000 AXNT20 KNHC 190547 TWDAT TROPICAL WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 205 AM EDT TUE JUN 18 2012 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 0000 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 0515 UTC. ...SPECIAL FEATURES... A NON-TROPICAL LOW IS LOCATED ABOUT 475 NM NE OF BERMUDA. SHOWER/THUNDERSTORM ACTIVITY HAS DECREASED THIS EVENING. THE CHANCES FOR DEVELOPMENT OF THIS SYSTEM ARE DECREASING AS THE LOW IS FORECAST TO ENCOUNTER COOLER WATERS AND A MORE STABLE ATMOSPHERE WITHIN A DAY OR SO. THIS SYSTEM HAS A MEDIUM CHANCE OF BECOMING A TROPICAL OR SUBTROPICAL CYCLONE DURING THE NEXT 48 HOURS AS IT MOVES EAST-NORTHEASTWARD AT 9 TO 13 KT. FOR ADDITIONAL INFORMATION ON THIS SYSTEM...PLEASE SEE HIGH SEAS FORECASTS ISSUED BY THE OCEAN PREDICTION CENTER. ...TROPICAL WAVES... TROPICAL WAVE IS ALONG 44W/45W S OF 12N MOVING W NEAR 15-20 KT. WAVE IS LOW AMPLITUDE AND IS ALONG THE WESTERN EDGE OF AN UPPER RIDGE. NO ASSOCIATED CONVECTION. TROPICAL WAVE IS ALONG 58W S OF 15N MOVING W 15-20 KT. THIS IS WAVE IS APPROACHING THE LESSER ANTILLES BUT IS EMBEDDED WITHIN AN AREA OF RELATIVELY DRY AIR. THUS...NO ASSOCIATED CONVECTION. ...ITCZ/MONSOON TROUGH... THE MONSOON TROUGH EXTENDS ACROSS W AFRICA INTO THE E TROPICAL ATLC NEAR 16N16W CONTINUING ALONG 11N21W TO 8N26W WHERE THE ITCZ CONTINUES ALONG 6N36W TO 7N43W THEN RESUMES W OF THE TROPICAL WAVE NEAR 6N47W TO INLAND OVER SOUTH AMERICA NEAR 6N55W. CLUSTERS OF SCATTERED MODERATE/ISOLATED STRONG CONVECTION ARE FROM THE ITCZ TO 11N BETWEEN 48W-54W. SMALL SCATTERED CLUSTERS OF SCATTERED MODERATE CONVECTION ARE WITHIN 60/75 NM OF LINE FROM 6N12W 7N20W 5N36W. ...DISCUSSION... GULF OF MEXICO... THE GULF IS DOMINATED BY A PAIR OF UPPER LOWS. ONE IS CENTERED INLAND OVER NE MEXICO NEAR 36N99W COVERING THE THE W GULF AND THE SECOND COVERING THE E GULF CENTERED NEAR 25N87W.THE UPPER RIDGE OVER THE W CARIBBEAN EXTENDS N OVER THE STRAITS OF FLORIDA WITH SCATTERED SHOWERS AND POSSIBLE ISOLATED THUNDERSTORMS S OF THE FLORIDA KEYS E OF 85W. SOME ISOLATED SHOWERS/THUNDERSTORMS ARE POSSIBLE WITHIN 90 NM OFF THE W COAST OF FLORIDA...OVER THE NW GULF N OF 26N BETWEEN 90W-96W...AND IN THE BAY OF CAMPECHE S OF 20N E OF 93W. OTHERWISE THE GULF REMAINS FAIRLY QUIET TONIGHT WITH MOSTLY CLEAR CLEAR SKIES. WEAK SURFACE RIDGE EXTENDS FROM THE W ATLC OVER THE E GULF ANCHORED BY A 1019 MB HIGH OVER NORTH CAROLINA. HIGH PRESSURE WILL CONTINUE TO BUILD OVER THE E GULF TONIGHT. WEAK LOW AND ACCOMPANYING SURFACE TROUGH WILL MOVE INTO THE GULF FROM THE YUCATAN CHANNEL AND PENINSULA WED THEN DRIFTING NW THROUGH SAT. CARIBBEAN SEA... BROAD UPPER RIDGE COVERS THE CARIBBEAN ANCHORED NEAR HAITI EXTENDING AN AXIS WNW ACROSS CUBA TO THE STRAITS OF FLORIDA AND E TO THE LEEWARD ISLANDS. THIS IS PROVIDING DIFFLUENCE ALOFT TO GENERATE SCATTERED TO HEAVY SHOWERS WITH ISOLATED THUNDERSTORMS N OF A LINE FROM THE HAITI/DOMINICAN REPUBLIC BORDER TO 15N82W TO OVER CUBA AND HAITI. THE 1009 MB LOW HAS MOVED INLAND OVER HONDURAS AND AT 19/0300 UTC IS CENTERED NEAR 15N85W WITH A SURFACE TROUGH EXTENDING INTO THE CARIBBEAN WATERS ALONG 18N83W TO 21N80W WITH ISOLATED SHOWERS AND POSSIBLE ISOLATED THUNDERSTORMS OVER THE W CARIBBEAN W OF 83W. THIS IS LEAVING THE S AND E CARIBBEAN INCLUDING THE LESSER ANTILLES UNDER MOSTLY CLEAR SKIES TONIGHT. LOW/SURFACE TROUGH WILL DRIFT NW REACHING THE YUCATAN CHANNEL AND PENINSULA TUE NIGHT. A TROPICAL WAVE IN THE TROPICAL WILL REACH THE E CARIBBEAN TUE NIGHT THEN INTO THE CENTRAL CARIBBEAN WED NIGHT BEFORE BECOMING DIFFUSE OVER THE SW CARIBBEAN THU. A SECOND TROPICAL WAVE WILL ENTER INTO THE E CARIBBEAN LATE FRI. ATLANTIC OCEAN... THE BROAD UPPER TROUGH OVER THE W ATLC IS BEGINNING TO WEAKEN AS THE UPPER LOW/SURFACE LOW MOVES PULLS FURTHER AWAY FROM THE DISCUSSION AREA. THE UPPER TROUGH EXTENDS ACROSS BERMUDA TO 27N67W CONTINUING TO SUPPORT THE 1006 MB LOW IN SPECIAL FEATURES ABOVE AND A SURFACE TROUGH ENTERING THE W/CENTRAL ATLC NEAR 32N59W EXTENDING ALONG 26N66W TO 23N73W. SCATTERED TO HEAVY SHOWERS AND SCATTERED THUNDERSTORMS ARE FROM 21N-25N BETWEEN 66W-72W WITH SCATTERED SHOWERS/ISOLATED THUNDERSTORMS FROM THE BAHAMAS TO THE GREATER ANTILLES W OF 71W THROUGH THE STRAITS OF FLORIDA. THE UPPER RIDGE OVER THE CARIBBEAN EXTENDS AN UPPER RIDGE AXIS FROM THE VIRGIN/LEEWARD ISLANDS NE ALONG 25N58W TO BEYOND 32N49W PROVIDING DIFFLUENCE ALOFT TO GENERATE SCATTERED SHOWERS WITH POSSIBLE ISOLATED THUNDERSTORMS WITHIN 300 NM SE OF THE REMAINDER OF THE ABOVE SURFACE TROUGH. A BROAD SURFACE RIDGE DOMINATES THE REMAINDER OF THE ATLC E OF 60W ANCHORED BY A 1027 MB HIGH NEAR 31N34W. SURFACE TROUGH WILL REMAIN NEARLY STATIONARY OVERNIGHT THEN WILL DRIFT W TUE APPROACHING FLORIDA WED AND THU. SURFACE RIDGE WILL BUILD IN FROM THE E BEHIND THE TROUGH WED THROUGH SAT. FOR ADDITIONAL INFORMATION PLEASE VISIT HTTP://WWW.HURRICANES.GOV/MARINE $$ PAW