000 AXNT20 KNHC 310004 TWDAT TROPICAL WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 805 PM EDT THU MAY 30 2013 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...WEATHER OBSERVATIONS...RADAR...AND METEOROLOGICAL ANALYSIS. BASED ON 1800 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 2315 UTC. ...ITCZ/MONSOON TROUGH... THE MONSOON TROUGH EXTENDS ACROSS AFRICA INTO THE E TROPICAL ATLC NEAR 14N17W CONTINUING ALONG 9N21W TO 7N24W WHERE THE ITCZ BEGINS AND CONTINUES ALONG 6N34W 5N43W 3N49W TO INLAND OVER SOUTH AMERICA NEAR 4N51W. CLUSTERS OF SCATTERED MODERATE/ ISOLATED STRONG CONVECTION ARE FROM 3N-7N BETWEEN 2W-20W INCLUDING PORTIONS OF SW AFRICA AND S OF 10N W OF 51W TO INLAND OVER SOUTH AMERICA. SMALL CLUSTERS OF SCATTERED MODERATE CONVECTION ARE FROM 4N-9N BETWEEN 32W-37W AND WITHIN 60 NM OF LINE FROM 5N46W TO 6N51W. ...DISCUSSION... GULF OF MEXICO... AN UPPER TROUGH IS SWEEPING E ACROSS THE W GULF WITH THE AXIS EXTENDING ACROSS MOBILE ALABAMA TO INLAND OVER MEXICO NEAR TAMPICO. DRY STABLE AIR WITH STRONG SUBSIDENCE COVERS THE W GULF W OF THE UPPER TROUGH AXIS. AN UPPER RIDGE COVERS THE REMAINDER OF THE GULF WITH THE RIDGE AXIS EXTENDING FROM THE YUCATAN PENINSULA NEAR MERIDA TO OVER NE FLORIDA NEAR 30N83W CONTINUING N OVER THE E CONUS. A STRONG SURFACE RIDGE EXTENDS FROM THE W ATLC OVER THE SE CONUS GIVING THE GULF SE SURFACE FLOW. THE REMNANTS OF TROPICAL CYCLONE BARBARA THAT CROSSED S MEXICO OVER THE PAST 24 HOURS IS IS MOVING INTO THE BAY OF CAMPECHE AND AT 30/2100 UTC WAS LOCATED AT 18.5N94.5W. HOWEVER...VISIBLE SATELLITE IMAGERY INDICATES THAT THE LOW IS BECOMING SLIGHTLY ELONGATED INTO THE GULF WATERS. SCATTERED SHOWERS ARE S OF 20N BETWEEN 93W-95W. A SURFACE TROUGH IS ALONG THE W COAST OF THE YUCATAN PENINSULA EXTENDING FROM 23N89W TO 18N91W WITH SCATTERED SHOWERS/THUNDERSTORMS WITHIN 90 NM E OF THE TROUGH AXIS S OF 22N. A SECOND WEAKER SURFACE TROUGH IS IN THE NE GULF EXTENDING FROM THE BIG BEND REGION NEAR 30N84W ALONG THE W COAST OF FLORIDA TO FLORIDA BAY NEAR 25N82W WITH SCATTERED SHOWERS/ ISOLATED THUNDERSTORMS WITHIN 45 NM EITHER SIDE OF THE TROUGH AXIS. THIS IS LEAVING THE REMAINDER OF THE GULF WITH MOSTLY CLEAR SKIES THIS EVENING. W ATLC SURFACE RIDGE WILL PERSIST THROUGH SAT. A LOW LEVEL TROUGH POSSIBLY ATTRIBUTED TO THE REMNANTS OF BARBARA WILL DEVELOP OVER THE SW GULF OVER THE WEEKEND AND MEANDER E TOWARDS THE YUCATAN PENINSULA MON AND TUE. CARIBBEAN SEA... THE UPPER RIDGE IN THE E GULF OF MEXICO COVERS THE W CARIBBEAN W OF 80W WITH BENIGN UPPER LEVEL FEATURES COVER THE REMAINDER OF THE CARIBBEAN BASIN. THE UPPER RIDGE IS PROVIDING DIFFLUNCE ALOFT TO GENERATE SCATTERED SHOWERS/ISOLATED THUNDERSTORMS OVER THE W CARIBBEAN FROM CENTRAL AMERICA TO CUBA BETWEEN 77W-85W INCLUDING AND JAMAICA. EASTERLY TRADE WINDS ARE USHERING IN SOME SCATTERED LOW LEVEL SHOWERS OVER THE REMAINDER OF THE CARIBBEAN E OF 77W. W ATLC SURFACE RIDGE WILL MAINTAIN MODERATE TO FRESH TRADE WINDS ACROSS MUCH OF THE BASIN THROUGH TUE. HISPANIOLA... CURRENTLY SCATTERED SHOWERS/ISOLATED THUNDERSTORMS DOT THE ENTIRE ISLAND WITH THE HEAVIEST RAINFALL TOTALS OVER THE MOUNTAINOUS REGION OF THE DOMINICAN REPUBLIC. THESE SHOWERS/ THUNDERSTORMS ARE LESS INTENSE COMPARED TO THE PAST FEW DAYS. ATLANTIC OCEAN... THE UPPER TROUGH EXTENDS FROM AN UPPER LOW OFF THE NORTH CAROLINA COAST THROUGH 32N75W TO THE N COAST OF CUBA NEAR 22N77W. THIS UPPER TROUGH IS AMPLIFYING AN UPPER RIDGE THAT EXTENDS FROM HISPANIOLA TO BEYOND 32N65W. THIS UPPER RIDGE IS PROVIDING DIFFLUNCE ALOFT TO GENERATE SCATTERED SHOWERS N OF 23N BETWEEN 70W-75W WITH SCATTERED SHOWERS/ISOLATED THUNDERSTORMS WITHIN 90 NM OF LINE FROM 21N70W 23N77W TO OVER FLORIDA NEAR 25N80W. BENIGN UPPER LEVEL FEATURES COVER THE REMAINDER OF THE ATLC BASIN. A PAIR OF WEAK SURFACE TROUGHS ARE IN THE CENTRAL ATLC EXTENDING FROM 32N52W TO 27N56W AND FROM 31N45W TO 26N47W. A BROAD SURFACE RIDGE COVERS THE ENTIRE ATLC WITH A WEAKNESS IN THE VICINITY OF THE ABOVE SURFACE TROUGHS ANCHORED BY SURFACE HIGHS WELL N OF THE DISCUSSION AREA. W ATLC SURFACE RIDGE WILL PERSIST THROUGH MON. A LOW LEVEL TROUGH DRIFTING ACROSS FLORIDA WILL REMAIN NEARLY STATIONARY BETWEEN FLORIDA AND THE BAHAMAS THROUGH SAT THEN DISSIPATE SUN. A WEAK TROUGH IS EXPECTED TO DEVELOP E OF THE BAHAMAS SUN AND MON. FOR ADDITIONAL INFORMATION PLEASE VISIT HTTP://WWW.HURRICANES.GOV/MARINE $$ PAW