000 AXNT20 KNHC 150544 TWDAT TROPICAL WEATHER DISCUSSION NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL 205 AM EDT SAT MAY 15 2010 TROPICAL WEATHER DISCUSSION FOR NORTH AMERICA...CENTRAL AMERICA...GULF OF MEXICO...CARIBBEAN SEA...NORTHERN SECTIONS OF SOUTH AMERICA...AND 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 0515 UTC... ...TROPICAL WAVES... TROPICAL WAVE IS ALONG 17W/18W S OF 8N MOVING W 10-15 KT. WAVE IS EMBEDDED WITHIN A SLIGHT MOISTURE MAXIMUM ON THE TOTAL PRECIPITABLE WATER IMAGERY. THIS WAVE PASSED THROUGH NIAMEY NIGER IN W AFRICA LATE ON THE 12TH AS INDICATED BY UPPER AIR SOUNDING. NO ASSOCIATED DEEP CONVECTION. TROPICAL WAVE IS ALONG 44W/45W S OF 9N MOVING W NEAR 20 KT. WAVE IS EMBEDDED WITHIN A MOISTURE MAXIMUM ON THE TOTAL PRECIPITABLE WATER IMAGERY. SCATTERED MODERATE/STRONG CONVECTION IS FROM 5N-8N BETWEEN 44W-47W WITH CLUSTERS OF SCATTERED MODERATE/ ISOLATED STRONG CONVECTION FROM 2N-5N BETWEEN 43W-46W. TROPICAL WAVE IS ALONG 51W S OF 9N MOVING W NEAR 15 KT. WAVE IS EMBEDDED WITHIN A SECOND MOISTURE MAXIMUM ON THE TOTAL PRECIPITABLE WATER IMAGERY. CLUSTERS OF SCATTERED MODERATE/ STRONG CONVECTION ARE FROM 5N-10N BETWEEN 46W-56W. ...THE ITCZ... THE ITCZ AXIS IS ANALYZED ALONG 10N13W 1N32W 1N53W. SCATTERED MODERATE/ISOLATED STRONG CONVECTION IS WITHIN 60 NM OF LINE FROM 4N23W 2N35W TO 5N40W AND FROM 1N-4N E OF 11W ACROSS THE PRIME MERIDIAN. CLUSTERS OF SCATTERED MODERATE CONVECTION ARE FROM THE EQUATOR TO 2N BETWEEN 37W-43W. ...DISCUSSION... GULF OF MEXICO... AN UPPER RIDGE COVERS S MEXICO ANCHORED IN THE E PACIFIC REGION EXTENDING OVER THE BAY OF CAMPECHE AND THE YUCATAN PENINSULA GENERATING CLUSTERS OF SCATTERED SHOWERS/ISOLATED THUNDERSTORMS INLAND OVER MEXICO AND IN THE GULF WATERS S OF 25N W OF 93W. A SHORTWAVE UPPER TROUGH IS OVER TEXAS/MEXICO BORDER FROM DEL RIO TEXAS TO BROWNSVILLE COVERING THE NW GULF N OF 27N W OF 92W GENERATING CLUSTERS OF SCATTERED/HEAVY SHOWERS WITH SCATTERED THUNDERSTORMS INLAND OVER TEXAS AND WITHIN 90 NM ALONG THE COAST OF TEXAS FROM S OF CORPUS CHRISTI TO LAKE CHARLES LOUISIANA. THE REMAINDER OF THE GULF CONTINUES TO BE DOMINATED BY A SECOND UPPER LEVEL RIDGE THAT EXTENDS FROM W CUBA ACROSS THE FLORIDA PENINSULA INTO THE FAR W ATLC. BROKEN TO OVERCAST HIGH CLOUDS COVER MOST OF THE GULF AGAIN TONIGHT WITH SOME FAST MOVING ISOLATED SHOWERS IN THE FLORIDA STRAITS S OF 25N TO OVER W CUBA E OF 85W INCLUDING THE FLORIDA KEYS. THE SURFACE RIDGE ANCHORED IN THE W ATLC CONTINUES TO COVER THE E GULF MAINTAINING MODERATE TO FRESH EASTERLY WINDS ACROSS MUCH THE GULF WITH THE STRONGEST WINDS IN THE FLORIDA STRAITS. THIS SURFACE RIDGE IS EXPECTED TO WEAKEN AND SHIFT E DIMINISHING THE WINDS LATE IN THE WEEKEND. CARIBBEAN SEA... THE UPPER RIDGE OVER THE S GULF OF MEXICO COVERS THE FAR NW CARIBBEAN W OF 85W WHILE A SECOND UPPER RIDGE ANCHORED IN THE TROPICAL ATLC COVERS THE E CARIBBEAN AND AN UPPER TROUGH IS BETWEEN THAT EXTENDS ACROSS E CUBA TO S NICARAGUA/COSTA RICA. STRONG SUBSIDENCE AND DRY STABLE AIR COVERS THE CENTRAL CARIBBEAN LEAVING THE AREA RATHER W OF A LINE FROM MONA PASSAGE TO COSTA RICA CLEAR AGAIN TONIGHT. THE SURFACE RIDGE OVER THE W ATLC IS MAINTAINING MODERATE TO STRONG EASTERLY TRADE WINDS ACROSS THE AREA. THIS SURFACE RIDGE IS EXPECTED TO WEAKEN AND SHIFT E DIMINISHING THE WINDS LATE IN THE WEEKEND. THE UPPER LEVEL FLOW OVER THE SE CARIBBEAN IS GIVING THE AREA S OF THE LINE FROM THE MONA PASSAGE TO COSTA RICA BROKEN/OVERCAST MULTILAYERED CLOUDS WITH ISOLATED SHOWERS INCLUDING THE LESSER ANTILLES. CONVERGENCE OF UPPER LEVEL FLOW AND THE SURFACE FLOW OVER THE SW CARIBBEAN IS GENERATING SCATTERED SHOWERS/ISOLATED THUNDERSTORMS S OF 11N TO INLAND OVER PANAMA W OF 80W TO THE COAST OF COSTA RICA. ATLANTIC OCEAN... A WEAKENING BROAD SURFACE RIDGE DOMINATES THE W ATLC ANCHORED BY A 1027 MB HIGH NEAR 32N69W. AN UPPER TROUGH IS OVER THE SW ATLC EXTENDING FROM 26N68W ACROSS THE BAHAMAS AND E CUBA INTO THE CENTRAL CARIBBEAN GENERATING SCATTERED SHOWERS/ISOLATED THUNDERSTORMS FROM 21N-23N BETWEEN 69W-73W INCLUDING THE TURKS AND CAICOS. THIS IS LEAVING THE REMAINDER OF THE W ATLC UNDER DRY STABLE AIR AND THUS CLEAR SKIES AGAIN TONIGHT. AN UPPER TROUGH IS OVER THE CENTRAL ATLC N OF 25N BETWEEN 32W-55W SUPPORTING A COLD FRONT THAT ENTERS THE REGION NEAR 32N45W EXTENDING TO 29N52W BECOMING STATIONARY ALONG 28N56W 30N62W TO A VERY WEAK 1024 MB LOW NEAR 30N66W. ISOLATED SHOWERS ARE POSSIBLE WITHIN 60 NM EITHER SIDE OF THE COLD FRONT. A SERIES OF VERY WEAK SURFACE TROUGHS ARE IN THE CENTRAL ATLC FROM 17N-28N BETWEEN 40W-60W WITH NO ASSOCIATED SHOWER ACTIVITY. A BROAD UPPER RIDGE CONTINUES TO COVER THE TROPICAL ATLC S OF 21N E OF 70W TO OVER SW AFRICA. A SURFACE RIDGE DOMINATES THE E ATLC ANCHORED BY A 1032 MB HIGH JUST N OF THE AZORES. FOR ADDITIONAL INFORMATION PLEASE VISIT HTTP://WWW.HURRICANES.GOV/MARINE $$ WALLACE