000 AXNT20 KNHC 282355 TWDAT TROPICAL WEATHER DISCUSSION NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL 805 PM EDT MON JUL 28 2008 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...METEOROLOGICAL ANALYSIS...WEATHER OBSERVATIONS...AND RADAR. BASED ON 1800 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 2315 UTC. ...TROPICAL WAVES... A TROPICAL WAVE IS MOVING OFF THE WEST COAST OF AFRICA WITH A 1009 MB LOW LOCATED NEAR 10N14W. THIS LOW SHOWS SOME SIGNS OF ORGANIZATION. SOME SLOW DEVELOPMENT OF THIS SYSTEM IS POSSIBLE OVER THE NEXT COUPLE OF DAYS AS THE WAVE MOVES TO THE WNW AT ABOUT 15 MPH. SATELLITE IMAGERY SHOWS THE CLOUD PATTERN EXHIBITING CYCLONIC CIRCULATION DUE TO THE PRESENCE OF THE LOW PRES. THIS WAVE WILL BE ADDED TO THE 00Z SFC MAP. A HIGH AMPLITUDE TROPICAL WAVE EXTENDS FROM 20N40W TO 5N43W MOVING WEST ABOUT 20 KT. INVERTED-V LOW LEVEL SIGNATURE IS OBSERVED ON SATELLITE IMAGERY WITH MAINLY LOW/MID CLOUDS. NO DEEP CONVECTIVE PRECIPITATION ACCOMPANIES THIS FEATURE. THIS WAVE WILL ENTER THE TROPICAL N ATLC WATERS ON WED. A TROPICAL WAVE HAS ENTERED THE E CARIBBEAN. ITS AXIS EXTENDS FROM THE N LEEWARD ISLANDS TO NE VENEZUELA ALONG 62W MOVING WEST NEAR 20 KT. THE SAHARAN AIR LAYER FROM CIMSS SHOWS AN AREA OF AFRICAN DUST JUST BEHIND THE WAVE AXIS. SCATTERED MODERATE CONVECTION IS FROM 11N-15N BETWEEN 60W-64W. THIS ACTIVITY IS AFFECTING THE WINDWARD ISLANDS. MOISTURE ASSOCIATED WITH THIS TROPICAL WAVE WILL REMAIN SOUTH OF PUERTO RICO/HISPANIOLA. A TROPICAL WAVE IS MOVING WWD ACROSS THE YUCATAN PENINSULA AND NORTHERN CENTRAL AMERICA GENERATING SOME SHOWER ACTIVITY. THIS WAVE CONTINUES TO THE E PACIFIC. ...THE ITCZ... THE ITCZ AXIS IS CENTERED ALONG 9N15W 10N29W 14N39W 9N50W 12N60W. BESIDES THE CONVECTION MENTIONED IN THE TROPICAL WAVE SECTION...SCATTERED MODERATE CONVECTION IS NEAR 9N26W...AND FROM 6N-8N BETWEEN 48W-52W. ...DISCUSSION... THE GULF OF MEXICO... SHOWER AND THUNDERSTORM ACTIVITY OVER THE NORTH-CENTRAL GULF OF MEXICO IS ASSOCIATED WITH A WEAK SURFACE TROUGH OF LOW PRESSURE THAT RUNS FROM 31N88W TO 25N90W. UPPER-LEVEL WINDS ARE FORECAST TO BE UNFAVORABLE FOR SIGNIFICANT DEVELOPMENT OF THIS SYSTEM AS IT MOVES SLOWLY NORTH-NORTHWESTWARD OVER THE NEXT DAY OR TWO... LEAVING A HIGH PRES RIDGE ACROSS THE CENTRAL GULF. SCATTERED MODERATE CONVECTION IS FROM 26N-29N BETWEEN 87W-90W. A DIFFLUENT PATTERN ALOFT ASSOCIATED WITH AN UPPER-LEVEL HIGH LOCATED OVER THE N-CENTRAL GULF WATERS IS ENHANCING THIS ACTIVITY. THIS UPPER-LEVEL FEATURE DOMINATES THE ENTIRE GULF AND THE STATE OF FLORIDA WHERE IS ALSO ASSISTING IN THE DEVELOPMENT OF SHOWERS AND TSTMS. A WEAK 1015 MB HIGH REMAINS OVER THE W GULF OF MEXICO NEAR 27N93W PRODUCING MOSTLY FAIR WEATHER W OF 90W. MAINLY LIGHT AND VARIABLE WINDS ARE NOTED THROUGHOUT THE GULF REGION. THE CARIBBEAN SEA... AN UPPER-LEVEL LOW IS SPINNING BETWEEN E CUBA AND JAMAICA. UPPER DIFFLUENCE BETWEEN THIS LOW AND THE UPPER HIGH SITUATED OVER THE GULF OF MEXICO IS HELPING TO INDUCE SCATTERED SHOWERS AND TSTMS OVER PARTS OF CUBA...THE CAYMAN ISLANDS AND THE NW CARIBBEAN. AN UPPER-LEVEL RIDGE WITH AXIS EXTENDING OVER NORTHERN SOUTH AMERICA COVERS THE REMAINDER OF THE BASIN. THE COLOMBIAN OR PANAMANIAN LOW IS GENERATING SOME SHOWER ACTIVITY OVER THE SW CARIBBEAN WHILE A TROPICAL WAVE IS MOVING WWD ACROSS THE EASTERN PORTION OF THE CARIBBEAN SEA. SEE TROPICAL WAVE SECTION. MODERATE TO STRONG TRADE WINDS OF 20 TO 25 KT ARE BLOWING ACROSS THE AREA DUE TO THE PRES GRADIENT BETWEEN THE COLOMBIAN LOW AND THE ATLANTIC RIDGE. THE ATLANTIC OCEAN... THE BERMUDA-AZORES HIGH...A LARGE SUBTROPICAL SEMI-PERMANENT CENTER OF HIGH ATMOSPHERIC PRESSURE FOUND NEAR THE AZORES IN THE ATLC OCEAN...DOMINATES THE ATLANTIC FORECAST AREA WITH A RIDGE EXTENDING SW TO SOUTH FLORIDA AND CUBA. A SMALL SURFACE TROUGH IS OVER THE CENTRAL ATLANTIC AND GOES FROM 29N51W TO 24N56W. ISOLATED SHOWERS ARE WITHIN 30 NM OF THE TROUGH AXIS. ALOFT...AN UPPER-LEVEL TROUGH ENTERS THE REGION NEAR 31N62W THEN CONTINUES SW TO THE UPPER-LEVEL LOW LOCATED BETWEEN E CUBA AND JAMAICA. NE TO E WINDS W OF THE TROUGH ARE DRAWING A FAIR AMOUNT OF UPPER LEVEL MOISTURE ACROSS THE W ATLC INTO FLORIDA AND THE BAHAMAS. FURTHER EAST...A LARGE UPPER LEVEL HIGH IS CENTERED OVER THE E-CENTRAL ATLANTIC NEAR 18N39W PRODUCING MODERATE TO STRONG SUBSIDENCE. ANOTHER UPPER-LEVEL TROUGH IS OVER THE E ATLC ALONG 22W/23W WITH THE BASE OF THE TROUGH REACHING 23N. MAINLY ELY WINDS DOMINATES THE TROPICS. $$ GR