000 AXNT20 KNHC 071804 TWDAT TROPICAL WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 205 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 1200 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 1530 UTC. ...TROPICAL WAVES... AN ATLANTIC OCEAN TROPICAL WAVE IS ALONG 12N45W TO 02N48W AND IS MOVING W AT 10-15 KT. SCATTERED MODERATE CONVECTION IS PRIMARILY NOTED TO THE W OF THE TROPICAL WAVE TO 56W AND N OF THE ITCZ. AN ATLANTIC OCEAN TROPICAL WAVE IS ALONG 20N58W TO 13N64W AND IS MOVING W-NW AT 10-15 KT. SCATTERED MODERATE WITH ISOLATED STRONG CONVECTION COVERS THE CARIBBEAN SEA AND THE ATLANTIC OCEAN FROM 15N TO 19N BETWEEN THIS WAVE AND A SURFACE TROUGH THAT LIES ALONG 70W S OF 16N AS WELL AS E OF THE WAVE TO 56W FROM 16N TO 20N. A TROPICAL WAVE EXTENDS FROM 24N91W INTO SOUTHEASTERN MEXICO NEAR 17N92W AND IS MOVING W AT 5-10 KT. DEEP CONVECTION HAS DIMINISHED NEAR THIS WAVE. ...THE ITCZ/THE MONSOON TROUGH... A MONSOON TROUGH PASSES THROUGH THE PRIME MERIDIAN ALONG 22N...CURVING TO 12N16W 8N30W. THE ITCZ CONTINUES FROM 08N30W TO 08N44W...REACHING COASTAL BORDER OF BRAZIL AND FRENCH GUIANA NEAR 04N54W. A MONSOON TROUGH ALSO LIES ALONG 11N BETWEEN 72W AND NE COSTA RICA AND THEN EXTENDS NORTHWARD INTO EL SALVADOR. SCATTERED MODERATE CONVECTION LIES WITHIN 90 NM N OF THE MONSOON TROUGH BETWEEN 75W AND NORTHERN COSTA RICA. ...DISCUSSION... THE GULF OF MEXICO... A STRONG UPPER LEVEL LOW LIES NEAR 28N89W. CYCLONIC FLOW ALOFT COVERS THE ENTIRE GULF OF MEXICO. WATER VAPOR IMAGERY INDICATES DRY AIR ALOFT LIES OVER MUCH OF THE GULF W OF 86W WITH SOME HIGH LEVEL MOISTURE BEGINNING TO ADVECT EASTWARD FROM THE NEWLY FORMED TROPICAL DEPRESSION THREE-E IN THE EASTERN PACIFIC INTO THE FAR SW GULF OF MEXICO. A TROPICAL WAVE EXTENDS FROM 24N91W INTO SOUTHEASTERN MEXICO NEAR 17N92W. DEEP CONVECTION HAS DIMINISHED NEAR THIS WAVE UNDER THE DRY AIR ALOFT AND STRONG WESTERLY SHEAR. A SURFACE LOW LIES IN THE SE GULF NEAR 25N84W AND EXTENDS A TROUGH NORTHEASTWARD INTO FLORIDA NEAR CAPE CORAL TO DAYTONA BEACH. SCATTERED MODERATE WITH ISOLATED STRONG CONVECTION ASSOCIATED WITH THIS SYSTEM LIES OVER MUCH OF THE AREA FROM 24N TO 29N E OF 86W AS WELL AS SW OF THE SYSTEM INTO THE YUCATAN CHANNEL. THIS LOW IS FORECAST TO SLOWLY MOVE NW TOWARD THE NORTH CENTRAL GULF OVER THE NEXT TWO DAYS. ALOFT...THE UPPER LOW WILL BE FORCED WESTWARD AS THE UPPER RIDGE THAT CURRENTLY LIES JUST S OF THE GULF LIFTS NORTHEASTWARD AND CUTS OFF AN ANTICYCLONE OVER FLORIDA. THE CARIBBEAN SEA... THE SOUTHERN END OF AN UPPER LEVEL TROUGH PASSES THROUGH THE ATLANTIC OCEAN NEAR 32N50W AND REACHES WESTERN PUERTO RICO BEFORE TURNING SOUTHWARD TO NEAR 12N70W. A TROPICAL WAVE LIES TO THE E OF THE TROUGH FROM 20N58W TO 13N64W. THE CONVECTION NOTED WITH THIS WAVE IS DESCRIBED ABOVE. IT PRIMARILY LIES BETWEEN THE TROPICAL WAVE AND A SURFACE TROUGH ALONG 70W S OF 16N WITH MUCH OF THE NE CARIBBEAN CURRENTLY RECEIVING MODERATE TO HEAVY RAIN. THE TROPICAL WAVE WILL CONTINUE WESTWARD THROUGH THE GREATER ANTILLES OVER THE NEXT FEW DAYS AND BRING CONTINUED RAINFALL WITH IT. FRESH TO STRONG EASTERLY WINDS OVER MUCH OF THE CENTRAL CARIBBEAN ARE BEING FORCED BY A STRONG PRES GRADIENT BETWEEN THE SUBTROPICAL HIGH AND LOWER PRES OVER THE SW CARIBBEAN WHERE A MONSOON TROUGH LIES OVER THE REGION ALONG 11N. SHOWERS AND THUNDERSTORMS ARE CONTAINED TO WITHIN 90 NM N OF THE MONSOON TROUGH AXIS. DRIER AIR ALOFT LIMITS DEEP CONVECTION OVER MUCH OF THE REMAINDER OF THE CARIBBEAN S OF 17N AND W OF 73W. AN UPPER RIDGE LIES OVER THE NW CARIBBEAN FROM THE EASTERN YUCATAN PENINSULA TO CENTRAL CUBA. NORTHERLY WINDS ALOFT ARE TRANSPORTING UPPER MOISTURE ASSOCIATED WITH THE LOW PRES SYSTEM IN THE SE GULF OF MEXICO SOUTHWARD INTO THE NW CARIBBEAN TO 17N. OVERCAST SKIES ARE FOUND OVER MUCH OF THIS AREA WITH SOME SHOWERS AND THUNDERSTORMS NOTED IN THE YUCATAN CHANNEL AND WESTERN CUBA. THE UPPER RIDGE IS FORECAST TO LIFT NORTHWARD AND CARRY THE BEST CHANCE OF PRECIPITATION OUT OF THE REGION LATE TONIGHT. THE ATLANTIC OCEAN... THE UPPER LEVEL RIDGE THAT PASSES THROUGH THE NW CARIBBEAN SEA EMERGES INTO THE STRAITS OF FLORIDA AND EXTENDS NORTHEASTWARD TO 32N74W. THE DIFFLUENCE ALOFT INDUCED BY THIS RIDGE AXIS IS ENHANCING CONVECTION PRIMARILY W OF 77W...INCLUDING THE WESTERN BAHAMAS AND OVER THE SOUTHERN FLORIDA PENINSULA. THIS RIDGE IS EXPECTED TO CUT OFF AN ANTICYCLONE THAT WILL PASS N THROUGH THE FLORIDA PENINSULA OVER THE NEXT FEW DAYS. SHOWERS AND THUNDERSTORMS WILL PERSIST OVER THE AREA AND EXPAND INTO NORTHEAST FLORIDA AND THE OFFSHORE WATERS. AN UPPER LEVEL TROUGH PASSES THROUGH 32N50W AND REACHES WESTERN PUERTO RICO WHILE A SECOND RIDGE AXIS EXTENDS FROM AN ANTICYCLONE NEAR 28N35W TO 13N50W. 40-50 KT WEST-SOUTHWESTERLY WINDS ALOFT LIE BETWEEN THE TROUGH AND RIDGE AXES N OF 20N. THE REAR RIGHT QUADRANT OF THIS JET LIES NEAR THE NE CARIBBEAN AND THE ASSOCIATED UPPER LEVEL DIFFLUENCE IS ENHANCING THE CONVECTION NOTED IN THE SECTION ABOVE NEAR THE TROPICAL WAVE FROM 20N58W TO 13N64W. THE UPPER TROUGH IS EXPECTED TO CUT OFF A LOW NEAR 30N50W TOMORROW WHILE THE ANTICYCLONE WILL WEAKEN AND A NEW ONE WILL FORM OVER THE LESSER ANTILLES. THE INCREASED DIFFLUENCE ALOFT ASSOCIATED WITH THE NEW ANTICYCLONE WILL HELP ENHANCE CONVECTION WITH THE TROPICAL WAVE CURRENTLY FROM 12N45W TO 02N48W AS IT MOVES WESTWARD TOWARD THE ISLANDS. FOR ADDITIONAL INFORMATION PLEASE VISIT HTTP://WWW.HURRICANES.GOV/MARINE $$ SCHAUER 000 AXNT20 KNHC 071804 TWDAT TROPICAL WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 205 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 1200 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 1530 UTC. ...TROPICAL WAVES... AN ATLANTIC OCEAN TROPICAL WAVE IS ALONG 12N45W TO 02N48W AND IS MOVING W AT 10-15 KT. SCATTERED MODERATE CONVECTION IS PRIMARILY NOTED TO THE W OF THE TROPICAL WAVE TO 56W AND N OF THE ITCZ. AN ATLANTIC OCEAN TROPICAL WAVE IS ALONG 20N58W TO 13N64W AND IS MOVING W-NW AT 10-15 KT. SCATTERED MODERATE WITH ISOLATED STRONG CONVECTION COVERS THE CARIBBEAN SEA AND THE ATLANTIC OCEAN FROM 15N TO 19N BETWEEN THIS WAVE AND A SURFACE TROUGH THAT LIES ALONG 70W S OF 16N AS WELL AS E OF THE WAVE TO 56W FROM 16N TO 20N. A TROPICAL WAVE EXTENDS FROM 24N91W INTO SOUTHEASTERN MEXICO NEAR 17N92W AND IS MOVING W AT 5-10 KT. DEEP CONVECTION HAS DIMINISHED NEAR THIS WAVE. ...THE ITCZ/THE MONSOON TROUGH... A MONSOON TROUGH PASSES THROUGH THE PRIME MERIDIAN ALONG 22N...CURVING TO 12N16W 8N30W. THE ITCZ CONTINUES FROM 08N30W TO 08N44W...REACHING COASTAL BORDER OF BRAZIL AND FRENCH GUIANA NEAR 04N54W. A MONSOON TROUGH ALSO LIES ALONG 11N BETWEEN 72W AND NE COSTA RICA AND THEN EXTENDS NORTHWARD INTO EL SALVADOR. SCATTERED MODERATE CONVECTION LIES WITHIN 90 NM N OF THE MONSOON TROUGH BETWEEN 75W AND NORTHERN COSTA RICA. ...DISCUSSION... THE GULF OF MEXICO... A STRONG UPPER LEVEL LOW LIES NEAR 28N89W. CYCLONIC FLOW ALOFT COVERS THE ENTIRE GULF OF MEXICO. WATER VAPOR IMAGERY INDICATES DRY AIR ALOFT LIES OVER MUCH OF THE GULF W OF 86W WITH SOME HIGH LEVEL MOISTURE BEGINNING TO ADVECT EASTWARD FROM THE NEWLY FORMED TROPICAL DEPRESSION THREE-E IN THE EASTERN PACIFIC INTO THE FAR SW GULF OF MEXICO. A TROPICAL WAVE EXTENDS FROM 24N91W INTO SOUTHEASTERN MEXICO NEAR 17N92W. DEEP CONVECTION HAS DIMINISHED NEAR THIS WAVE UNDER THE DRY AIR ALOFT AND STRONG WESTERLY SHEAR. A SURFACE LOW LIES IN THE SE GULF NEAR 25N84W AND EXTENDS A TROUGH NORTHEASTWARD INTO FLORIDA NEAR CAPE CORAL TO DAYTONA BEACH. SCATTERED MODERATE WITH ISOLATED STRONG CONVECTION ASSOCIATED WITH THIS SYSTEM LIES OVER MUCH OF THE AREA FROM 24N TO 29N E OF 86W AS WELL AS SW OF THE SYSTEM INTO THE YUCATAN CHANNEL. THIS LOW IS FORECAST TO SLOWLY MOVE NW TOWARD THE NORTH CENTRAL GULF OVER THE NEXT TWO DAYS. ALOFT...THE UPPER LOW WILL BE FORCED WESTWARD AS THE UPPER RIDGE THAT CURRENTLY LIES JUST S OF THE GULF LIFTS NORTHEASTWARD AND CUTS OFF AN ANTICYCLONE OVER FLORIDA. THE CARIBBEAN SEA... THE SOUTHERN END OF AN UPPER LEVEL TROUGH PASSES THROUGH THE ATLANTIC OCEAN NEAR 32N50W AND REACHES WESTERN PUERTO RICO BEFORE TURNING SOUTHWARD TO NEAR 12N70W. A TROPICAL WAVE LIES TO THE E OF THE TROUGH FROM 20N58W TO 13N64W. THE CONVECTION NOTED WITH THIS WAVE IS DESCRIBED ABOVE. IT PRIMARILY LIES BETWEEN THE TROPICAL WAVE AND A SURFACE TROUGH ALONG 70W S OF 16N WITH MUCH OF THE NE CARIBBEAN CURRENTLY RECEIVING MODERATE TO HEAVY RAIN. THE TROPICAL WAVE WILL CONTINUE WESTWARD THROUGH THE GREATER ANTILLES OVER THE NEXT FEW DAYS AND BRING CONTINUED RAINFALL WITH IT. FRESH TO STRONG EASTERLY WINDS OVER MUCH OF THE CENTRAL CARIBBEAN ARE BEING FORCED BY A STRONG PRES GRADIENT BETWEEN THE SUBTROPICAL HIGH AND LOWER PRES OVER THE SW CARIBBEAN WHERE A MONSOON TROUGH LIES OVER THE REGION ALONG 11N. SHOWERS AND THUNDERSTORMS ARE CONTAINED TO WITHIN 90 NM N OF THE MONSOON TROUGH AXIS. DRIER AIR ALOFT LIMITS DEEP CONVECTION OVER MUCH OF THE REMAINDER OF THE CARIBBEAN S OF 17N AND W OF 73W. AN UPPER RIDGE LIES OVER THE NW CARIBBEAN FROM THE EASTERN YUCATAN PENINSULA TO CENTRAL CUBA. NORTHERLY WINDS ALOFT ARE TRANSPORTING UPPER MOISTURE ASSOCIATED WITH THE LOW PRES SYSTEM IN THE SE GULF OF MEXICO SOUTHWARD INTO THE NW CARIBBEAN TO 17N. OVERCAST SKIES ARE FOUND OVER MUCH OF THIS AREA WITH SOME SHOWERS AND THUNDERSTORMS NOTED IN THE YUCATAN CHANNEL AND WESTERN CUBA. THE UPPER RIDGE IS FORECAST TO LIFT NORTHWARD AND CARRY THE BEST CHANCE OF PRECIPITATION OUT OF THE REGION LATE TONIGHT. THE ATLANTIC OCEAN... THE UPPER LEVEL RIDGE THAT PASSES THROUGH THE NW CARIBBEAN SEA EMERGES INTO THE STRAITS OF FLORIDA AND EXTENDS NORTHEASTWARD TO 32N74W. THE DIFFLUENCE ALOFT INDUCED BY THIS RIDGE AXIS IS ENHANCING CONVECTION PRIMARILY W OF 77W...INCLUDING THE WESTERN BAHAMAS AND OVER THE SOUTHERN FLORIDA PENINSULA. THIS RIDGE IS EXPECTED TO CUT OFF AN ANTICYCLONE THAT WILL PASS N THROUGH THE FLORIDA PENINSULA OVER THE NEXT FEW DAYS. SHOWERS AND THUNDERSTORMS WILL PERSIST OVER THE AREA AND EXPAND INTO NORTHEAST FLORIDA AND THE OFFSHORE WATERS. AN UPPER LEVEL TROUGH PASSES THROUGH 32N50W AND REACHES WESTERN PUERTO RICO WHILE A SECOND RIDGE AXIS EXTENDS FROM AN ANTICYCLONE NEAR 28N35W TO 13N50W. 40-50 KT WEST-SOUTHWESTERLY WINDS ALOFT LIE BETWEEN THE TROUGH AND RIDGE AXES N OF 20N. THE REAR RIGHT QUADRANT OF THIS JET LIES NEAR THE NE CARIBBEAN AND THE ASSOCIATED UPPER LEVEL DIFFLUENCE IS ENHANCING THE CONVECTION NOTED IN THE SECTION ABOVE NEAR THE TROPICAL WAVE FROM 20N58W TO 13N64W. THE UPPER TROUGH IS EXPECTED TO CUT OFF A LOW NEAR 30N50W TOMORROW WHILE THE ANTICYCLONE WILL WEAKEN AND A NEW ONE WILL FORM OVER THE LESSER ANTILLES. THE INCREASED DIFFLUENCE ALOFT ASSOCIATED WITH THE NEW ANTICYCLONE WILL HELP ENHANCE CONVECTION WITH THE TROPICAL WAVE CURRENTLY FROM 12N45W TO 02N48W AS IT MOVES WESTWARD TOWARD THE ISLANDS. FOR ADDITIONAL INFORMATION PLEASE VISIT HTTP://WWW.HURRICANES.GOV/MARINE $$ SCHAUER