000 AXNT20 KNHC 071714 TWDAT TROPICAL WEATHER DISCUSSION NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL 205 PM EDT FRI APR 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 1645 UTC. ...THE ITCZ... ITCZ AXIS IS CENTERED ALONG 1310N13W 4N22W 4N40W 1N50W. SCATTERED MODERATE CONVECTION WITHIN 90 NM EITHER SIDE OF AXIS 18W-23W AND FROM 43W-52W ...DISCUSSION... GULF OF MEXICO... HIGH AMPLITUDE MIDDLE TO UPPER LEVEL RIDGE CONTINUES TO DOMINATE THE GULF WITH THE RIDGE CURRENTLY EXTENDING FROM THE YUCATAN PENINSULA NEWD OVER FLORIDA AND ALONG THE E COAST OF THE U.S. THE RIDGE IS GRADUALLY BEING PUSHED EWD BY A PROGRESSIVE TROUGH ADVANCING THROUGH THE CENTRAL U.S. WATER VAPOR IMAGERY SHOWS CONFLUENT FLOW AND SUBSIDENCE WITH ASSOCIATED DRY/STABLE AIR ALOFT OVER ALL BUT THE NW GULF WHERE SOME HIGH LEVEL CLOUDS ACCOMPANY A 60-90 KT JET ALONG THE N GULF COAST. THE UPPER TROUGH WILL CONTINUE TO ADVANCE EWD OVER THE E U.S. DURING THE NEXT 2 DAYS WITH THE ATTENDANT SURFACE COLD FRONT ENTERING THE NW GULF EARLY SAT. THE FRONT WILL INITIALLY LACK APPRECIABLE MOISTURE AND DYNAMICS EARLY SAT BUT LOW-LEVEL MOISTURE POOLING AND A SHARPENING UPPER PATTERN WILL ALLOW INCREASING SHOWERS/TSTMS ALONG THE FRONT LATE SAT INTO SUN AS THE FRONT PUSHES OVER THE E GULF AND FLORIDA. THE REMAINDER OF THE AREA WILL REMAIN ESSENTIALLY DRY AS POST-FRONTAL HIGH PRES AND ASSOCIATED STABLE AIR PUSHES SWD. CARIBBEAN SEA... MIDDLE TO UPPER LEVEL RIDGE EXTENDS FROM THE YUCATAN PENINSULA NEWD OVER FLORIDA WITH A TROUGH FURTHER E OVER THE E CARIBBEAN FROM PUERTO RICO TO PANAMA. CONFLUENT FLOW BETWEEN THESE TWO FEATURES IS PRODUCING STRONG SUBSIDENCE AND VERY DRY/STABLE CONDITIONS ALOFT OVER THE CARIBBEAN WATERS AND CENTRAL AMERICA W OF THE TROUGH AXIS. E OF THE TROUGH AXIS...A 60-10 KT SUBTROPICAL JET EXTENDS FROM THE E CARIBBEAN NEWD OVER THE LEEWARD ISLANDS AND INTO THE CENTRAL ATLANTIC. A BAND OF HIGH CLOUDINESS ACCOMPANIES THE JET COVERING MUCH OF THE SE CARIBBEAN AND ALL OF THE LESSER ANTILLES. AT THE LOWER LEVELS...THE REMNANTS OF AN OLD FRONTAL BOUNDARY OVER THE NE CARIBBEAN CONTINUES TO PRODUCE SCATTERED SHOWERS AND A FEW ISOLATED TSTMS GENERALLY N OF 15N E OF 70W. THIS ACTIVITY IS EXPECTED GRADUALLY SUBSIDE OVER THE NEXT 24 HRS AS THE UPPER TROUGH LIFTS NEWD PRODUCING A MORE CONFLUENT/STABLE PATTERN ALOFT BY LATE SAT. ATLANTIC... A MIDDLE TO UPPER LEVEL RIDGE HAS PUSHED OFF THE E COAST OF THE U.S. DURING THE LAST 24 HOUR AND NOW LIES OVER THE W ATLC FROM FLORIDA NEWD IN BETWEEN THE E COAST OF THE U.S. AND BERMUDA. UPSTREAM MOISTURE IS RIDING UP AND OVER THE RIDGE MAINTAINING GENERALLY DRY/TRANQUIL CONDITIONS OVER THE W ATLC. SHIFTING E...A SHARP MIDDLE TO UPPER LEVEL TROUGH OVER THE CENTRAL ATLC EXTENDS FROM 32N55W SWD INTO THE E CARIBBEAN. CONFLUENT FLOW ON THE BACKSIDE OF THE TROUGH AXIS IS PRODUCING A LARGE AREA OF SUBSIDENCE AND DRY/STABLE AIR ALOFT OVER THE W ATLC TO THE AFOREMENTIONED RIDGE AXIS. DYNAMICS/LIFT E OF THE UPPER TROUGH AXIS CONTINUES TO SUPPORT CLOUDINESS AND SCATTERED SHOWERS/TSTMS WITHIN 150 NM EITHER SIDE OF 50W N OF 20N. THE UPPER TROUGH WILL CONTINUE TO BE PROGRESSIVE OVER THE NEXT 24 HRS WITH THE BULK OF THE ACTIVITY BEING FOCUSED BETWEEN 40W-50W TOMORROW. OVER THE E ATLANTIC...A PERSISTENT TROUGH REMAINS N OF 15N E OF 35W. THE ATTENDANT COLD FRONT...NOW WEAKENING...EXTENDS FROM 32N23W TO 27N33W WITH SCATTERED SHOWERS WITHIN 75 NM EITHER SIDE OF BOUNDARY. FINALLY...SOME AFRICAN DUST IS FAINTLY VISIBLE IN SATELLITE IMAGERY S OF 15N AND E OF 50W. $$ RHOME