000 AXNT20 KNHC 072348 TWDAT TROPICAL WEATHER DISCUSSION NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL 805 PM EDT FRI JUL 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 1800 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 2315 UTC. ...TROPICAL WAVES... TROPICAL WAVE IS ALONG 48W S OF 13N MOVING W 15 KT. BROAD LOW LEVEL CURVATURE IS OBSERVED ON SATELLITE IMAGERY. SCATTERED MODERATE/ISOLATED STRONG CONVECTION IS BEHIND THE WAVE AXIS FROM 9N-11N BETWEEN 43W-47W. THE GFS MODEL FORECASTS THE WAVE TO AFFECT THE LESSER ANTILLES LATE SATURDAY AND THE EASTERN CARIBBEAN...INCLUDING PUERTO RICO AND THE VIRGIN ISLANDS ON SUNDAY. TROPICAL WAVE IS ALONG 65W S OF 16N MOVING W 15 KT. WEAK LOW LEVEL CURVATURE CAN BARELY BE OBSERVED ON SATELLITE IMAGERY. NO SIGNIFICANT CONVECTION IS NOTED ACROSS THE CARIBBEAN...BUT THE WAVE IS PROBABLY ENHANCING THE SHOWER/TSTM ACTIVITY OVER NORTH-CENTRAL VENEZUELA. TROPICAL WAVE IS INLAND OVER THE YUCATAN PENINSULA AND GUATEMALA ALONG 91W S OF 23N MOVING W 15 KT. CLUSTERS OF MODERATE/ISOLATED STRONG CONVECTION ARE ALONG THE WAVE AXIS FROM 16N-19N. CLOUDINESS AND SHOWERS CONTINUE IN THE NORTHWESTERN CARIBBEAN SEA IN ASSOCIATION WITH THIS WESTWARD-MOVING TROPICAL WAVE. DIFFLUENCE FROM AN UPPER LEVEL LOW IN THE BAY OF CAMPECHE MAY ALSO BE ENHANCING THE CONVECTION. ...ITCZ... ITCZ AXIS IS CENTERED ALONG 12N17W 7N35W 9N47W 9N50W 7N60W. SCATTERED MODERATE/ISOLATED STRONG CONVECTION IS WITHIN 70/90 NM EITHER SIDE OF THE AXIS BETWEEN 29W-35W. ...DISCUSSION... GULF OF MEXICO... DEEP LAYERED TROUGH IS OVER THE E U.S. DIGGING S INTO THE NE GULF. THIS STRONG TROUGH ALONG WITH ABUNDANT TROPICAL MOISTURE IS GENERATING ROUNDS OF HEAVY SHOWERS/TSTM OVER PARTS OF THE FLORIDA PENINSULA. MORE OF THE SAME IS EXPECTED TOMORROW. THE ASSOCIATED SURFACE FRONTAL BOUNDARY LIES ALONG NORTHERN FLORIDA AND THE NORTHERN GULF WATERS. ISOLATED SHOWERS/TSTMS ARE RELATED TO THIS STATIONARY FRONT. WIND VELOCITIES ARE BASICALLY ONLY 10 KT ON BOTH SIDES OF THE FRONT. A TROPICAL WAVE IS OVER THE YUCATAN PENINSULA ALONG 89W MOVING WWD WHILE A SURFACE TROUGH IS OVER THE NW QUADRANT OF THE GULF AND NE MEXICO. THE SURFACE TROUGH AND A DIFFLUENT PATTERN ALOFT ARE SUPPORTING THE DEVELOPMENT OF SCATTERED MODERATE CONVECTION OVER SOUTH TEXAS AND NE MEXICO. WATER VAPOR IMAGERY SHOWS AN UPPER LOW OVER THE BAY OF CAMPECHE. CONSIDERABLE UPPER LEVEL MOISTURE WITH BROKEN CLOUDS COVERS THE MAJORITY OF THE GULF. MOISTURE ASSOCIATED WITH THE FRONTAL BOUNDARY/TROPICAL WAVE WILL CONTINUE TO AFFECT THE GULF...PARTICULARLY THE WESTERN HALF. CARIBBEAN SEA... AN UPPER RIDGE WITH CONSIDERABLE MOISTURE IS OVER CENTRAL AMERICA AND THE W CARIBBEAN WEST OF 80W. AN UPPER LOW IS CENTERED NORTH OF PUERTO RICO WITH AN ELONGATED UPPER TROUGH EXTENDING SWWD ALONG THE MONA PASSAGE AND THE CENTRAL CARIBBEAN. CLOUDINESS AND SCATTERED SHOWERS ASSOCIATED WITH THE UPPER LOW ARE AFFECTING DOMINICAN REPUBLIC AND PUERTO RICO. THIS UPPER LOW IS DRIFTING WEST. TYPICAL TRADEWIND SHOWERS ARE OVER MOST OF THE CENTRAL/EAST CARIBBEAN. MODERATE TO STRONG WINDS WILL CONTINUE TO BLOW ACROSS THE BASIN ON SATURDAY THANKS TO A STRONG RIDGE LOCATED NORTH OF THE AREA. ATLANTIC OCEAN... UPPER RIDGE EXTENDS FROM THE W CARIBBEAN ACROSS CUBA AND THE BAHAMAS TO BEYOND 30N74W. AN UPPER LOW IS NORTH OF PUERTO RICO NEAR 23N65W WITH AN UPPER TROUGH WHICH COVERS THE W/CENTRAL ATLC. ITS AXIS EXTENDS NE/SW INTO THE NE CARIBBEAN THROUGH THE MONA PASSAGE. MOSTLY DRY AIR DOMINATES THE AREA WITH THE EXCEPTION OF A BAND OF MOISTURE THAT THE UPPER LOW IS PULLING ACROSS DOMINICAN REPUBLIC AND PUERTO RICO. AN UPPER HIGH DOMINATES THE E ATLC CENTERED NEAR 22N32W AND COVERS THE AREA FROM 25W-50W. ANOTHER UPPER TROUGH CROSSES THE CANARY ISLANDS TO NEAR 21N23W. AT THE SURFACE...A STATIONARY FRONT ENTERS THE AREA NEAR 32N77W THEN CONTINUES WSW ACROSS NORTHERN FLORIDA. CLUSTERS OF SCATTERED MODERATE CONVECTION ARE AHEAD OF THE FRONTAL BOUNDARY FROM 26N-30N WEST OF 75W. A LARGE 1033 MB HIGH IS OVER THE CENTRAL ATLANTIC NEAR 36N32W. ELY FLOW AND MOSTLY FAIR WEATHER ARE UNDER THE INFLUENCE OF THIS FEATURE. ACCORDING TO THE 07/2100 UTC SAHARAN AIR LAYER FROM CIMSS...AFRICAN DUST IS ALSO NOTED FROM EQ-30N E OF 50W SUPPRESSING CONVECTION. $$ GR