000 AXNT20 KNHC 170456 TWDAT TROPICAL WEATHER DISCUSSION NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL 205 AM EDT SAT MAY 17 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 31W S OF 10N 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 52W S OF 11N MOVING W 5-10 KT. WAVE SIGNATURE IS DISTORTED AS THE WAVE MOVES INLAND OVER SOUTH AMERICA WITH NO ASSOCIATED SHOWERS/CONVECTION. TROPICAL WAVE IN THE SW CARIBBEAN ALONG 77W S OF 11N MOVING W 10-15 KT. NO WAVE SIGNATURE IS OBSERVED. SCATTERED MODERATE/ ISOLATED STRONG CONVECTION IS INLAND AND ALONG THE IMMEDIATE COAST OF COLOMBIA AND PANAMA WITHIN 30 NM OF THE WAVE AXIS. ..THE ITCZ... ITCZ AXIS IS CENTERED ALONG 6N9W 5N13W 6N20W 6N28W 1N39W 6N50W. NUMEROUS STRONG CONVECTION IS N OF 3N TO INLAND OVER THE IVORY COAST OF AFRICA BETWEEN 4W-8W ALONG THE BORDER OF LIBERIA AND WITHIN 60 NM N OF THE ITCZ AXIS FROM 11W-14W. SCATTERED MODERATE/STRONG CONVECTION COVERS THE REMAINDER OF THE AREA FROM 4N-9N BETWEEN 10W-15W. CLUSTERS OF SIMILAR CONVECTION ARE FROM THE COAST OF SW AFRICA TO S OF THE EQUATOR BETWEEN 3W-12W. CLUSTERS OF SCATTERED MODERATE/ISOLATED STRONG CONVECTION ARE WITHIN 150 NM OF LINE FROM 8N32W TO 2N47W. SCATTERED CLUSTERS OF SCATTERED MODERATE CONVECTION ARE WITHIN 150 NM OF THE ITCZ AXIS BETWEEN 16W-29W. ...DISCUSSION... GULF OF MEXICO... A MODERATE COLD FRONT EXTENDS ALONG THE SE US COAST THROUGH A WEAK 1012 MB LOW OVER THE W FLORIDA PANHANDLE WEAKENING AS IT ENTERS THE GULF EXTENDING SW INTO MEXICO NEAR TUXPAN. THE UPPER LEVEL TROUGH AND THUS THE SUPPORT FOR THIS FRONT IS WELL N OF THE AREA. THE UPPER LEVELS OF THE GULF ARE DOMINATED BY A A BROAD UPPER RIDGE ANCHORED IN THE CARIBBEAN AND COVER THE W ATLC AS WELL. HEAVY SHOWERS AND THUNDERSTORMS ARE INLAND OVER MEXICO EXTENDING FROM THE ISTHMUS OF TEHUANTEPEC NW OVER MEXICO CITY THEN N TO MONTERREY. DEBRIS CLOUDS AND POSSIBLE ISOLATED SHOWERS ARE BEING DRAWN OVER THE W GULF BY THE UPPER LEVEL FLOW WITHIN 75 NM OF THE COASTLINE THE CENTRAL BAY OF CAMPECHE TO TEXAS NEAR HOUSTON. OTHERWISE SCATTERED LOW CLOUDS ARE W OF THE FRONT WHILE THE REMAINDER OF THE GULF IS CLOUD FREE. HOWEVER...SMOKE COVERS THE E GULF AHEAD OF THE FRONT AS A RESULT OF EARLIER FIRES OVER MEXICO AND THE YUCATAN. CARIBBEAN SEA... BROAD UPPER RIDGE IS ANCHORED OVER NEAR THE CAYMAN ISLANDS AND COVERS THE CARIBBEAN W OF 65W AND EXTENDS OVER THE GULF OF MEXICO AND THE W ATLC. THIS IS PRODUCING STRONG SUBSIDENCE AND DRY STABLE AIR OVER MOST OF THE AREA THUS LIMITING ANY DEEP CONVECTION. THE REMNANTS OF A FRONTAL BOUNDARY WITH SCATTERED SHOWERS EXTENDS WITHIN 75 NM OF A LINE FROM THE VIRGIN ISLANDS ACROSS PUERTO RICO...S HISPANIOLA...JAMAICA TO NEAR 18N80W. WESTERLY UPPER FLOW AND THUS HIGH CLOUDS COVERS THE S CARIBBEAN S OF A LINE FROM CENTRAL NICARAGUA ALONG N COLOMBIA AND THE ABC ISLANDS THEN NE OVER THE LESSER ANTILLES JUST S OF GUADELOUPE. ATLANTIC OCEAN... DEEP LAYERED RIDGE COVERS THE THE W ATLC WITH THE UPPER RIDGE ANCHORED IN THE CARIBBEAN AND THE SURFACE RIDGE ANCHORED BY A 1018 MB HIGH NEAR 28N64W. DEEP LAYERED TROUGH IS IN THE CENTRAL ATLC WITH THE UPPER TROUGH N OF 22N BETWEEN 43W-55W AND THE WEAKENING COLD FRONT ENTERING THE REGION NEAR 32N48W TO 22N55W BECOMING NEAR STATIONARY AND DISSIPATING TO OVER THE VIRGIN ISLANDS. SCATTERED SHOWERS/ISOLATED THUNDERSTORMS ARE WELL E OF THE FRONT AND ARE MORE ASSOCIATED WITH THE UPPER LEVELS FROM 23N-32N BETWEEN 44W-48W. THE REMAINDER OF THE ATLC IS UNDER ZONAL WESTERLY FLOW. A SURFACE RIDGE DOMINATES THE REMAINDER OF THE ATLC N OF 12N E OF THE CENTRAL ATLC FRONT WITH A 1026 MB HIGH CENTERED SW OF THE AZORES NEAR 34N33W AND THUS FAIR WEATHER CLOUDS ARE ALL THAT ARE PRESENT. $$ WALLACE