000 AXNT20 KNHC 232345 TWDAT TROPICAL WEATHER DISCUSSION NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL 805 PM EDT SUN APR 23 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. ...ITCZ... ITCZ AXIS IS CENTERED ALONG 6N10W 2N30W2N50. ISOLATED MODERATE AND STRONG CONVECTION IS NOTED WITHIN 90 NM N AND WITHIN 360 NM S OF THE AXIS E OF 20W AND WITHIN 180 NM EITHER SIDE OF THE AXIS W OF 30W. ...DISCUSSION... GULF OF MEXICO... ALOFT...A SHORTWAVE RIDGE DOMINATES THE GULF OF MEXICO AND CONTINUES N ACROSS THE CENTRAL CONUS WITH AXIS ROUGHLY ALONG 94W. UPPER DIFFLUENCE ENHANCED CONVECTION OVER OLD MEXICO WITHIN 120 NM EITHER SIDE OF LINE 19N100W 28N100W. THE RESULTANT DEBRIS MOISTURE IS ADVECTED NNE ACROSS SE TEXAS THEN SPILLS E ACROSS THE UPPER RIDGE...ALL W OF A LINE ALONG 22N95W 27N95W 29N88W. ELSEWHERE THE UPPER LEVELS ARE DOMINATED BY DRY AIR WITH THE ASSOCIATED SUBSIDENCE SUPPRESSING CONVECTION EXCEPT FOR A SMALL CLUSTER NEAR 26.5N86.5W ASSOCIATED WITH A SURFACE FRONT THAT HAS STALLED FROM CENTRAL FLORIDA TO 27N90W. THE FRONTAL BOUNDARY IS NOW DRIFTING SLOWLY N AS A WEAK WARM FRONT FROM 27N90W TO 28N95W. TO THE N OF THE FRONT A HIGH PRES 1017 MB IS NEAR 29N85W. CARIBBEAN SEA... ALOFT...A SHORTWAVE TROUGH EXTENDS SW ACROSS THE W CARIBBEAN WITH ITS MEAN AXIS ALONG 21N76W 16N82W 11N85W. THE ASSOCIATED UPPER DIFFLUENCE ENHANCED SEABREEZE CONVECTION OVER E CUBA AND HISPANIOLA AND JAMAICA AND OVER CENTRAL AMERICA BETWEEN 93W AND 83W THIS AFTERNOON. TO THE E OF THE TROUGH A BROAD RIDGE IS NOTED WITH DRY AIR SUPPRESSING CONVECTION. THE ATLANTIC RIDGE TO THE N IS MAINTAINING EASTERLY TRADES WITH THE GRADIENT STRONGEST S OF 15N BETWEEN 75W AND 65W. ATLANTIC OCEAN... A SHORTWAVE TROUGH DOMINATES THE UPPER LEVELS OF THE WESTERN N ATLC WITH ITS AXIS ROUGHLY ALONG 32N75W 21N76W WITH A SMALL UPPER VORTEX NOTED NEAR 29N73W. IMMEDIATELY TO THE E...A SHORTWAVE RIDGE EXTENDS N FROM A SMALL ANTICYCLONE NEAR 8N56W AND COVERS THE DISCUSSION AREA BETWEEN 68W AND 38W WITH THE UPPER FLOW VERY DRY AND MOSTLY ZONAL IN THE SAME AREA. A THIN UPPER MOISTURE PLUME ORIGINATING FROM CONVECTION OVER CUBA AND HISPANIOLA IS NOTED WITHIN 120 NM OF LINE 20N70W 24N50W. CONVECTION WAS ALSO ENHANCED OVER THE SOUTHERN BAHAMAS NEAR 22N72W WITH THE DEBRIS MOISTURE SPREADING E TO NEAR 23N68W WHERE IT EVAPORATES IN THE DRY UPPER AIR. AT THE LOW LEVELS...A STATIONARY FRONT EXTENDS ACROSS THE NW ATLC WATERS FROM 32N76W TO THE FLORIDA E COAST AT 28N. LOCALLY BROKEN LOW AND MID LAYERED CLOUDS WITH A FEW SHOWERS ARE NOTED WITHIN 90 NM E AND SE OF THE FRONT. HIGH PRES 1026 MB IS NEAR BERMUDA RIDGING SW TO THE NW BAHAMAS. TO THE E...ANOTHER STATIONARY FRONT LIES ALONG 31N43W 21N58W WITH SCATTERED SHOWERS NOTED WITHIN 60 NM OF THE FRONT. STILL FURTHER E...HIGH PRES NEAR THE AZORES RIDGES SW ALONG 32N32W TO TO 24N45W. THE E ATLC IS DOMINATED ALOFT BY A LONGWAVE TROUGH WITH AN EMBEDDED CYCLONE NEAR 32N7W TRAILING A TROUGH SW ALONG 32N8W 22N20W 14N35W. A BAND OF DRY UPPER AIR IS NOTED WITHIN 90 NM EITHER SIDE OF LINE 32N1E 25N6W 22N14W THEN THE DRY AIR WIDENS COVERING THE DISCUSSION AREA FROM 12N TO 28N BETWEEN 30W AND 20W. UPPER MOISTURE IS INDICATED N OF THE DRY BAND AND IS MOVING ACROSS AFRICA TO THE N OF 26N W OF 3W. A BROAD UPPER ANTICYCLONE IS NOTED OVER AFRICA NEAR 15N7E WITH A RIDGE EXTENDING W OFF THE W AFRICAN COAST AT 6N11W TO A SHARP CREST AT 4N32W. UPPER DIFFLUENCE IS ENHANCING ITCZ CONVECTION DESCRIBED ABOVE. $$ NELSON