000 AXNT20 KNHC 262343 TWDAT TROPICAL WEATHER DISCUSSION NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL 805 PM EDT WED APR 26 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 4N9W 1N22W 2N51W. SCATTERED MODERATE AND ISOLATED STRONG CONVECTION IS NOTED WITHIN 240 NM EITHER SIDE OF THE AXIS E OF 17W AND WITHIN 300 NM OF AXIS W OF 17W. ...DISCUSSION... GULF OF MEXICO... A SHORTWAVE RIDGE HAS SHIFTED SE OF THE AREA BUT ITS ANTICYCLONIC FLOW STILLS COVERS THE SE GULF WATERS ALOFT. A BAND OF DRY UPPER AIR IS INDICATED WITHIN 90 NM EITHER SIDE OF LINE 26N80W 18N91W. AN UPPER ANTICYCLONE IS OVER OLD MEXICO NEAR 17N106W. THE ENVELOPE OF ITS ANTICYCLONIC FLOW COVERS THE GULF WATERS W OF 88W ADVECTING UPPER MOISTURE ALONG ITS EASTERN FRINGES. A SHORTWAVE TROUGH IS MOVING THROUGH THE NORTHERN WATERS WITH ITS AXIS CURRENTLY ALONG 32N93W 29N96W. THE ASSOCIATED SURFACE COLD FRONT EXTENDS FROM 31N90W TO 26N96W THEN BECOMES ILL DEFINED AS IT LIES NW ALONG THE E SLOPE OF MEXICAN MOUNTAINS TO NEAR 29N102W. AN OUTFLOW BOUNDARY HAS MOVED SE OVER THE N CENTRAL GULF WATERS. DEBRIS MOISTURE FROM THIS CONVECTION IS SPREADING GENERALLY NE IN RESPONSE TO THE PARENT UPPER TROUGH...ROUGHLY COVERING THE WATERS N OF 26N E OF 88W. CARIBBEAN SEA... ALOFT...A SHORTWAVE RIDGE ORIGINATING FROM AN UPPER ANTICYCLONE NEAR 6N66W...EXTENDS NW ALONG 11N72W TO 20N83W. ANTICYCLONIC FLOW DOMINATES THE UPPER LEVELS OF THE CARIBBEAN W OF 66W WHERE THE FLOW BECOMES NEARLY ZONAL. DEBRIS MOISTURE FROM CONVECTION S OF 11N BETWEEN 72W AND 83W CONTINUES TO SPREAD NE ALONG THE PERIPHERY OF THE RIDGE WITH DRY UPPER AIR INDICATED ALONG 15N E OF 74W. ATLANTIC OCEAN... A SHORTWAVE RIDGE EXTENDS N FROM THE CARIBBEAN ALONG 70W WITH ANTICYCLONIC FLOW COVERING THE WATERS S OF 27N W OF 62W WHERE THE UPPER FLOW THEN TURNS CYCLONIC INTO A LONGWAVE TROUGH OVER THE CENTRAL ATLC WITH AXIS N TO S ALONG 50W. UPPER MOISTURE IS SPREADING E OFF THE N FLORIDA COAST N OF 29N TO NEAR 70W ATTM. AN EMBEDDED UPPER CYCLONE IS OBSERVED NEAR 29N45W AND SHIFTING NE WITH TIME. AT THE LOW LEVELS...A STATIONARY FRONT IS DISSIPATING ALONG 32N31W 27N42W 21N60W. OVERCAST MULTILAYERED CLOUDS AND SCATTERED SHOWERS ARE NOTED WITHIN 90 NM OF THE DECAYING FRONT. A SURFACE HIGH 1023 MB IS NEAR 34N48W WITH A RIDGE EXTENDING SW TO THE STRAITS OF FLORIDA. E OF THE FRONT... A RIDGE EXTENDS SW ALONG 32N25W 21N46W. THE E ATLC IS DOMINATED ALOFT BY A LONGWAVE TROUGH WITH AN EMBEDDED CYCLONE NEAR 32N5E TRAILING A TROUGH SW ALONG 25N7W TO 14N21W. ANOTHER CYCLONE IS WELL N OF THE AREA NEAR 41N34W WITH A TROUGH EXTENDING S ALONG 32N35W 26N35W. BETWEEN THE TWO CYCLONES AN ANTICYCLONE IS NEAR 34N14W. A BAND OF DRY UPPER AIR IS NOTED WITHIN 540 NM EITHER SIDE OF LINE 27N6W 12N28W. A BROAD UPPER ANTICYCLONE IS NOTED OVER AFRICA NEAR 12N17E WITH A RIDGE EXTENDING W OFF THE W AFRICAN COAST AT 6N12W. ASSOCIATED UPPER DIFFLUENCE IS ENHANCING ITCZ CONVECTION E OF 16W. $$ NELSON