GULF WHICH IS SUPPORTING FAIR WEATHER ACROSS MUCH OF THE BASIN. HOWEVER...A SHORTWAVE UPPER LEVEL TROUGH PERTURBS INTO THE UPPER RIDGE FROM THE W ATLC AND ACROSS NRN FLORIDA. THIS TROUGH COMBINED WITH THE EFFECTS OF ENHANCED MOISTURE IS CURRENTLY ENHANCING AN AREA OF STRONG SHOWERS AND THUNDERSTORMS ACROSS SW FLORIDA FROM LAKE OKEECHOBEE TO BETWEEN SARASOTA AND FORT MYERS. A FEW ISOLATED SHOWERS ARE ELSEWHERE WITHIN 120 NM OF THE W FLORIDA COAST N OF 25N. EXPECT THE TROPICAL WAVE TO MOVE WWD TOWARDS MEXICO AS WEAK SURFACE RIDGING CONTINUES ACROSS THE REMAINDER OF THE BASIN. CARIBBEAN SEA... A WEAK SURFACE TROUGH EXTENDS ACROSS WRN CUBA...BUT CURRENTLY NOT CAUSING ANY ACTIVE WEATHER DUE TO DRY AIR WRAPPING AROUND THE SRN END OF AN UPPER LEVEL RIDGE OVER THE ERN GULF. AN UPPER LEVEL TROUGH COVERS THE NW CARIBBEAN CENTERED NEAR 18N82W. AN UPPER LEVEL RIDGE COVERS THE CENTRAL CARIBBEAN CENTERED N OF VENEZUELA. THIS PATTERN IS CREATING MOIST SWLY FLOW ALOFT FROM COSTA RICA TO THE WINDWARD PASSAGE. THIS AREA OF DIFFLUENCE IS ALSO ABOVE A TROPICAL WAVE ACROSS WRN JAMAICA. THIS COMBINATION IS SUPPORTING SCATTERED SHOWERS/THUNDERSTORMS FROM 11N-20N BETWEEN 76W-86W. SIMILAR ACTIVITY IS S OF 11N ACROSS COSTA RICA AND PANAMA INFLUENCED BY THE MONSOON TROUGH THAT EXTENDS FROM THE E PACIFIC ACROSS COSTA RICA TO NRN COLOMBIA. MODEL GUIDANCE STILL INDICATES THAT THE MONSOON TROUGH WILL BEGIN TO LIFT N LATER IN THE WEEK ACROSS SRN MEXICO AND THE NRN CENTRAL CARIBBEAN WHICH WILL CONCENTRATE SHOWER ACTIVITY OVER THESE AREAS. THE ERN CARIBBEAN IS UNDER MOSTLY FAIR CONDITIONS IN ELY 20-25 KT TRADEWINDS. A FEW EMBEDDED SHOWERS ARE EMBEDDED IN THE ELY FLOW ACROSS THE NE CARIBBEAN WITH A CLUSTER OF THUNDERSTORMS CURRENTLY OVER THE MONA PASSAGE. A TROPICAL WAVE E OF THE LESSER ANTILLES IS EXPECTED TO IMPACT THE BASIN LATER IN THE WEEK. ATLANTIC OCEAN... WEAK SURFACE RIDGING DOMINATES THE WRN ATLC MAINTAINING MOSTLY FAIR CONDITIONS. THE RIDGE IS SUPPORTED BY AN UPPER LEVEL RIDGE CENTERED OVER CENTRAL ALABAMA WITH ANTICYCLONIC CIRCULATION EXTENDING TO 60W. HOWEVER...A SHORTWAVE UPPER TROUGH EXTENDS INTO THE UPPER RIDGE ALONG 37N58W 31N72W 29N82W. THIS UPPER TROUGH IS SUPPORTING AN AREA OF ISOLATED SHOWERS/POSSIBLE THUNDERSTORMS N OF 29N BETWEEN 60W-78W. AN UPPER LEVEL LOW IS SPINNING IN THE CENTRAL ATLC NEAR 30N55W SUPPORTING A SURFACE TROUGH ALONG 31N55W TO 25N58W. SCATTERED SHOWERS ARE WITHIN 120 NM E OF THE AXIS. THE REMAINDER OF THE BASIN IS DOMINATED BY SURFACE RIDGING AROUND A 1029 MB HIGH NEAR 35N36W PROVIDING FAIR WEATHER. ALOFT...AN UPPER LEVEL RIDGE COVERS THE MAJORITY OF THE ERN ATLC CENTERED SW OF THE AZORES ISLANDS. A NARROW UPPER LEVEL TROUGH EXTENDS FROM THE CANARY ISLANDS TO JUST N OF THE CAPE VERDE ISLANDS CAUSING NO ACTIVITY WEATHER IN THE DISCUSSION AREA. FOR ADDITIONAL INFORMATION PLEASE VISIT HTTP://WWW.HURRICANES.GOV/MARINE $$ WALTON 000 AXNT20 KNHC 110549 TWDAT TROPICAL WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 205 AM EDT MON JUL 11 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 0500 UTC. ...TROPICAL WAVES... TROPICAL WAVE IN THE CENTRAL TRPCL ATLC EXTENDS FROM NEAR 14N47W TO 6N53W MOVING W 15-20 KT. WAVE CONTINUES TO PRECEDE A SURGE OF DEEP LAYER MOISTURE EVIDENT IN TOTAL PRECIPITABLE WATER IMAGERY. SATELLITE IMAGERY ALSO INDICATES LOW LEVEL CYCLONIC FLOW IS AROUND THE WAVE AXIS CONFIRMED BY AN ASCAT SCATTEROMETER PASS FROM 0100 UTC. SCATTERED MODERATE/ISOLATED STRONG CONVECTION IS WITHIN 120 NM W OF THE AXIS. TROPICAL WAVE IN THE CENTRAL/WRN CARIBBEAN EXTENDS ACROSS THE FAR WRN SIDE OF JAMAICA FROM 19N78W TO 11N79W MOVING W NEAR 15 KT. WAVE LIES WITHIN A BROAD AREA OF ENHANCED MOISTURE ACROSS THE WRN CARIBBEAN...AND JUST W OF THE HIGHEST MOISTURE VALUES IN THE AREA. THE WAVE LIES UNDER MOIST SWLY AND DIFFLUENT FLOW ALOFT WHICH IS HELPING ENHANCE SCATTERED MODERATE/ISOLATED STRONG CONVECTION W OF THE WAVE AXIS FROM 12N-19N BETWEEN 77W-84W. TROPICAL WAVE IN THE BAY OF CAMPECHE EXTENDS FROM 23N94W TO 14N95W MOVING W NEAR 10 KT. WAVE IS EMBEDDED WITHIN AN AREA OF ENHANCED MOISTURE PRESENT ACROSS THE WRN GULF OF MEXICO. WATER VAPOR IMAGERY INDICATES DRY AIR IN THE MID AND UPPER LEVELS IS BEING DRAWN AROUND THE SRN EXTENT OF AN UPPER LEVEL RIDGE OVER THE ERN GULF WHICH IS INHIBITING CONVECTION NEAR THE WAVE AXIS BESIDES AN AREA OF STRONG CONVECTION OVER MEXICO FROM 15N-18N BETWEEN 92W-97W. ...THE ITCZ/THE MONSOON TROUGH... THE MONSOON TROUGH EXTENDS ACROSS AFRICA FROM THE PRIME MERIDIAN AT 23N ALONG 21N8W 18N17W 12N20W 10N28W. THE ITCZ CONTINUES FROM 10N28W ALONG 10N47W 8N63W. SCATTERED MODERATE/ISOLATED STRONG CONVECTION IS FROM 7N-10N BETWEEN 15W-23W. SIMILAR ACTIVITY IS FROM 8N-10N BETWEEN 41W-43W...AND FROM 7N-9N BETWEEN 54W-56W. ...DISCUSSION... GULF OF MEXICO... A TROPICAL WAVE IN THE SRN BAY OF CAMPECHE IS CAUSING AN AREA OF CONVECTION OVER SRN MEXICO. SEE TROPICAL WAVE SECTION ABOVE FOR MORE DETAILS. THE REMAINDER OF THE BASIN IS DOMINATED BY SURFACE RIDGING AROUND A 1017 MB HIGH OFF THE NW COAST OF FLORIDA NEAR 28N85W. THIS RIDGE IS SUPPORTED BY AN UPPER LEVEL RIDGE CENTERED OVER CENTRAL ALABAMA. AN UPPER LEVEL TROUGH COVERS THE FAR WRN GULF CENTERED OVER NRN TEXAS. DRY AIR IS WRAPPING AROUND THE SRN EXTENT OF THE UPPER RIDGE ACROSS THE FLORIDA STRAITS AND INTO THE CENTRAL GULF WHICH IS SUPPORTING FAIR WEATHER ACROSS MUCH OF THE BASIN. HOWEVER...A SHORTWAVE UPPER LEVEL TROUGH PERTURBS INTO THE UPPER RIDGE FROM THE W ATLC AND ACROSS NRN FLORIDA. THIS TROUGH COMBINED WITH THE EFFECTS OF ENHANCED MOISTURE IS CURRENTLY ENHANCING AN AREA OF STRONG SHOWERS AND THUNDERSTORMS ACROSS SW FLORIDA FROM LAKE OKEECHOBEE TO BETWEEN SARASOTA AND FORT MYERS. A FEW ISOLATED SHOWERS ARE ELSEWHERE WITHIN 120 NM OF THE W FLORIDA COAST N OF 25N. EXPECT THE TROPICAL WAVE TO MOVE WWD TOWARDS MEXICO AS WEAK SURFACE RIDGING CONTINUES ACROSS THE REMAINDER OF THE BASIN. CARIBBEAN SEA... A WEAK SURFACE TROUGH EXTENDS ACROSS WRN CUBA...BUT CURRENTLY NOT CAUSING ANY ACTIVE WEATHER DUE TO DRY AIR WRAPPING AROUND THE SRN END OF AN UPPER LEVEL RIDGE OVER THE ERN GULF. AN UPPER LEVEL TROUGH COVERS THE NW CARIBBEAN CENTERED NEAR 18N82W. AN UPPER LEVEL RIDGE COVERS THE CENTRAL CARIBBEAN CENTERED N OF VENEZUELA. THIS PATTERN IS CREATING MOIST SWLY FLOW ALOFT FROM COSTA RICA TO THE WINDWARD PASSAGE. THIS AREA OF DIFFLUENCE IS ALSO ABOVE A TROPICAL WAVE ACROSS WRN JAMAICA. THIS COMBINATION IS SUPPORTING SCATTERED SHOWERS/THUNDERSTORMS FROM 11N-20N BETWEEN 76W-86W. SIMILAR ACTIVITY IS S OF 11N ACROSS COSTA RICA AND PANAMA INFLUENCED BY THE MONSOON TROUGH THAT EXTENDS FROM THE E PACIFIC ACROSS COSTA RICA TO NRN COLOMBIA. MODEL GUIDANCE STILL INDICATES THAT THE MONSOON TROUGH WILL BEGIN TO LIFT N LATER IN THE WEEK ACROSS SRN MEXICO AND THE NRN CENTRAL CARIBBEAN WHICH WILL CONCENTRATE SHOWER ACTIVITY OVER THESE AREAS. THE ERN CARIBBEAN IS UNDER MOSTLY FAIR CONDITIONS IN ELY 20-25 KT TRADEWINDS. A FEW EMBEDDED SHOWERS ARE EMBEDDED IN THE ELY FLOW ACROSS THE NE CARIBBEAN WITH A CLUSTER OF THUNDERSTORMS CURRENTLY OVER THE MONA PASSAGE. A TROPICAL WAVE E OF THE LESSER ANTILLES IS EXPECTED TO IMPACT THE BASIN LATER IN THE WEEK. ATLANTIC OCEAN... WEAK SURFACE RIDGING DOMINATES THE WRN ATLC MAINTAINING MOSTLY FAIR CONDITIONS. THE RIDGE IS SUPPORTED BY AN UPPER LEVEL RIDGE CENTERED OVER CENTRAL ALABAMA WITH ANTICYCLONIC CIRCULATION EXTENDING TO 60W. HOWEVER...A SHORTWAVE UPPER TROUGH EXTENDS INTO THE UPPER RIDGE ALONG 37N58W 31N72W 29N82W. THIS UPPER TROUGH IS SUPPORTING AN AREA OF ISOLATED SHOWERS/POSSIBLE THUNDERSTORMS N OF 29N BETWEEN 60W-78W. AN UPPER LEVEL LOW IS SPINNING IN THE CENTRAL ATLC NEAR 30N55W SUPPORTING A SURFACE TROUGH ALONG 31N55W TO 25N58W. SCATTERED SHOWERS ARE WITHIN 120 NM E OF THE AXIS. THE REMAINDER OF THE BASIN IS DOMINATED BY SURFACE RIDGING AROUND A 1029 MB HIGH NEAR 35N36W PROVIDING FAIR WEATHER. ALOFT...AN UPPER LEVEL RIDGE COVERS THE MAJORITY OF THE ERN ATLC CENTERED SW OF THE AZORES ISLANDS. A NARROW UPPER LEVEL TROUGH EXTENDS FROM THE CANARY ISLANDS TO JUST N OF THE CAPE VERDE ISLANDS CAUSING NO ACTIVITY WEATHER IN THE DISCUSSION AREA. FOR ADDITIONAL INFORMATION PLEASE VISIT HTTP://WWW.HURRICANES.GOV/MARINE $$ WALTON