000 AXNT20 KNHC 211151 TWDAT TROPICAL WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 805 AM EDT SAT APR 21 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 PASSES THROUGH COASTAL LIBERIA IN AFRICA NEAR 6N11W TO 5N12W AND 4N16W. THE ITCZ CONTINUES FROM 4N16W...CROSSING THE EQUATOR ALONG 23W...TO 3S32W. CONVECTIVE PRECIPITATION...SCATTERED MODERATE TO ISOLATED STRONG IS TO THE SOUTH OF 3N TO THE EAST OF 5W...AND TO THE SOUTH OF 4N BETWEEN 20W AND 35W. ISOLATED MODERATE ELSEWHERE TO THE SOUTH OF 5N TO THE EAST OF 32W. ...DISCUSSION... GULF OF MEXICO... A DEEP LAYER TROUGH...THAT IS MOVING THROUGH EAST TEXAS AND LOUISIANA AND THE WESTERN GULF OF MEXICO...SUPPORTS A COLD FRONT THAT PASSES THROUGH SOUTH CENTRAL LOUISIANA...TO 25N94W IN THE NORTHWESTERN GULF OF MEXICO...INTO NORTHEASTERN MEXICO NEAR 24N98W. WIDELY SCATTERED MODERATE TO ISOLATED STRONG CONVECTIVE PRECIPITATION COVERS THE GULF OF MEXICO TO THE SOUTH OF 24N TO THE WEST OF 94W. SCATTERED MODERATE TO ISOLATED STRONG CONVECTIVE PRECIPITATION IS IN THE SOUTHEASTERN CORNER FROM 24N TO 26N TO THE EAST OF 86W. SCATTERED MODERATE TO STRONG CONVECTIVE PRECIPITATION IS TO THE NORTH OF 25N BETWEEN 87W AND 89W. NORTHWEST OF 23N98W 25N90W 29N90W. A SEPARATE SURFACE TROUGH IS IN THE EASTERN GULF OF MEXICO ALONG 26N86 22N88W TO 18N89W IN THE SOUTHERN YUCATAN PENINSULA OF MEXICO. RAINSHOWERS WITH THUNDER ALSO ARE POSSIBLE IN THE ATLANTIC OCEAN TO THE NORTH OF ANDROS ISLAND IN THE BAHAMAS NEAR 24N TO THE WEST OF 77W. THE FORECAST FOR THE NEXT 24 TO 36 HOURS IS THAT THE UPPER LEVEL TROUGH WILL DEEPEN. MORE RAINSHOWERS AND THUNDERSTORMS WILL DEVELOP IN THE EASTERN GULF OF MEXICO AND IN FLORIDA TODAY. IT IS POSSIBLE THAT SEVERE WEATHER MAY DEVELOP IN THE EASTERN GULF OF MEXICO. THE COLD FRONT IS FORECAST TO MOVE EASTWARD RAPIDLY DURING THE NEXT 24 HOURS OR SO. PLEASE READ THE HIGH SEAS FORECAST...MIAHSFAT2...AND/OR THE OFFSHORE FORECAST... MIAOFFNT4...FOR DETAILS ABOUT THE FORECAST MOVEMENT OF THE COLD FRONT...AND THE 20 TO 30 KNOT WINDS AND 8 TO 12 FOOT SEA HEIGHTS THAT WILL BE RELATED TO THE COLD FRONT. CARIBBEAN SEA... PLEASE READ THE HIGH SEAS FORECAST...MIAHSFAT2...AND THE OFFSHORE FORECAST...MIAOFFNT3...FOR DETAILS ABOUT THE COLD FRONT IN ABOUT 24 HOURS OR SO AND THE 20 KNOT WIND SPEEDS THAT ARE EXPECTED TO ACCOMPANY IT. A SURFACE TROUGH IS ALONG 64W/65W FROM 11N TO 19N. ISOLATED MODERATE CONVECTIVE PRECIPITATION IS FROM 12N TO 20N BETWEEN 60W AND 70W. BROAD UPPER LEVEL WESTERLY WIND FLOW COVERS THE AREA. A SURFACE RIDGE PASSES THROUGH 26N70W TO JAMAICA. RAINSHOWERS ARE POSSIBLE IN THE SOUTHWESTERN CORNER OF THE AREA...TO THE SOUTH OF 15N TO THE WEST OF 79W...RELATED TO A SURFACE TROUGH AND ATMOSPHERIC INSTABILITY THAT EXTEND FROM THE SOUTHWESTERN CORNER OF THE CARIBBEAN SEA...ACROSS COSTA RICA AND SOUTHERN NICARAGUA...INTO THE EASTERN PACIFIC OCEAN. ATLANTIC OCEAN... A COLD FRONT...THAT NOW IS IN THE WEST CENTRAL GULF OF MEXICO... IS FORECAST TO MOVE OFF THE SOUTHEASTERN COAST OF THE U.S.A. DURING THE NEXT 24 HOURS. PLEASE READ THE ATLANTIC OCEAN HIGH SEAS FORECAST... MIAHSFAT2...FOR DETAILS ABOUT THE COLD FRONT AND 20 TO 30 KNOT WIND SPEEDS AND THE 8 TO 12 FOOT SEA HEIGHTS...THAT ARE FORECAST TO BE OCCURRING NEAR THE FRONT. AN UPPER LEVEL TROUGH PASSES THROUGH 32N42W TO 26N48W. A COLD FRONT PASSES THROUGH 32N45W TO 31N46W. A SURFACE TROUGH CONTINUES FROM 31N46W TO 25N50W. RAINSHOWERS ARE POSSIBLE TO THE NORTH OF 20N BETWEEN 40W AND 50W. PLEASE READ THE ATLANTIC OCEAN HIGH SEAS FORECAST...MIAHSFAT2...FOR DETAILS ABOUT THE 20 KNOT WINDS THAT ARE NEAR THE CENTRAL ATLANTIC FRONTAL BOUNDARY. SURFACE ANTICYCLONIC WIND FLOW IS TO THE WEST OF THE 32N45W 25N50W FRONTAL BOUNDARY. THIS ANTICYCLONIC WIND FLOW MOVES AROUND A 1020 MB HIGH PRESSURE CENTER THAT IS NEAR 33N63W... TO THE NORTH OF 20N TO THE WEST OF 63W. AN UPPER LEVEL TROUGH EXTENDS FROM A 22N34W CYCLONIC CIRCULATION CENTER TO 15N40W. A 1026 MB HIGH PRESSURE CENTER IS NEAR 36N28W. ONE SURFACE RIDGE EXTENDS FROM THE HIGH CENTER TO 26N32W 17N38W AND 10N40W. A SECOND RIDGE IS ALONG 27N23W 19N21W TO 11N19W. BROAD UPPER LEVEL CYCLONIC WIND FLOW IS TO THE NORTH AND NORTHEAST OF THE LINE THAT PASSES THROUGH 32N27W TO 24N20W AND 21N10W. FOR ADDITIONAL INFORMATION PLEASE VISIT HTTP://WWW.HURRICANES.GOV/MARINE $$ MT