000 AXNT20 KNHC 222243 TWDAT TROPICAL WEATHER DISCUSSION NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL 805 PM EDT SAT APR 22 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. ...THE ITCZ... ITCZ IS CENTERED ALONG 7N13W 5N20W 3N30W 2N40W 2N50W. A FEW CLUSTERS OF WEAKENING MODERATE CONVECTION IS MAINLY WITHIN 250 NM TO THE N OF THE AXIS BETWEEN 17W-33W. SOME OF THE CONVECTIVE BLOW-UPS ARE BEING SHEARED TO THE NE. SCATTERED SHOWERS AND ISOLATED TSTMS ARE FROM 2N-5N BETWEEN 38W-43W. THE STRONGEST AND MOST ORGANIZED CONVECTION REMAINS OVER LAND ACROSS W AFRICA AND S AMERICA. ...DISCUSSION... THE GULF OF MEXICO... UPPER LEVEL RIDGING EXTENDS NWD FROM AN EPAC ANTICYCLONE ALONG 10N90W 20N93W 30N100W. THE GULF OF MEXICO LIES ON THE E SIDE OF THIS RIDGE AXIS WITH NWLY UPPER LEVEL FLOW AND MODERATE/STRONG SUBSIDENCE ACROSS THE REGION. A DEEP LAYERED TROUGH STRETCHES FROM THE N PLAINS STATES AND DIGS INTO N FLORIDA. A SWLY SUBTROPICAL JET IS ADVECTING A PLUME OF MOISTURE FROM THE EPAC ACROSS MEXICO AND INTO THE S CENTRAL U.S. IN THE LOWER LEVELS...A COLD FRONT CONTINUES TO SLOWLY MOVE SEWARD. AS OF 2100 UTC...THE FRONT IS DRAPED FROM NEAR TALLAHASSEE TO 28N86W THEN DISSIPATING TO 27N93W. STRONG SHOWERS AND TSTMS ARE ALONG THE FRONT FROM THE FL PANHANDLE NWD...BUT VERY LITTLE WEATHER IS OCCURRING ALONG THE FRONT IN THE GULF. A PRE-FRONTAL SQUALL LINE EXISTS FROM NEAR ORLANDO NEWD TO 31N79W. THIS LINE OF TSTMS IS MOVING SEWD INTO THE OPEN ATLC. SWLY SFC WINDS ARE FOUND S OF THE FRONT WITH N WINDS BEHIND THE BNDRY AS 1020 MB HIGH PRES SYSTEM CURRENTLY OVER LOUISIANA BUILDS SEWD. THE COLD FRONT WILL CONTINUE TO MOVE SEWD TONIGHT AND WILL BE E OF THE AREA IN 24 HOURS. WEAK HIGH PRES WILL BE CENTERED IN THE E GULF TOMORROW. THE CARIBBEAN SEA... AN UPPER HIGH CONTINUES TO DRIFT WWD IN THE EPAC OFF THE COAST OF NICARAGUA/COSTA RICA GENERATING UPPER LEVEL WESTERLIES AND PLENTY OF DRY/STABLE AIR ALOFT ACROSS THE AREA. THE DRIEST AIR IS CONTAINED S OF 17N. TRADE WINDS HAVE INCREASED TO 20-30 KT ACROSS THE BASIN E OF 80W DUE TO THE TIGHTENING PRES GRAD BETWEEN A W ATLC HIGH AND COLUMBIAN LOW. STRONG SUBSIDENCE PRODUCED BY THE UPPER HIGH IS CAUSING VERY LITTLE TRADE WIND SHOWERS TO DEVELOP IN THE CARIBBEAN...HOWEVER SHOWERS AND TSTMS CONTINUE FURTHER N ACROSS THE N LEEWARD ISLANDS...PUERTO RICO...HISPANIOLA AND JAMAICA. THIS ACTIVITY IS BEING ENHANCED OVER LAND BY THE LOCAL SEA-BREEZES AND TOPOGRAPHY. SIMILAR SHOWERS AND TSTMS HAVE FORMED OVER PARTS OF MOUNTAINOUS CENTRAL AND S AMERICA. THE UPPER LEVEL WESTERLIES ARE CUTTING OFF AND PREVENTING STRONG TSTMS ACROSS THE GREATER ANTILLES. SIMILAR WEATHER IS EXPECTED IN THE CARIBBEAN TOMORROW. TRADE WINDS WILL REMAIN IN THE 20-30 KT RANGE THRU EARLY MON IN THE S CARIBBEAN. THEREAFTER...THE TRADES WILL WEAKEN AS THE W ATLC HIGH PULLS NEWARD. THE ATLANTIC OCEAN... SOMEWHAT OF A RIDGE/TROUGH/RIDGE/TROUGH PATTERN REMAINS ACROSS THE ATLC BASIN...HOWEVER MANY OF THESE FEATURES COVER THE N PORTION OF THE DISCUSSION AREA. A NARROW RIDGE COVERS THE W ATLC FROM 65W-77W N OF 25N WITH THE UPPER AXIS ALONG 72W. UNDERNEATH THE UPPER RIDGE...A 1026 MB SFC HIGH IS CENTERED NEAR 32N68W. A DEEP-LAYER TROUGH COVERS THE AREA FROM 40W-65W N OF 25N. AN ASSOCIATED SFC COLD FRONT ENTERS THE AREA ALONG 32N45W 27N49W 23N53W. UPPER LEVEL DIFFLUENCE ON THE E SIDE OF THE TROUGH AXIS AND FRONTAL FORCING IS PRODUCING SHOWERS AND TSTMS FROM 20N TO BEYOND 32N BETWEEN 43W-47W. GFS SUGGESTS THAT FRONT WILL BEGIN TO WEAKEN AND PULL NWD SUN NIGHT AS ITS UPPER LEVEL SUPPORT TRACKS NEWD AND FLATTENS. THE FRONT WILL BE LOCATED ALONG 32N43W 24N54W IN 24 HOURS. FARTHER EAST...SFC RIDGING DOMINATES THE E ATLC WITH A 1030 MB HIGH CENTERED NEAR 38N29W. IN THE UPPER LEVELS...AN AMPLIFIED NARROW RIDGE AXIS EXTENDS FROM 22N39W TO BEYOND 32N34W WITH UPPER TROUGHING COVERING THE AREA E OF 20W. STRONG SUBSIDENCE ENHANCED BY UPPER LEVEL CONFLUENT FLOW IS WIDESPREAD FROM 15N-30N E OF 32W. $$ CANGIALOSI