000 AXNT20 KNHC 281049 TWDAT TROPICAL WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 805 AM EDT SAT APR 28 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 0600 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 1015 UTC. ...ITCZ/MONSOON TROUGH... THE MONSOON TROUGH EXTENDS ACROSS W AFRICA ENTERING THE E TROPICAL ATLC NEAR 8N16W TO 6N15W WHERE THE ITCZ AXIS CONTINUES ALONG 4N21W 3N27W 3N35W THEN S OF THE EQUATOR NEAR 48W. CLUSTERS OF SCATTERED MODERATE/ISOLATED STRONG CONVECTION ARE FROM 1N-6N BETWEEN 2W-42W. ...DISCUSSION... GULF OF MEXICO... A VERY NARROW UPPER TROUGH EXTENDS FROM NE FLORIDA S ACROSS THE E GULF INTO THE CARIBBEAN THROUGH THE YUCATAN CHANNEL. A SURFACE TROUGH IS ALONG THE E SIDE OF THE UPPER TROUGH EXTENDING AT 28/0900 UTC ACROSS S FLORIDA INTO THE FAR SE GULF NEAR 25N81W ACROSS THE LOWER FLORIDA KEYS THEN TO ACROSS CUBA INTO THE NW CARIBBEAN NEAR 23N89W. SCATTERED TO HEAVY SHOWERS/ISOLATED THUNDERSTORMS ARE E OF THE SURFACE TROUGH OUT OF THE GULF AND WITHIN 60 NM W OF THE TROUGH. A BROAD UPPER RIDGE DOMINATES THE REMAINDER OF THE GULF WITH A RIDGE AXIS EXTENDING FROM THE E PACIFIC REGION ACROSS MEXICO NEAR TUXPAN TO THE N GULF COAST NEAR PENSACOLA FLORIDA. A SURFACE RIDGE EXTENDS FROM W ATLC ACROSS FLORIDA TO OVER THE GULF TO 91W WITH A 1019 MB HIGH OFF THE FLORIDA COAST JUST NEAR TAMPA. THIS SURFACE RIDGE CONTINUES TO PRODUCE SOUTHERLY RETURN FLOW ACROSS MOST OF THE N GULF N OF 26N W OF 86W. MODERATE/STRONG SUBSIDENCE AND DRY STABLE AIR COVERS MOST OF THE GULF GIVING WAY TO THE SURFACE TROUGH OVER THE FAR SE GULF BUT LEAVING THE REMAINDER OF THE GULF UNDER CLEAR SKIES AGAIN THIS MORNING. THE SURFACE RIDGE EXTENDING FROM THE W ATLC WILL SHIFT N ACROSS THE N GULF COAST TONIGHT THEN SHIFT N OF AREA ON SUN. THE SURFACE TROUGH WILL MOVE NW INTO THE E GULF THROUGH TONIGHT BEFORE DISSIPATING. A SECOND BROADER SURFACE TROUGH WILL MOVE W THROUGH THE STRAITS OF FLORIDA SUN CONTINUE W TO THE S CENTRAL GULF ON TUE BEFORE WEAKENING OVER THE W GULF ON WED. CARIBBEAN SEA... THE VERY NARROW UPPER TROUGH EXTENDS OVER THE FAR W CARIBBEAN FROM THE E GULF OF MEXICO THROUGH THE YUCATAN CHANNEL TO OVER HONDURAS. A SURFACE TROUGH IS ALONG THE E SIDE OF THE UPPER TROUGH EXTENDING AT 28/0900 UTC FROM 20N84W ACROSS CUBA NEAR 23N89W INTO THE GULF OF MEXICO. SCATTERED TO HEAVY SHOWERS/ ISOLATED THUNDERSTORMS ARE N OF 18N E OF THE SURFACE TROUGH TO 79W AND WITHIN 60 NM W OF THE TROUGH. SCATTERED SHOWERS ARE N OF 16N BETWEEN 73W-79W. A BROAD UPPER RIDGE DOMINATES THE REMAINDER OF THE CARIBBEAN BASIN E OF 82W ANCHORED JUST W OF THE WINDWARD ISLANDS. A WEAK SURFACE TROUGH IS BENEATH THIS UPPER RIDGE EXTENDING FROM 16N78W TO 12N80W AND IS EMBEDDED WITHIN DENSE CLOUD COVER WITH SCATTERED SHOWERS AND POSSIBLE ISOLATED SHOWERS WITHIN 250 NM W OF THE TROUGH. FRESH EASTERLY TRADE WINDS COVER THE E INTO THE CENTRAL CARIBBEAN THROUGH MON THEN WILL DIMINISH SLIGHTLY TUE AND WED. ATLANTIC OCEAN... THE BROAD UPPER RIDGE OVER THE CARIBBEAN EXTENDS TO OVER THE W AND CENTRAL ATLC S OF 32N W OF 47W. A SURFACE TROUGH IS ALONG THE W SIDE OF THE UPPER RIDGE EXTENDING AT 28/0900 UTC ACROSS S FLORIDA FROM JUST OFFSHORE NEAR WEST PALM BEACH INTO THE FAR SE GULF THEN INTO THE NW CARIBBEAN. SCATTERED TO HEAVY SHOWERS/ ISOLATED THUNDERSTORMS ARE WITHIN 250 NM W AND WITHIN 60 NM E OF THE SURFACE TROUGH. SCATTERED SHOWERS ARE S OF 26N BETWEEN 70W-77W. A SURFACE RIDGE EXTENDS FROM THE CENTRAL ATLC ALONG 30N TO 70W THEN ACROSS CENTRAL FLORIDA INTO THE GULF OF MEXICO WITH A WEAKNESS IN THE IMMEDIATE VICINITY OF A SURFACE TROUGH THAT EXTENDS FROM 28N64W TO 24N70W. AN UPPER TROUGH OVER THE E ATLC EXTENDS S TO 10N E OF 46W SUPPORTING A DISSIPATING COLD FRONT THAT ENTERS THE REGION OFF WESTERN SAHARA AFRICA NEAR 26N14W S OF THE CANARY ISLANDS TO 24N19W WITH A SURFACE TROUGH FURTHER SW EXTENDING FROM 19N40W TO 12N47W. ANY SHOWER ACTIVITY IS INLAND OVER AFRICA. THE SURFACE TROUGH MOVING ACROSS S FLORIDA WILL EXIT THE STRAITS OF FLORIDA THIS MORNING. THE SURFACE RIDGE EXTENDING ACROSS THE W ATLC WILL SHIFT N TO ALONG 31N TONIGHT THEN WEAKEN AND SHIFT E SUN AHEAD OF A COLD FRONT THAT WILL PASS THROUGH BERMUDA ON SUN NIGHT AND MOVE INTO THE CENTRAL ATLC MON. A BROAD SURFACE TROUGH S OF 25N ALONG 78W WILL AMPLIFY N ACROSS THE NW BAHAMAS ON SUN AND DRIFT W THROUGH THE FLORIDA STRAITS THROUGH MON NIGHT THEN INTO THE GULF OF MEXICO. FOR ADDITIONAL INFORMATION PLEASE VISIT HTTP://WWW.HURRICANES.GOV/MARINE $$ PAW