000 AXNT20 KNHC 210603 TWDAT TROPICAL WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 205 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 0000 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 0515 UTC. ...THE ITCZ/THE MONSOON TROUGH... THE MONSOON TROUGH PASSES THROUGH COASTAL GUINEA IN AFRICA NEAR 10N14W TO 6N16W AND 3N21W. THE ITCZ CONTINUES FROM 3N21W... CROSSING THE EQUATOR ALONG 31W...TO THE COAST OF NORTHEASTERN BRAZIL NEAR 3S41W. CONVECTIVE PRECIPITATION...SCATTERED STRONG TO THE SOUTH OF 2N TO THE EAST OF 4W AND IN AN AREA THAT IS BOUNDED BY 3N25W...TO THE EQUATOR ALONG 29W...TO 2N31W TO 4N27W AND 3N25W...ISOLATED MODERATE ELSEWHERE TO THE SOUTH OF 5N TO THE EAST OF 32W. ...DISCUSSION... THE GULF OF MEXICO... A DEEP LAYER TROUGH...THAT IS MOVING THROUGH TEXAS AND LOUISIANA AND THE WESTERN GULF OF MEXICO...SUPPORTS A COLD FRONT THAT PASSES THROUGH SOUTHWESTERN LOUISIANA...TO 28N95W IN THE NORTHWESTERN GULF OF MEXICO...TO THE DEEP SOUTH OF TEXAS... TO NORTHEASTERN MEXICO NEAR 25N99W. WIDELY SCATTERED MODERATE TO ISOLATED STRONG CONVECTIVE PRECIPITATION COVERS THE GULF OF MEXICO TO THE NORTHWEST OF 23N98W 25N90W 29N90W. A SEPARATE SURFACE TROUGH IS IN THE EASTERN GULF OF MEXICO ALONG 28N84W 24N86W TO 21N88W IN THE NORTHERN YUCATAN PENINSULA OF MEXICO. WIDELY SCATTERED TO SCATTERED MODERATE...TO ISOLATED STRONG... CONVECTIVE PRECIPITATION COVERS THE GULF OF MEXICO/FLORIDA/ THE ATLANTIC OCEAN TO THE EAST OF FLORIDA FROM 24N TO 30N BETWEEN 78W AND 87W. 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. THE CARIBBEAN SEA... PLEASE READ THE HIGH SEAS FORECAST...MIAHSFAT2...AND THE OFFSHORE FORECAST...MIAOFFNT3...FOR DETAILS ABOUT THE COLD FRONT IN ABOUT 30 HOURS OR SO AND THE 20 KNOT WIND SPEEDS THAT ARE EXPECTED TO ACCOMPANY IT. A SURFACE TROUGH IS ALONG 18N59W... ACROSS DOMINICA TO 14N62W...TO COASTAL VENEZUELA NEAR 11N63W. ISOLATED MODERATE CONVECTIVE PRECIPITATION IS FROM 12N TO 13N BETWEEN 59W AND 62W. BROAD UPPER LEVEL WESTERLY WIND FLOW COVERS THE AREA. A SURFACE RIDGE PASSES THROUGH 22N70W IN THE ATLANTIC OCEAN...ACROSS WESTERN HISPANIOLA...TO 17N76W TO THE SOUTHEAST OF JAMAICA. RAINSHOWERS ARE POSSIBLE IN THE SOUTHWESTERN CORNER OF THE AREA...TO THE SOUTH OF 14N TO THE WEST OF 80W...RELATED TO A SURFACE TROUGH THAT EXTENDS FROM THE SOUTHWESTERN CORNER OF THE CARIBBEAN SEA...ACROSS COSTA RICA...INTO THE EASTERN PACIFIC OCEAN. THE ATLANTIC OCEAN... A COLD FRONT...THAT NOW IS IN THE NORTHWESTERN GULF OF MEXICO... IS FORECAST TO MOVE OFF THE SOUTHEASTERN COAST OF THE U.S.A. BY SUNDAY. 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 11 FOOT SEA HEIGHTS...THAT ARE FORECAST TO REACH THE SOUTHEASTERN COAST OF THE U.S.A. BY SUNDAY. AN UPPER LEVEL TROUGH PASSES THROUGH 32N46W TO 27N48W. A COLD FRONT PASSES THROUGH 32N45W TO 31N46W. A SURFACE TROUGH CONTINUES FROM 31N46W TO 25N50W. RAINSHOWERS ARE POSSIBLE TO THE NORTH OF 22N 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 23N35W CYCLONIC CIRCULATION CENTER TO 16N43W. A 1026 MB HIGH PRESSURE CENTER IS NEAR 36N29W. ONE SURFACE RIDGE EXTENDS FROM THE HIGH CENTER TO 24N37W AND 18N48W. A SECOND RIDGE IS ALONG 26N27W 17N25W TO 7N21W. BROAD UPPER LEVEL CYCLONIC WIND FLOW IS TO THE NORTH AND NORTHEAST OF THE LINE THAT PASSES THROUGH 32N26W TO 25N18W AND 21N10W. FOR ADDITIONAL INFORMATION PLEASE VISIT HTTP://WWW.HURRICANES.GOV/MARINE $$ MT