000 AXNT20 KNHC 312337 AAA TWDAT TROPICAL WEATHER DISCUSSION NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL 805 PM EDT MON JUL 31 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 1800 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 2315 UTC. ...SPECIAL FEATURE... A 1011 MB LOW HAS DEVELOPED ABOUT 200 MILES EAST OF THE LESSER ANTILLES NEAR 16.5N 58.5W. SURFACE OBSERVATIONS INDICATE THAT THIS WEAK CIRCULATION IS AT THE SURFACE. ASSOCIATED SHOWER AND TSTM ACTIVITY IS LIMITED AND CONFINED TO A SMALL AREA FROM 15N-17.5N BETWEEN 56W-58.5W. ENVIRONMENTAL CONDITIONS ARE ONLY MARGINALLY FAVORABLE FOR ADDITIONAL DEVELOPMENT...HOWEVER...ONLY A SMALL INCREASE IN ORGANIZATION WOULD RESULT IN THE FORMATION OF A TROPICAL DEPRESSION. REGARDLESS IF THAT OCCURS...SHOWERS...TSTMS AND SPORADIC GUSTY WINDS WILL BE SPREADING ACROSS THE EASTERN CARIBBEAN ON TUE AS THIS SYSTEM MOVES TO THE WEST-NORTHWEST AT ABOUT 10-15 KT. ...TROPICAL WAVES... A TROPICAL WAVE IS ADDED TO THE 18 UTC SURFACE ANALYSIS NEAR THE CAPE VERDE ISLANDS ALONG 23W/24W SOUTH OF 17N MOVING W NEAR 15 KT. SATELLITE IMAGERY FROM THIS EVENING CLEARLY SHOWS WELL-DEFINED CYCLONIC CURVATURE AND A CLASSIC INVERTED V-SHAPE. FURTHERMORE...THE DAKAR UPPER AIR TIME SECTION ANALYSIS SHOWS THAT N WINDS VEERED SE INDICATING A WAVE PASSAGE ON SUNDAY. THIS WAVE IS EMBEDDED IN A FAIRLY STABLE ENVIRONMENT LIKELY SUPPRESSING ANY AREAS OF SIGNIFICANT CONVECTION. SCATTERED SHOWERS ARE WITHIN 180 NM OF THE ANALYZED WAVE AXIS AND WITHIN 300 NM EAST OF THE AXIS. MORE CONCENTRATED ACTIVITY IS EMBEDDED WITHIN THE ITCZ AHEAD OF THE WAVE. A TROPICAL WAVE IS ALONG 62W/63W SOUTH OF 13N MOVING W NEAR 15 KT. YESTERDAY THIS FEATURE WAS ANALYZED AS A HIGH AMPLITUDE WAVE ASSOCIATED WITH THE 1011 MB LOW EAST OF THE LESSER ANTILLES WHICH IS DISCUSSED IN THE SPECIAL FEATURE SECTION ABOVE. SINCE THEN...IT HAS BECOME MORE APPARENT ON SATELLITE IMAGERY AND THE AVAILABLE SFC DATA THAT THE LOW PRES SYSTEM HAS BECOME DETACHED FROM THE WAVE. THIS TROPICAL WAVE IS NOW FAIRLY LOW AMPLITUDE BUT SEEMS TO BE ENHANCING CONVECTION OVER NORTHERN PORTIONS OF SOUTH AMERICA SOUTH OF THE ITCZ...WHERE ISOLATED SHOWERS AND TSTMS LIE FROM 2N TO 10N BETWEEN 62W AND 73W. A TROPICAL WAVE IS ALONG 84W/85W SOUTH OF 21N MOVING WEST 15 TO 20 KT THROUGH THE WESTERN CARIBBEAN SEA. THIS WAVE HAS SOME SLIGHT BROAD CYCLONIC TURNING EVIDENT ON SATELLITE IMAGERY AND SURROUNDING BUOYS. THE WAVE INTERACTING WITH A WELL-DEFINED UPPER LEVEL LOW MAY BE ENHANCING ISOLATED MODERATE CONVECTION THAT IS DOTTING THE W CARIBBEAN FROM 12N TO 22N BETWEEN 79W AND 90W. MUCH MORE NUMEROUS MODERATE CONVECTION EXISTS ACROSS JAMAICA...E CUBA...HISPANIOLA AND THE BAHAMAS...BUT THIS UNSETTLED WEATHER IS PRIMARILY DUE TO UPPER DIFFLUENCE AND SFC CONVERGENCE FROM A SFC TROF AND UPPER LOW. THE EXTREME NORTHERN PORTION OF A MOSTLY E PACIFIC TROPICAL WAVE ALONG 97W EXTENDS THROUGH S MEXICO. THIS WAVE IS NOT VERY WELL DEFINED AND IS ONLY PRODUCING A FEW SCATTERED SHOWERS IN THE FAR SW GULF OF MEXICO AND OVER S MEXICO. THIS FEATURE WILL CONTINUE MOVING WEST OF THE AREA. ...ITCZ... ITCZ AXIS IS CENTERED ALONG 12N15W 8N35W 13N54W 11N64W TO PANAMA. BESIDES FOR THE CONVECTION ASSOCIATED WITH THE TROPICAL WAVES...WEAKENING PATCHES OF MODERATE CONVECTION IS WITHIN 180 NM EITHER SIDE OF THE AXIS BETWEEN 26W-46W. ...DISCUSSION... THE GULF OF MEXICO... AN UPPER RIDGE CENTERED OVER THE SOUTHERN U.S. COVERS THE E GULF AND FLORIDA. THIS UPPER HIGH IS ADVECTING A FAIR AMOUNT OF MOISTURE FROM A MODERATE-HIGH UPPER DIFFLUENCE ZONE OFF THE EAST COAST OF FLORIDA INTO THE NRN GULF. A SMALL WEAK UPPER LEVEL LOW OVER THE FL PANHANDLE IS ENHANCING SOME OF THIS DIFFLUENCE ALONG THE GULF COAST. SCATTERED SHOWERS AND TSTMS LIE N OF 27N E OF 91W. ELSEWHERE IN THE UPPER LEVELS...A SMALL UPPER LEVEL LOW IS IN THE NW CORNER OF THE AREA NEAR 28N95W. AN UPPER HIGH IS CENTERED OVER S MEXICO NEAR 18N96W WITH BROAD RIDGING EXTENDING INTO THE CARIBBEAN. MODERATE SUBSIDENCE LIES ABOVE THE CENTRAL GULF. AT THE SFC...WEAK RIDGING IS THE THEME WITH A 1018 MB HIGH CENTERED ALONG THE GEORGIA/FLORIDA BORDER. BROAD 10-15 KT E-SELY FLOW DOMINATES THE REGION. LITTLE CHANGE IN THE SFC PATTERN IS EXPECTED THRU MID-WEEK. FAIRLY DRY WEATHER IS ANTICIPATED ACROSS MUCH OF THE REGION TOMORROW WITH THE BEST CHANCE OF RAIN ON THE EDGES IN THE NRN AND SRN PORTIONS OF THE GULF. THE CARIBBEAN SEA... CLUSTERS OF MODERATE CONVECTION HAS BLOSSOMED THIS LATE AFTERNOON AND EVENING ACROSS JAMAICA...E CUBA...HAITI AND THE SE BAHAMAS ASSOCIATED WITH STRONG UPPER DIFFLUENCE BETWEEN A WELL-DEFINED LARGE UPPER LEVEL LOW CENTERED NEAR 25N72W AND AN BROAD UPPER RIDGE STRETCHING FROM S MEXICO. THE UPPER LOW HAS A SFC REFLECTION AS A TROUGH ALONG 72W EXTENDING FROM HAITI TO 27N. THIS CONVECTION COVERS A LARGE AREA NAMELY FROM 16N TO 22N BETWEEN 69W AND 83W. THE MOST INTENSE OF THIS CONVECTION LIES ON THE EASTERN PART OF JAMAICA AND BETWEEN EASTERN CUBA AND HAITI WHERE CLOUD TOPS HAVE COOLED TO -78C TO -82C. THE OTHER MAIN FEATURE IS A 1011 MB LOW APPROACHING THE EASTERN CARIBBEAN...SEE SPECIAL FEATURE. SHOWERS AND TSTMS WILL BEGIN MOVING INTO THE LESSER ANTILLES LATE TONIGHT OR TOMORROW MORNING AND WILL BECOME MUCH MORE NUMEROUS LATE TUE INTO WED. MODEST 10-15 KT E/SE SFC WINDS DOMINATE MUCH OF THE CARIBBEAN SEA THIS EVENING...ROTATING CLOCKWISE AROUND THE W/SW EXTENSION OF THE ATLANTIC HIGH. GFS SUGGESTS SURFACE WINDS WILL INCREASE A TOUCH ESPECIALLY IN THE CENTRAL CARIBBEAN OVER THE NEXT COUPLE OF DAYS AS THE GRADIENT TIGHTENS BETWEEN A HIGH TO THE N/NE AND LOWER PRESSURE NEAR COLOMBIA...ALONG WITH THE NEXT TROPICAL WAVE AND LOW PRES SYSTEM PROPAGATING WNWWARD THRU THE AREA. THE ATLANTIC OCEAN... A SHARP UPPER TROUGH EXTENDS FROM 32N67W ACROSS THE BAHAMAS AND TURKS AND CAICOS ISLANDS WITH A WELL-DEFINED UPPER LOW NEAR 25N72W. A 1010 MB LOW IS LOCATED A COUPLE HUNDRED MILES E OF CAPE HATTERAS NORTH CAROLINA. STRONG UPPER LEVEL N/NE WINDS ON THE NW PORTION OF THIS UPPER TROUGH ARE SHEARING THE CLOUD TOPS LEAVING THE LOW LEVEL CENTER EXPOSED. UPPER DIFFLUENCE BETWEEN THE UPPER TROUGH AND AN UPPER RIDGE CENTERED N OF THE VIRGIN ISLANDS IS GENERATING SCATTERED SHOWERS AND TSTMS COVERING THE REGION BETWEEN 62W-78W. THE MORE NUMEROUS CONVECTIVE ACTIVITY IS IN THE CARIBBEAN WHERE UPPER DIFFLUENCE IS STRONGER. EAST OF THE RIDGE...AN UPPER TROUGH EXTENDS FROM 32N44W TO NEAR 21N55W. AN ASSOCIATED DISSIPATING COLD FRONT CLIPS THE AREA ALONG 32N50W 29N54W. FARTHER EAST...A LARGE UPPER RIDGE IS CENTERED JUST WEST OF THE AFRICAN COAST NEAR 20N26W. NORTH OF THIS CENTER LIES AN EXTENSIVE AREA OF DRY/STABLE UPPER LEVEL AIR ALONG WITH A DENSE LAYER OF SAHARAN DUST SPREADING OUT TO ABOUT 48W. AT THE SFC...A 1027 MB HIGH IS CENTERED JUST SOUTH OF THE AZORES NEAR 36N27W AND A 1022 MB HIGH IS CENTERED NEAR 25N49W. $$ CANGIALOSI