000 AXNT20 KNHC 280517 TWDAT TROPICAL WEATHER DISCUSSION NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL 205 AM EDT WED MAY 28 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 WAS INTRODUCED ALONG 20W/21W S OF 14N MOVING W NEAR 10 KT BASED ON SATELLITE IMAGERY AND MODEL MOISTURE FIELDS. CLUSTERS OF SCATTERED MODERATE/STRONG CONVECTION ARE WITHIN 150 NM OF THE WAVE AXIS FROM 2N-9N. TROPICAL WAVE IS ANALYZED ALONG ALONG 36W S OF 9N MOVING W NEAR 15 KT BASED ON SATELLITE IMAGERY AND MODEL MOISTURE FIELDS. ANY CONVECTION IS ASSOCIATED WITH THE ITCZ. TROPICAL WAVE IS FROM 8N58W TO 21N61W MOVING W NEAR 15 KT. WELL DEFINED HIGH AMPLITUDE WAVE IS BETWEEN BARBADOS AND THE REMAINDER OF THE LESSER ANTILLES. THE N PORTION OF THIS WAVE IS NOW A SEPARATE FEATURE. THE UPPER LEVEL FEATURES CONTINUE TO ENHANCE THIS TROPICAL WAVE. SCATTERED SHOWERS/ISOLATED THUNDERSTORMS ARE WITHIN 120 NM E OF THE WAVE AXIS. TROPICAL WAVE IS ANALYZED ALONG 77W S OF 19N MOVING W NEAR 15 KT. WAVE IS EMBEDDED WITHIN A BROAD AREA OF LOWER PRESSURE AND AN AREA OF CONVECTION ASSOCIATED WITH THE ITCZ. ...ITCZ... ITCZ AXIS IS CENTERED ALONG 8N12W 7N22W 3N31W 2N43W EQ49W AND ACROSS THE SW CARIBBEAN ALONG 11N74W ACROSS COSTA RICA/NICARAGUA INTO THE E PACIFIC REGION. CLUSTERS OF SCATTERED/NUMEROUS STRONG CONVECTION ARE FROM 2N TO THE SW COAST OF AFRICA E OF 6W ACROSS THE PRIME MERIDIAN. CLUSTERS OF SCATTERED MODERATE/STRONG CONVECTION ARE FROM THE EQUATOR TO 6N BETWEEN 6W-18W. CLUSTERS OF SCATTERED MODERATE/ISOLATED STRONG CONVECTION ARE FROM 1N-7N BETWEEN 22W-31W. ...DISCUSSION... GULF OF MEXICO... UPPER LEVEL RIDGE COVERS THE GULF W OF 90W ANCHORED OVER SW MEXICO. A SMALL UPPER LOW IS CENTERED NEAR 29N87W WITH A NARROW UPPER TROUGH COVERING THE CENTRAL GULF EXTENDING S TO THE YUCATAN PENINSULA. A SECOND UPPER RIDGE EXTENDS FROM THE W ATLC OVER THE E GULF E OF 84W. THESE ARE RELATIVELY BENIGN FEATURES AS THE ENTIRE GULF IS DOMINATED BY MODERATE/STRONG SUBSIDENCE AND DRY UPPER AIR. WEAK SURFACE RIDGE EXTENDS INTO THE NE GULF FROM THE W ATLC WITH MODERATE EASTERLY SURFACE WINDS. THE ONLY AREA OF CONCERN IS THE SE GULF WHERE THERE ARE SCATTERED SHOWERS/ISOLATED THUNDERSTORMS S OF 26N E OF 85W TO THE FLORIDA COAST...OVER THE FLORIDA KEYS AND THROUGH THE FLORIDA STRAITS DUE TO THE FRONT IN THE W ATLC THAT IS RETREATING AS A WARM FRONT TO OVER CUBA. OTHERWISE THE REMAINDER OF THE GULF IS RATHER CLEAR AGAIN TONIGHT. CARIBBEAN SEA... BROAD UPPER RIDGE DOMINATES MUCH OF THE CARIBBEAN WITH AN INDUCED UPPER TROUGH OVER THE NW CARIBBEAN BETWEEN THIS UPPER RIDGE AND THE UPPER RIDGE OVER THE W GULF OF MEXICO THAT EXTENDS FROM W CUBA TO OVER CENTRAL AMERICA IN THE GULF OF HONDURAS. THE REMNANTS OF A FRONTAL BOUNDARY OVER CUBA ARE GENERATING SCATTERED SHOWERS/THUNDERSTORMS N OF 19N FROM THE WINDWARD PASSAGE TO 84W. THE SW UPPER FLOW ACROSS THE S CARIBBEAN IS DRAWING UPPER LEVEL MOISTURE ACROSS CENTRAL AMERICA INTO THE CARIBBEAN AND COUPLED WITH THE ITCZ AXIS IN THE SW CARIBBEAN AS WELL AS AN ILL DEFINED 1006 MB SURFACE LOW EMBEDDED WITHIN THE ITCZ NEAR 11N82W IS PRODUCING A BROAD AREA OF DENSE CLOUDINESS WITH SCATTERED SHOWERS/ISOLATED THUNDERSTORMS S OF 14N FROM OVER COLOMBIA TO OVER CENTRAL AMERICA. A TROPICAL WAVE IS MOVING OVER THE LESSER ANTILLES GIVING THE ISLANDS SCATTERED SHOWERS AND POSSIBLE ISOLATED THUNDERSTORMS OVER THE NEXT SEVERAL HOURS. ATLANTIC... AN UPPER RIDGE IS OVER THE FAR W ATLC INTO THE E GULF OF MEXICO WITH A WELL DEFINED UPPER LOW NEAR 31N66W EXTENDING A SHEAR AXIS S OF THE UPPER RIDGE ALONG 25N70W TO OVER CUBA NEAR 22N78W. A REMNANT FRONTAL BOUNDARY IS BEGINNING TO LIFT BACK N SLOWLY AS A WARM FRONT THAT EXTENDS THROUGH 32N64W TO THE BAHAMAS NEAR 23N75W DISSIPATING TO OVER CUBA NEAR 21N78W. CLUSTERS OF SCATTERED SHOWERS/ISOLATED THUNDERSTORMS ARE S OF 23N BETWEEN 70W AND THE FLORIDA STRAITS INCLUDING THE TURKS AND CAICOS. SIMILAR ACTIVITY IS ASSOCIATED WITH THE UPPER LOW WITHIN 90 NM OF THE FRONT N OF 27N. AN UPPER RIDGE EXTENDS FROM THE BROADER UPPER RIDGE OVER THE CARIBBEAN ACROSS THE VIRGIN/LEEWARD ISLANDS NE TO BEYOND 32N50W. THE N PORTION OF THE TROPICAL WAVE APPROACHING THE LESSER ANTILLES HAS BROKEN OFF AS A SURFACE TROUGH EXTENDING FROM 23N61W TO 28N57W WITH SCATTERED SHOWERS/ THUNDERSTORMS COVERING THE AREA FROM 23N-28N BETWEEN 57W-62W. BROAD UPPER TROUGH IS IN THE E/CENTRAL ATLC EXTENDING FROM AN ELONGATED UPPER LOW NEAR 32N34W SW INTO THE TROPICAL ATLC TO NEAR 13N48W WITH A SECOND UPPER TROUGH OVER THE FAR E ATLC E OF 20W OVER THE CANARY ISLANDS AND WESTERN SAHARA AFRICA. THE E AND CENTRAL ATLC IS DOMINATED BY A SURFACE RIDGE N OF 15N BRIDGING THE FRONT IN THE W ATLC ACROSS THE NE GULF OF MEXICO ANCHORED BY A 1028 MB HIGH NEAR 33N45W. THE RESULT IS CALM WEATHER FOR THE ATLC E OF 55W. $$ WALLACE