000 AXNT20 KNHC 071742 TWDAT TROPICAL WEATHER DISCUSSION NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL 205 PM EDT MON AUG 07 2006 TROPICAL WEATHER DISCUSSION FOR NORTH AMERICA...CENTRAL AMERICA...THE GULF OF MEXICO...THE CARIBBEAN SEA...NORTHEASTERN SECTIONS OF SOUTH AMERICA...AND THE 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 1700 UTC. ...SPECIAL FEATURE... A 1009 MB ATLANTIC OCEAN LOW PRESSURE CENTER IS NEAR 12N40W...OR ABOUT 1100 NM EAST OF THE SOUTHERN WINDWARD ISLANDS...MOVING WEST NEAR 15 KT. ALTHOUGH THUNDERSTORM ACTIVITY IS CURRENTLY LIMITED...ENVIRONMENTAL CONDITIONS APPEAR SOMEWHAT FAVORABLE FOR FURTHER DEVELOPMENT AND A TROPICAL DEPRESSION COULD FORM LATER TODAY OR TOMORROW. ...TROPICAL WAVES... AN ATLANTIC OCEAN TROPICAL WAVE IS ALONG 23W SOUTH OF 19N MOVING WEST 10 TO 15 KT. THE EXACT POSITION OF THIS WAVE IS BECOMING DIFFICULT TO LOCATE AS IT BECOMES SUPERIMPOSED UPON THE MONSOON TROUGH...THOUGH BROAD CYCLONIC CURVATURE IS STILL OBSERVED ABOUT THE AXIS. THE SURFACE LOW THAT WAS PREVIOUSLY ANALYZED ALONG THE WAVE IS NO LONGER EVIDENT FROM THIS MORNINGS SATELLITE ANIMATIONS. HOWEVER...A SMALL SWIRL OF LOW CLOUDS WAS NOTED ON VISIBLE IMAGERY ABOUT 230NM W OF THE AXIS NEAR 14N19W. THIS SMALL VORTICITY MAXIMUM SEEMS TO BE WEAKENING SINCE 12Z THOUGH. SHOWER AND TSTM ACTIVITY IS MOSTLY ISOLATED WITHIN 250NM OF EITHER SIDE OF THE AXIS...WITH A SMALL PATCH OF MODERATE CONVECTION NOTED FROM 7N TO 10N BETWEEN 23W AND 27W. THIS MAY BE MORE ASSOCIATED WITH THE ITCZ THOUGH. AN EASTERN CARIBBEAN SEA TROPICAL WAVE IS ALONG 67W/68W SOUTH OF 23N MOVING WEST 15 TO 20 KT. SCATTERED MODERATE/ISOLATED STRONG CONVECTION IS EXTENDING NORTH FROM PUERTO RICO...THE MONA PASSAGE...AND ERN HISPANIOLA FROM 16N TO 24N BETWEEN 66W AND 72W. MUCH OF THE WESTERN PORTION OF THIS WAVE THAT LIES IN THE CARIBBEAN IS SHOWER/TSTM FREE DUE TO EXTENSIVE DRY AIR AND DENSE SAHARAN DUST IN THE VICINITY. ...THE ITCZ... ITCZ AXIS IS CENTERED ALONG 14N17W 12N21W 12N26W 11N36W 11N46W TO THE SOUTH AMERICAN COAST NEAR 9N61W. SCATTERED SHOWER AND TSTMS WITH EMBEDDED ISOLATED MODERATE CONVECTION LIES MAINLY SOUTH OF THE AXIS FROM 3N TO 12N BETWEEN THE AFRICAN COAST AND 35W. ONLY ISOLATED SHOWERS AND TSTMS ARE NOTED W OF 35W THROUGH THE S AMERICAN COAST. A SMALL PATCH OF MODERATE CONVECTION IS MOVING INTO THE SOUTHERN CARIBBEAN SEA OFF THE N COAST OF PANAMA...NORTH OF THE PORTION OF THE AXIS THAT EXTENDS INTO THE E PACIFIC. ...DISCUSSION... THE GULF OF MEXICO... A SURFACE TROUGH...THE REMNANTS OF T.D. CHRIS...IS OVER THE CENTRAL GULF OF MEXICO ALONG 28N89W 22N89W. ISOLATED SHOWERS AND TSTMS ARE SPOTTING THE AREA FROM 22N TO THE GULF COAST BETWEEN 87W AND 93W. THE OTHER AREA OF UNSETTLED WEATHER IN THE GULF IS LOCATED IN THE WESTERN BAY OF CAMPECHE WHERE SCATTERED SHOWERS/TSTMS WITH ISOLATED MODERATE CONVECTION LIES FROM 18N TO 24N BETWEEN 93W AND 98W. AN OUTFLOW BOUNDARY IS SEEN ON VISIBLE IMAGERY MOVING RADIALLY OUTWARD FROM THE N/NE PORTION OF THIS CONVECTION. THIS ACTIVITY SEEMS TO BE ASSOCIATED WITH UPPER DIFFLUENT AIR BETWEEN UPPER ANTICYCLONIC MOTION IN THE VICINITY...ALONG WITH SOME WEAK SURFACE TROUGHING AS ANALYZED IN THE 15Z MAP. WV IMAGERY SHOWS BROAD EASTERLY FLOW BLANKETING MUCH OF THE GULF THIS AFTERNOON...ON THE SOUTH SIDE OF THE UPPER HIGH CENTERED NEAR HUNTSVILLE ALABAMA. SOME WEAK SURFACE TROUGHING MAY PERSIST IN THE FAR SW GULF OVER THE NEXT 24 TO 48HRS WHILE THE SHOWERS/TSTMS ASSOCIATED WITH THE TROUGH/REMNANTS OF CHRIS MOVE W TOWARDS S TEXAS. OTHERWISE...5-15KT E/SE WINDS WILL DOMINATE ON THE W/SW PORTION OF THE ATLANTIC HIGH. THE CARIBBEAN SEA... AN UPPER LEVEL HIGH IS CENTERED OVER THE NORTHERN LEEWARD ISLANDS THIS AFTERNOON. UPPER DIFFLUENT AIR BETWEEN THIS FEATURE AND UPPER TROUGHING TO ITS EAST...NAMELY FROM S OF JAMAICA EXTENDING NE OF THE BAHAMAS...IS INTERACTING WITH THE TROPICAL WAVE IN THE AREA TO GENERATE THE MODERATE CONVECTION THAT IS EXTENDING N THROUGH THE CARIBBEAN WATERS JUST S OF PUERTO RICO AND HISPANIOLA. ISOLATED SHOWERS AND THUNDERSTORMS LIE E OF THE TROPICAL WAVE AXIS ALONG 68W...FROM 11N TO 17N BETWEEN 61W AND 68W. MUCH OF THE CENTRAL CARIBBEAN WATERS W OF THIS AREA IS UNDER THE INFLUENCE OF VERY DRY AIR...FAIR WEATHER...AND DENSE AFRICAN DUST AS ANALYZED ON THE 12Z UW-CIMSS SAHARAN LAYER ANALYSIS. THE EXCEPTION IS THE NW CARIBBEAN ESPECIALLY BETWEEN JAMAICA AND WRN CUBA WHERE SCATTERED MODERATE CONVECTION LIES...ANOTHER UPPER DIFFLUENT AREA BETWEEN THE UPPER LOW NEAR THE BAHAMAS AND THE EASTERLY FLOW ON THE S PORTION OF THE UPPER HIGH OVER THE SE US. AT THE SURFACE...15 TO 25 KT TRADE FLOW DOMINATES ON THE S/SW PORTION OF THE ATLANTIC HIGH. THIS MORNINGS QUIKSCAT PASS DID SHOW SLIGHTLY STRONGER 30 KT WINDS JUST OFF THE COLOMBIAN COAST AS THE HIGH INTERACTS WITH THE COLOMBIAN LOW. THIS IS EXPECTED TO PERSIST OVER THE NEXT COUPLE OF DAYS...THOUGH THE CONVECTION ASSOCIATED WITH THE TROPICAL WAVE WILL MOVE W BRINGING SHOWERS/TSTMS...LOCALLY HEAVY AT TIMES...TO HISPANIOLA...JAMAICA...CUBA...AND THE BAHAMAS. THE ATLANTIC OCEAN... UPPER LEVEL NE/ENE FLOW IS HOVERING OVER FLORIDA AND THE ADJACENT ATLC WATERS THIS AFTERNOON BETWEEN THE UPPER HIGH OVER NRN ALABAMA AND THE UPPER LOW JUST E OF THE BAHAMAS. THE NRN PORTION OF THE TROPICAL WAVE EXTENDING THROUGH THE MONA PASSAGE IS COMBINING WITH UPPER DIFFLUENT AIR TO GENERATE A CLUSTER OF MODERATE CONVECTION IN THE SW ATLC JUST E OF THE TURKS AND CAICOS. SEE TROPICAL WAVE SECTION ABOVE FOR MORE INFO. AN UPPER HIGH IS LOCATED OVER THE NRN LEEWARD ISLANDS. JUST TO THE ENE LIES AN UPPER LOW CENTERED NEAR 22N54W. THIS LOW IS STRUGGLING TO FIND MOISTURE WITH A BROAD AREA OF DRY AIR AND SAHARAN DUST IN THE VICINITY. UPPER CYCLONIC MOTION IS ALSO SEEN FROM 23N TO 30N BETWEEN 36W AND 50W...AND EXTENDING FURTHER N OUT OF THE TPC TAFB AREA OF RESPONSIBILITY. BROAD ANTICYCLONIC FLOW IS SEEN IN THE FAR ERN ATLC WITH AN UPPER HIGH EXTENDING OFF THE W AFRICAN COAST TO NEAR 35W. AT THE SFC ASIDE FROM THE SPECIAL FEATURES AND TROPICAL WAVE...5-15KT E FLOW DOMINATES MUCH OF THE AREA ON THE S/SW SIDE OF A 1029MB HIGH ANALYZED NEAR 43N26W. ANOTHER 1024MB SFC HIGH IS LOCATED NEAR 28N64W. A NON-TROPICAL LOW IS LOCATED ABOUT 700 MILES WEST-SOUTHWEST OF THE AZORES. SHOWER ACTIVITY WITH THIS SYSTEM IS DISORGANIZED AND DEVELOPMENT...IF ANY...IS EXPECTED TO BE SLOW TO OCCUR. $$ WILLIS