000 AXNT20 KNHC 180501 TWDAT TROPICAL WEATHER DISCUSSION NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL 205 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 0000 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 0415 UTC. ...TROPICAL WAVES... TROPICAL WAVE IS ALONG 35W S OF 9N MOVING W 10 KT. WEAK INVERTED-V CURVATURE IS OBSERVED ON SATELLITE IMAGERY. ANY SHOWERS/CONVECTION ARE ASSOCIATED WITH THE ITCZ. TROPICAL WAVE IS ALONG 57W S OF 10N MOVING W 10 KT. WAVE SIGNATURE REMAINS DISTORTED AS IT CONTINUES OVER SOUTH AMERICA WITH ISOLATED SHOWERS S OF 10N FROM 55W-58W. TROPICAL WAVE IN THE SW CARIBBEAN ALONG 80W S OF 10N MOVING W 5-10 KT. WAVE SIGNATURE IS OBSCURED DUE TO HIGH CLOUDS. HOWEVER...THE PRECIPITABLE WATER IMAGERY DOES INDICATED THE PRESENCE OF A WAVE. SCATTERED SHOWERS/ISOLATED THUNDERSTORMS ARE INLAND AND ALONG THE IMMEDIATE COAST OF PANAMA BETWEEN 77W-80W. ..THE ITCZ... ITCZ AXIS IS CENTERED ALONG 7N8W 4N17W 5N27W 3N41W 1N51W. SCATTERED MODERATE/STRONG CONVECTION IS FROM 1N-5N BETWEEN 15W-18W AND FROM 1N-7N BETWEEN 22W26W. CLUSTERS OF SIMILAR CONVECTION ARE BETWEEN THE EQUATOR AND THE SW COAST OF AFRICA E 10W ACROSS THE PRIME MERIDIAN. SMALL CLUSTERS OF SCATTERED MODERATE/ISOLATED STRONG CONVECTION ARE WITHIN 250 NM S OF THE ITCZ AXIS FROM 26W-32W AND WITHIN 200 NM N OF THE ITCZ AXIS FROM W OF 26W ACROSS THE REMAINDER OF THE ATLC TO INLAND OVER SOUTH AMERICA. ...DISCUSSION... GULF OF MEXICO... A WEAK STATIONARY BOUNDARY REMAINS ACROSS THE GULF ENTERING THE REGION ACROSS CENTRAL FLORIDA JUST N OF LAKE OKEECHOBEE ALONG 25N91W THEN S INTO THE BAY OF CAMPECHE AND THE COAST OF MEXICO NEAR COATZACOALCOS. THE INITIAL UPPER TROUGH HAS MOVED OVER THE NW ATLC WHILE AN UPPER LOW IS MOVING ACROSS W TEXAS WITH AN UPPER TROUGH EXTENDING S OVER W MEXICO AND A RE-ENFORCING SHORTWAVE IS MOVING TO OVER THE LOWER MISSISSIPPI VALLEY. THE UPPER LEVELS OF THE GULF REMAIN DOMINATED BY A BROAD UPPER RIDGE ANCHORED IN THE CARIBBEAN AND ALSO COVERS THE W ATLC. SCATTERED SHOWERS/ISOLATED THUNDERSTORMS ARE INLAND OVER S AND E MEXICO MOVING INTO THE SW GULF BY THE UPPER LEVEL FLOW WITHIN 125 NM ALONG THE COAST FROM THE E BAY OF CAMPECHE TO JUST S OF THE TEXAS BORDER. SMOKE CONTINUES TO PLAGUE PORTIONS OF THE GULF AS A RESULT OF FIRES THAT WHERE OVER THE YUCATAN. CARIBBEAN SEA... BROAD UPPER RIDGE IS ANCHORED JUST W OF JAMAICA AND COVERS 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 GULF OF HONDURAS ALONG 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 80W. ATLANTIC OCEAN... UPPER TROUGH HAS MOVED OFF THE NE US COVERING THE NW ATLC N OF 30N W OF 55W WITH THE ASSOCIATED COLD FRONT ENTERING THE REGION OVER BERMUDA EXTENDING TO THE E COAST OF CENTRAL FLORIDA NEAR VERO BEACH BECOMING STATIONARY INTO THE GULF JUST N OF LAKE OKEECHOBEE. BROAD UPPER RIDGE COVERS THE W ATLC ANCHORED IN THE CARIBBEAN. A NARROW DEEP LAYERED TROUGH IS IN THE CENTRAL ATLC WITH THE UPPER TROUGH N OF 18N BETWEEN 36W-55W AND A WEAK COLD FRONT ENTERING THE REGION NEAR 32N44W ALONG 24N50W TO 21N60W. A NARROW UPPER RIDGE IS JUST TO THE E PROVIDING UPPER LEVEL DIFFLUENCE TO GENERATE SCATTERED SHOWERS AND POSSIBLE ISOLATED THUNDERSTORMS WITHIN 150/200 NM OF LINE FROM 24N43W TO 33N38W. THE REMAINDER OF THE ATLC IS UNDER ZONAL WESTERLY FLOW WITH AN UPPER TROUGH DIPPING S TO OVER 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 35N27W. $$ WALLACE