000 AXNT20 KNHC 181025 TWDAT TROPICAL WEATHER DISCUSSION NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL 805 AM EDT SUN MAY 18 2008 TROPICAL WEATHER DISCUSSION FOR NORTH AMERICA...CENTRAL AMERICA...THE GULF OF MEXICO...THE CARIBBEAN SEA...NORTHERN 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...METEOROLOGICAL ANALYSIS...WEATHER OBSERVATIONS...AND RADAR. BASED ON 0600 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 0945 UTC. ...TROPICAL WAVES... TROPICAL WAVE IS ALONG 37W/38W S OF 10N MOVING W 10-15 KT. INVERTED-V CURVATURE IS OBSERVED ON SATELLITE IMAGERY. ANY SHOWERS/CONVECTION ARE ASSOCIATED WITH THE ITCZ. TROPICAL WAVE IS ALONG 587W S OF 10N MOVING W 10 KT. WAVE SIGNATURE REMAINS DISTORTED AS IT CONTINUES ACROSS SOUTH AMERICA WITH ANY SHOWER ACTIVITY INLAND OVER GUYANA. TROPICAL WAVE IN THE SW CARIBBEAN ALONG 81W/82W S OF 10N MOVING W NEAR 10 KT. WAVE SIGNATURE IS OBSERVED IN THE E PACIFIC REGION. SCATTERED SHOWERS/ISOLATED THUNDERSTORMS ARE S OF 10N TO INLAND OVER PANAMA BETWEEN 77W-82W. ..THE ITCZ... ITCZ AXIS IS CENTERED ALONG 4N8W 3N15W 5N26W 6N39W 4N51W. CLUSTERS OF SCATTERED MODERATE/STRONG CONVECTION ARE BETWEEN THE SW COAST OF AFRICA AND THE EQUATOR E OF 10W ACROSS THE PRIME MERIDIAN. SCATTERED MODERATE/ISOLATED STRONG CONVECTION IS WITHIN 75 NM OF THE ITCZ AXIS FROM 44W-50W AND FROM 1N-4N BETWEEN 16W-21W. CLUSTERS OF SCATTERED MODERATE CONVECTION ARE FROM 8N TO THE EQUATOR BETWEEN 21W-38W. ...DISCUSSION... GULF OF MEXICO... A WEAK STATIONARY BOUNDARY REMAINS ACROSS THE GULF ENTERING THE REGION ACROSS CENTRAL FLORIDA JUST N OF LAKE OKEECHOBEE ALONG 26N91W THEN S INTO THE BAY OF CAMPECHE AND THE COAST OF MEXICO NEAR COATZACOALCOS. THE ASSOCIATED UPPER TROUGH IS OVER THE NW ATLC WHILE A SECOND UPPER LOW IS MOVING ACROSS TEXAS WITH AN UPPER TROUGH EXTENDING S OVER MEXICO AND A RE-ENFORCING SHORTWAVE IS MOVING ACROSS THE LOWER MISSISSIPPI VALLEY. THE UPPER LEVELS OF THE GULF REMAIN DOMINATED BY A BROAD UPPER RIDGE ANCHORED IN THE CARIBBEAN THAT ALSO COVERS THE W ATLC. SCATTERED SHOWERS/THUNDERSTORMS ARE OVER THE W GULF S OF 27N W OF 94W TO INLAND OVER MEXICO WITH SCATTERED SHOWERS/ISOLATED THUNDERSTORMS WITHIN 90 NM N OF THE FRONT E OF 94W. THIS ACTIVITY IS MOVING E BY THE UPPER LEVEL FLOW. SMOKE CONTINUES TO PLAGUE PORTIONS OF THE GULF AS A RESULT OF FIRES THAT WHERE OVER THE YUCATAN PENINSULA. CARIBBEAN SEA... BROAD UPPER RIDGE IS ANCHORED BETWEEN JAMAICA AND THE CAYMAN ISLANDS COVERING MOST OF THE CARIBBEAN...THE GULF OF MEXICO AND THE W ATLC. WESTERLY UPPER FLOW AND THUS HIGH CLOUDS COVERS THE S CARIBBEAN S OF A LINE FROM THE N COAST OF HONDURAS SE TO THE ABC ISLANDS THEN NE OVER THE LESSER ANTILLES JUST S OF GUADELOUPE. THE AREA N OF THIS IS LINE HAS STRONG SUBSIDENCE AND DRY STABLE AIR THUS LIMITING ANY DEEP CONVECTION. SKIES ARE CLEAR ACROSS THE N CARIBBEAN WITH THE ONLY SHOWER ACTIVITY IS ASSOCIATED WITH THE TROPICAL WAVE ALONG 81W/82W. ATLANTIC OCEAN... UPPER TROUGH IS OVER THE NW ATLC N OF 30N W OF 50W WITH THE ASSOCIATED COLD FRONT ENTERING THE REGION E OF BERMUDA NEAR 32N62W EXTENDING TO 29N71W BECOMING STATIONARY INTO THE GULF ACROSS CENTRAL FLORIDA JUST N OF LAKE OKEECHOBEE. BROAD UPPER RIDGE COVERS THE W ATLC INTO THE CENTRAL ATLC ANCHORED IN THE CARIBBEAN. A NARROW DEEP LAYERED TROUGH IS IN THE E/CENTRAL ATLC WITH THE UPPER TROUGH N OF 17N BETWEEN 36W-50W AND A DISSIPATING COLD FRONT ENTERING THE REGION NEAR 32N43W ALONG 24N50W TO 21N60W WITH NO SIGNIFICANT WEATHER ASSOCIATED WITH THE REMNANT S OF THE FRONT. THE REMAINDER OF THE ATLC IS UNDER ZONAL WESTERLY FLOW WITH AN UPPER TROUGH DIPPING S JUST E THE CANARY ISLANDS. A SURFACE RIDGE DOMINATES THE ATLC N OF 15N E OF 70W BRIDGING THE EASTERN MOST FRONT AND ANCHORED BY A 1026 MB HIGH CENTERED S OF THE AZORES NEAR 35N28W AND A WEAK 1019 MB HIGH W OF THE FRONT NEAR 26N55W. $$ WALLACE