000 AXNT20 KNHC 242315 TWDAT TROPICAL WEATHER DISCUSSION... NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL 805 PM EDT THU APR 24 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 1800 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH WWWW UTC. ...THE ITCZ... ITCZ AXIS IS CENTERED ALONG 4N6W 3N16W 2N30W THEN ALONG THE EQUATOR FROM 40W-52W. CLUSTERS OF SCATTERED MODERATE/STRONG CONVECTION ARE S OF THE EQUATOR TO INLAND OVER SW AFRICA BETWEEN 5W-10W AND WITHIN 60 NM OF THE ITCZ AXIS BETWEEN 10W-14W. SCATTERED CLUSTERS OF SCATTERED MODERATE/ISOLATED STRONG CONVECTION ARE WITHIN 120/150 NM OF THE ITCZ AXIS FROM 16W-38W. ...DISCUSSION... GULF OF MEXICO... A BROAD UPPER RIDGE DOMINATES THE MOST OF THE GULF ANCHORED IN THE E PACIFIC REGION WITH THE AXIS EXTENDING ALONG THE COAST OF MEXICO TO OVER E TEXAS. A SURFACE RIDGE EXTENDS FROM OVER THE SE US INTO THE GULF N OF 25N. A BROAD UPPER TROUGH COVERS THE E GULF E OF 86W ACROSS THE FLORIDA PENINSULA AND INTO THE W ATLC DIPPING S INTO THE NW CARIBBEAN. THE GULF REMAINS RATHER QUIET THIS EVENING WITH SOME ISOLATED SHOWERS ALONG THE W COAST OF FLORIDA DUE TO THE EASTERLY FLOW FROM THE W ATLC. THE SURFACE RIDGE WILL SHIFT EASTWARD THROUGH SUN AHEAD OF THE NEXT FRONT IS EXPECTED TO ENTER THE GULF LATE IN THE WEEKEND. CARIBBEAN SEA... THE UPPER TROUGH OVER FLORIDA AND THE W ATLC EXTENDS INTO THE NW CARIBBEAN N OF 16N W OF OF THE WINDWARD PASSAGE THE YUCATAN PENINSULA. THE REMAINDER OF THE CARIBBEAN IS DOMINATED BY AN UPPER RIDGE THAT EXTENDS FROM AN UPPER HIGH OFF THE COAST OF SOUTH AMERICA SE OF TRINIDAD. THIS ADVECTING TROPICAL MOISTURE OVER THE SE CARIBBEAN WITH SCATTERED SHOWERS AND POSSIBLE ISOLATED THUNDERSTORMS S OF 14N BETWEEN 74W TO ACROSS THE WINDWARD ISLANDS. MODERATE EASTERLY TRADE WINDS COVER THE AREA RESULTING FROM THE WEAK PRESSURE GRADIENT OVER THE ATLC WATERS. AFTERNOON SHOWERS/ISOLATED THUNDERSTORMS HAVE GENERATED OVER PORTIONS OF HISPANIOLA AND JAMAICA NOW DRIFTING NE MOSTLY INTO THE W ATLC COASTAL WATERS. STRONG SUBSIDENCE AND DRY AIR THAT DOMINATES THE REMAINDER OF THE CARIBBEAN RESULTING IN CLEAR SKIES MAINLY OVER THE NW CARIBBEAN. ATLANTIC OCEAN... BROAD UPPER TROUGH THAT COVERS THE E GULF OF MEXICO EXTENDS OVER THE W ATLC W OF 60W WITH A WEAK UPPER LOW NEAR 29N66W. A WEAKENING 1012 MB LOW MOVING S IS CENTERED NEAR 27N71W WITH NO SHOWER ACTIVITY. A SECOND SURFACE 1011 MB LOW IS TO THE E NEAR 28N67W WITH A SURFACE TROUGH EXTENDING ALONG 26N65W TO NEAR 22N70W. CLUSTERS OF SCATTERED SHOWERS/THUNDERSTORMS ARE E OF THE SURFACE TROUGH FROM 20N-31N BETWEEN 50W-66W. AFTERNOON SHOWERS/ISOLATED THUNDERSTORMS HAVE GENERATED INLAND OVER PORTIONS OF HISPANIOLA AND ARE DRIFTING NE OVER THE IMMEDIATE COASTAL WATERS. A STRONG UPPER LOW IS OVER THE N/CENTRAL ATLC WITH AN ASSOCIATED COLD FRONT APPROACHING THE REGION AND A SURFACE TROUGH EXTENDING INTO THE REGION NEAR 32N37W ALONG 24N46W TO 26N51W. AN UPPER RIDGE EXTENDS FROM AN UPPER HIGH OFF THE SOUTH AMERICA COAST NEAR 9N54W NE TO BEYOND 32N45W AND COVERS THE REMAINDER OF THE ATLC. $$ WALLACE