000 AXNT20 KNHC 072357 TWDAT TROPICAL WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 805 PM EDT THU JUL 07 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 1800 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 2315 UTC. ...SPECIAL FEATURES... A 1011 MB SURFACE LOW IS LOCATED IN THE ERN GULF OF MEXICO NEAR 25N86W CAUSING A LARGE AREA OF CONVECTION ACROSS THE ERN GULF AND FLORIDA. A SURFACE TROUGH EXTENDS FROM THE LOW CENTER TO NEAR 31N78W. THE AREA ALSO LIES UNDERNEATH AN AREA OF DIFFLUENCE ALOFT AROUND THE ERN SIDE OF AN UPPER LEVEL LOW NEAR 28N89W. CURRENTLY NUMEROUS STRONG CONVECTION IS OVER NRN FLORIDA FROM 27N-30N BETWEEN 81W-83W. SCATTERED MODERATE/ISOLATED STRONG CONVECTION IS FROM 23N-30N BETWEEN 78W-86W. UPPER LEVEL CONDITIONS ARE EXPECTED TO BECOME MARGINALLY FAVORABLE FOR FURTHER DEVELOPMENT OVER THE NEXT COUPLE OF DAYS AS THE SYSTEM MOVES N OR NNE. REGARDLESS OF DEVELOPMENT...ENHANCED MOISTURE AND SHOWER ACTIVITY...SOME HEAVY...IS EXPECTED ACROSS MUCH OF THE FLORIDA PENINSULA AND PANHANDLE. ...TROPICAL WAVES... TROPICAL WAVE HAS MOVED OFF THE W COAST OF AFRICA AND IS APPROACHING THE CAPE VERDE ISLANDS ALONG 18N22W TO 8N25W MOVING W 10-15 KT. WITH THE USE OF LONG-TERM SATELLITE IMAGERY THE WAVE CAN BE TRACED BACK ACROSS AFRICA FOR SEVERAL DAYS. THE WAVE PRECEDES A SURGE OF DEEP LAYER MOISTURE THAT EXTENDS TO THE AFRICAN COAST. NO DEEP CONVECTION IS CURRENTLY ASSOCIATED WITH THE WAVE. TROPICAL WAVE IN THE WRN TROPICAL ATLC EXTENDS FROM 12N50W TO 4N53W MOVING W NEAR 20 KT. THE WAVE REMAINS LOW AMPLITUDE BUT IS IN AN AREA OF ENHANCED MOISTURE. SCATTERED MODERATE/STRONG CONVECTION IS MAINLY W OF THE WAVE AXIS FROM 9N-11N BETWEEN 49W-55W...AND FROM 6N-12N BETWEEN 57W-60W. TROPICAL WAVE IS MOVING ACROSS THE NE CARIBBEAN APPROACHING PUERTO RICO FROM 21N64W TO 15N66W MOVING W 15-20 KT. THE WAVE IS EMBEDDED WITHIN A LARGE AREA OF DEEP LAYER MOISTURE COVERING THE ERN CARIBBEAN EVIDENT IN TOTAL PRECIPITABLE WATER IMAGERY. NUMEROUS STRONG CONVECTION IS FROM 14N-17N BETWEEN 64W-67W...AND FROM 15N-17N BETWEEN 61W-63W. SCATTERED MODERATE/STRONG CONVECTION COVERS THE REMAINDER OF THE AREA FROM 14N-20N BETWEEN 60W-69W...AND FROM 14N-17N BETWEEN 70W-74W. TROPICAL WAVE IS OVER THE BAY OF CAMPECHE ALONG 24N92W TO 17N93W MOVING W NEAR 10 KT. THIS WAVE HAS WEAKENED DUE TO INTERACTION WITH AN UPPER LEVEL TROUGH OVER THE GULF OF MEXICO AND THE SURFACE TROUGH MENTIONED IN THE SPECIAL FEATURE SECTION. DRY AIR ALOFT IS BEING DRAWN AROUND THE UPPER TROUGH WHICH IS INHIBITING DEEP CONVECTION NEAR THE WAVE AXIS. ...ITCZ/MONSOON TROUGH... THE MONSOON TROUGH EXTENDS ACROSS AFRICA FROM THE PRIME MERIDIAN AT 20N ALONG 21N6W 13N15W 10N22W. ITCZ CONTINUES ON THE OTHER SIDE OF A TROPICAL WAVE ALONG 10N26W TO 6N49W. A CLUSTER OF STRONG CONVECTION IS MOVING OFF THE W AFRICAN COAST FROM 6N-9N BETWEEN 11W-18W...WITH SCATTERED MODERATE/ISOLATED STRONG CONVECTION TO THE N FROM 9N-12N BETWEEN 16W-20W. ISOLATED MODERATE/STRONG CONVECTION IS FROM 7N-9N BETWEEN 31W-39W. ...DISCUSSION... GULF OF MEXICO... AN UPPER LEVEL LOW CONTINUES TO SPIN OVER THE GULF OF MEXICO THIS EVENING NEAR 28N89W WITH CYCLONIC FLOW COVERING THE BASIN. DRY AIR IS WRAPPING AROUND THE WRN AND SRN SIDE OF THE UPPER TROUGH DIMINISHING SHOWER ACTIVITY NEAR A TROPICAL WAVE IN THE BAY OF CAMPECHE...AND IS MAINTAINING FAIR SURFACE CONDITIONS W OF 89W. THE ERN GULF IS A DIFFERENT STORY WITH ENHANCED MOISTURE VALUES COVERING THE AREA NEAR A 1011 MB SURFACE LOW CENTERED NEAR 25N86W...AS OF 2100 UTC. A SURFACE TROUGH EXTENDS NE FROM THE LOW CENTER ACROSS N/CENTRAL FLORIDA. SHOWER/THUNDERSTORM ACTIVITY RANGES FROM THE YUCATAN PENINSULA...WRN CUBA...AND THE MAJORITY OF FLORIDA WITH THE STRONGEST ACTIVITY CURRENTLY ACROSS THE NW FLORIDA PENINSULA. SEE THE SPECIAL FEATURES SECTION FOR MORE DETAILS ABOUT THIS SURFACE LOW. UPPER LEVEL DIFFLUENCE AROUND THE ERN SIDE OF THE UPPER LOW IS ALSO ENHANCING THIS ACTIVITY. EXPECT MOIST CONDITIONS AND WIDESPREAD SHOWER ACTIVITY TO REMAIN ACROSS THE ERN GULF AS THE AREA OF LOW PRESSURE DRIFTS N OR NNE. CARIBBEAN SEA... SCATTERED SHOWERS/THUNDERSTORMS ARE ACROSS THE FAR NW CARIBBEAN INCLUDING THE YUCATAN PENINSULA...YUCATAN CHANNEL...AND MUCH OF CUBA DUE TO DEEP LAYER MOISTURE THAT IS EXTENDING FROM THE AREA OF LOW PRESSURE IN THE ERN GULF OF MEXICO. FAIRLY DRY CONDITIONS COVER THE REMAINDER OF THE WRN CARIBBEAN DUE TO DRY AIR ALOFT THAT IS WRAPPING AROUND THE ERN SIDE OF AN UPPER LEVEL RIDGE EXTENDING FROM THE YUCATAN PENINSULA AND INTO THE FAR WRN ATLC. HOWEVER...A FEW ISOLATED SHOWERS ARE STILL EMBEDDED IN THE ELY TRADEWIND FLOW...AS WELL AS ACROSS THE SW CARIBBEAN INFLUENCED BY THE MONSOON TROUGH THAT EXTENDS FROM THE E PACIFIC ACROSS NRN COSTA RICA TO NRN COLOMBIA. THE CENTRAL AND ERN CARIBBEAN ARE RECEIVING A GOOD AMOUNT OF SHOWERS/THUNDERSTORMS DUE TO A TROPICAL WAVE CURRENTLY JUST E OF PUERTO RICO. SEE TROPICAL WAVE SECTION FOR MORE DETAILS. THE WAVE IS BEING ENHANCED BY AN UPPER LEVEL TROUGH EXTENDING FROM THE CENTRAL ATLC TO THE MONA PASSAGE. CURRENTLY SHOWER/THUNDERSTORM ACTIVITY IS FROM 14N-20N BETWEEN 60W-69W...AND FROM 14N-17N BETWEEN 70W-74W WITH THE STRONGEST ACTIVITY NEAR THE WAVE AXIS S OF PUERTO RICO AND VIRGIN ISLANDS. ALL OF THE NE AND N CENTRAL CARIBBEAN ISLANDS SHOULD EXPECT THE POSSIBILITY OF HEAVY SHOWERS/THUNDERSTORMS AS THE WAVE MOVES WWD. ELSEWHERE ACROSS THE BASIN...FRESH TO STRONG ELY TRADEWINDS PERSIST. ATLANTIC OCEAN... SCATTERED SHOWERS/THUNDERSTORMS ARE ACROSS THE FAR SW ATLC W OF 78W DUE TO AN AREA OF LOW PRESSURE ACROSS THE GULF OF MEXICO. A SURFACE TROUGH EXTENDS ACROSS CENTRAL FLORIDA FROM NEAR 29N81W TO 32N75W AND OUT OF THE DISCUSSION AREA. ALOFT...AN UPPER LEVEL RIDGE EXTENDS FROM THE NW CARIBBEAN AND INTO THE WRN ATLC ALONG 78W. THIS IS DRAWING MOISTURE ALOFT ACROSS FLORIDA AND FURTHER ENHANCING SOME OF THE SHOWER ACTIVITY. A TROPICAL WAVE JUST E OF PUERTO RICO IS ALSO CAUSING SOME SHOWERS/THUNDERSTORMS S OF 20N BETWEEN 56W-67W. SOME OF THIS ACTIVITY IS BEING ENHANCED BY AN UPPER LEVEL TROUGH EXTENDING FROM NEAR 32N49W TO THE MONA PASSAGE. THE REMAINDER OF THE BASIN IS DOMINATED BY A BROAD SURFACE RIDGE ANCHORED AROUND A PAIR OF 1028 MB HIGHS NEAR 34N45W AND 38N29W PROVIDING FAIR WEATHER ACROSS THE AREA. ALOFT...AN UPPER LEVEL RIDGE EXTENDS FROM E OF THE LESSER ANTILLES NEAR 14N56W TO THE AZORES ISLANDS. A SHORTWAVE UPPER TROUGH IS OVER THE CANARY ISLANDS. FOR ADDITIONAL INFORMATION PLEASE VISIT HTTP://WWW.HURRICANES.GOV/MARINE $$ WALTON 000 AXNT20 KNHC 072357 TWDAT TROPICAL WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 805 PM EDT THU JUL 07 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 1800 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 2315 UTC. ...SPECIAL FEATURES... A 1011 MB SURFACE LOW IS LOCATED IN THE ERN GULF OF MEXICO NEAR 25N86W CAUSING A LARGE AREA OF CONVECTION ACROSS THE ERN GULF AND FLORIDA. A SURFACE TROUGH EXTENDS FROM THE LOW CENTER TO NEAR 31N78W. THE AREA ALSO LIES UNDERNEATH AN AREA OF DIFFLUENCE ALOFT AROUND THE ERN SIDE OF AN UPPER LEVEL LOW NEAR 28N89W. CURRENTLY NUMEROUS STRONG CONVECTION IS OVER NRN FLORIDA FROM 27N-30N BETWEEN 81W-83W. SCATTERED MODERATE/ISOLATED STRONG CONVECTION IS FROM 23N-30N BETWEEN 78W-86W. UPPER LEVEL CONDITIONS ARE EXPECTED TO BECOME MARGINALLY FAVORABLE FOR FURTHER DEVELOPMENT OVER THE NEXT COUPLE OF DAYS AS THE SYSTEM MOVES N OR NNE. REGARDLESS OF DEVELOPMENT...ENHANCED MOISTURE AND SHOWER ACTIVITY...SOME HEAVY...IS EXPECTED ACROSS MUCH OF THE FLORIDA PENINSULA AND PANHANDLE. ...TROPICAL WAVES... TROPICAL WAVE HAS MOVED OFF THE W COAST OF AFRICA AND IS APPROACHING THE CAPE VERDE ISLANDS ALONG 18N22W TO 8N25W MOVING W 10-15 KT. WITH THE USE OF LONG-TERM SATELLITE IMAGERY THE WAVE CAN BE TRACED BACK ACROSS AFRICA FOR SEVERAL DAYS. THE WAVE PRECEDES A SURGE OF DEEP LAYER MOISTURE THAT EXTENDS TO THE AFRICAN COAST. NO DEEP CONVECTION IS CURRENTLY ASSOCIATED WITH THE WAVE. TROPICAL WAVE IN THE WRN TROPICAL ATLC EXTENDS FROM 12N50W TO 4N53W MOVING W NEAR 20 KT. THE WAVE REMAINS LOW AMPLITUDE BUT IS IN AN AREA OF ENHANCED MOISTURE. SCATTERED MODERATE/STRONG CONVECTION IS MAINLY W OF THE WAVE AXIS FROM 9N-11N BETWEEN 49W-55W...AND FROM 6N-12N BETWEEN 57W-60W. TROPICAL WAVE IS MOVING ACROSS THE NE CARIBBEAN APPROACHING PUERTO RICO FROM 21N64W TO 15N66W MOVING W 15-20 KT. THE WAVE IS EMBEDDED WITHIN A LARGE AREA OF DEEP LAYER MOISTURE COVERING THE ERN CARIBBEAN EVIDENT IN TOTAL PRECIPITABLE WATER IMAGERY. NUMEROUS STRONG CONVECTION IS FROM 14N-17N BETWEEN 64W-67W...AND FROM 15N-17N BETWEEN 61W-63W. SCATTERED MODERATE/STRONG CONVECTION COVERS THE REMAINDER OF THE AREA FROM 14N-20N BETWEEN 60W-69W...AND FROM 14N-17N BETWEEN 70W-74W. TROPICAL WAVE IS OVER THE BAY OF CAMPECHE ALONG 24N92W TO 17N93W MOVING W NEAR 10 KT. THIS WAVE HAS WEAKENED DUE TO INTERACTION WITH AN UPPER LEVEL TROUGH OVER THE GULF OF MEXICO AND THE SURFACE TROUGH MENTIONED IN THE SPECIAL FEATURE SECTION. DRY AIR ALOFT IS BEING DRAWN AROUND THE UPPER TROUGH WHICH IS INHIBITING DEEP CONVECTION NEAR THE WAVE AXIS. ...ITCZ/MONSOON TROUGH... THE MONSOON TROUGH EXTENDS ACROSS AFRICA FROM THE PRIME MERIDIAN AT 20N ALONG 21N6W 13N15W 10N22W. ITCZ CONTINUES ON THE OTHER SIDE OF A TROPICAL WAVE ALONG 10N26W TO 6N49W. A CLUSTER OF STRONG CONVECTION IS MOVING OFF THE W AFRICAN COAST FROM 6N-9N BETWEEN 11W-18W...WITH SCATTERED MODERATE/ISOLATED STRONG CONVECTION TO THE N FROM 9N-12N BETWEEN 16W-20W. ISOLATED MODERATE/STRONG CONVECTION IS FROM 7N-9N BETWEEN 31W-39W. ...DISCUSSION... GULF OF MEXICO... AN UPPER LEVEL LOW CONTINUES TO SPIN OVER THE GULF OF MEXICO THIS EVENING NEAR 28N89W WITH CYCLONIC FLOW COVERING THE BASIN. DRY AIR IS WRAPPING AROUND THE WRN AND SRN SIDE OF THE UPPER TROUGH DIMINISHING SHOWER ACTIVITY NEAR A TROPICAL WAVE IN THE BAY OF CAMPECHE...AND IS MAINTAINING FAIR SURFACE CONDITIONS W OF 89W. THE ERN GULF IS A DIFFERENT STORY WITH ENHANCED MOISTURE VALUES COVERING THE AREA NEAR A 1011 MB SURFACE LOW CENTERED NEAR 25N86W...AS OF 2100 UTC. A SURFACE TROUGH EXTENDS NE FROM THE LOW CENTER ACROSS N/CENTRAL FLORIDA. SHOWER/THUNDERSTORM ACTIVITY RANGES FROM THE YUCATAN PENINSULA...WRN CUBA...AND THE MAJORITY OF FLORIDA WITH THE STRONGEST ACTIVITY CURRENTLY ACROSS THE NW FLORIDA PENINSULA. SEE THE SPECIAL FEATURES SECTION FOR MORE DETAILS ABOUT THIS SURFACE LOW. UPPER LEVEL DIFFLUENCE AROUND THE ERN SIDE OF THE UPPER LOW IS ALSO ENHANCING THIS ACTIVITY. EXPECT MOIST CONDITIONS AND WIDESPREAD SHOWER ACTIVITY TO REMAIN ACROSS THE ERN GULF AS THE AREA OF LOW PRESSURE DRIFTS N OR NNE. CARIBBEAN SEA... SCATTERED SHOWERS/THUNDERSTORMS ARE ACROSS THE FAR NW CARIBBEAN INCLUDING THE YUCATAN PENINSULA...YUCATAN CHANNEL...AND MUCH OF CUBA DUE TO DEEP LAYER MOISTURE THAT IS EXTENDING FROM THE AREA OF LOW PRESSURE IN THE ERN GULF OF MEXICO. FAIRLY DRY CONDITIONS COVER THE REMAINDER OF THE WRN CARIBBEAN DUE TO DRY AIR ALOFT THAT IS WRAPPING AROUND THE ERN SIDE OF AN UPPER LEVEL RIDGE EXTENDING FROM THE YUCATAN PENINSULA AND INTO THE FAR WRN ATLC. HOWEVER...A FEW ISOLATED SHOWERS ARE STILL EMBEDDED IN THE ELY TRADEWIND FLOW...AS WELL AS ACROSS THE SW CARIBBEAN INFLUENCED BY THE MONSOON TROUGH THAT EXTENDS FROM THE E PACIFIC ACROSS NRN COSTA RICA TO NRN COLOMBIA. THE CENTRAL AND ERN CARIBBEAN ARE RECEIVING A GOOD AMOUNT OF SHOWERS/THUNDERSTORMS DUE TO A TROPICAL WAVE CURRENTLY JUST E OF PUERTO RICO. SEE TROPICAL WAVE SECTION FOR MORE DETAILS. THE WAVE IS BEING ENHANCED BY AN UPPER LEVEL TROUGH EXTENDING FROM THE CENTRAL ATLC TO THE MONA PASSAGE. CURRENTLY SHOWER/THUNDERSTORM ACTIVITY IS FROM 14N-20N BETWEEN 60W-69W...AND FROM 14N-17N BETWEEN 70W-74W WITH THE STRONGEST ACTIVITY NEAR THE WAVE AXIS S OF PUERTO RICO AND VIRGIN ISLANDS. ALL OF THE NE AND N CENTRAL CARIBBEAN ISLANDS SHOULD EXPECT THE POSSIBILITY OF HEAVY SHOWERS/THUNDERSTORMS AS THE WAVE MOVES WWD. ELSEWHERE ACROSS THE BASIN...FRESH TO STRONG ELY TRADEWINDS PERSIST. ATLANTIC OCEAN... SCATTERED SHOWERS/THUNDERSTORMS ARE ACROSS THE FAR SW ATLC W OF 78W DUE TO AN AREA OF LOW PRESSURE ACROSS THE GULF OF MEXICO. A SURFACE TROUGH EXTENDS ACROSS CENTRAL FLORIDA FROM NEAR 29N81W TO 32N75W AND OUT OF THE DISCUSSION AREA. ALOFT...AN UPPER LEVEL RIDGE EXTENDS FROM THE NW CARIBBEAN AND INTO THE WRN ATLC ALONG 78W. THIS IS DRAWING MOISTURE ALOFT ACROSS FLORIDA AND FURTHER ENHANCING SOME OF THE SHOWER ACTIVITY. A TROPICAL WAVE JUST E OF PUERTO RICO IS ALSO CAUSING SOME SHOWERS/THUNDERSTORMS S OF 20N BETWEEN 56W-67W. SOME OF THIS ACTIVITY IS BEING ENHANCED BY AN UPPER LEVEL TROUGH EXTENDING FROM NEAR 32N49W TO THE MONA PASSAGE. THE REMAINDER OF THE BASIN IS DOMINATED BY A BROAD SURFACE RIDGE ANCHORED AROUND A PAIR OF 1028 MB HIGHS NEAR 34N45W AND 38N29W PROVIDING FAIR WEATHER ACROSS THE AREA. ALOFT...AN UPPER LEVEL RIDGE EXTENDS FROM E OF THE LESSER ANTILLES NEAR 14N56W TO THE AZORES ISLANDS. A SHORTWAVE UPPER TROUGH IS OVER THE CANARY ISLANDS. FOR ADDITIONAL INFORMATION PLEASE VISIT HTTP://WWW.HURRICANES.GOV/MARINE $$ WALTON