000 AXNT20 KNHC 210605 TWDAT TROPICAL WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 805 AM EDT WED APR 20 2011 TROPICAL WEATHER DISCUSSION FOR NORTH AMERICA...CENTRAL AMERICA...GULF OF MEXICO...CARIBBEAN SEA...NORTHERN SECTION OF SOUTH AMERICA...AND ATLANTIC OCEAN TO THE AFRICAN COAST FROM THE EQUATOR TO 32N. THE FOLLOWING INFORMATION IS BASED ON SATELLITE IMAGERY...METEOROLOGICAL ANALYSIS...WEATHER OBSERVATIONS...AND RADAR. BASED ON 0600 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 1015 UTC. ...THE ITCZ... FROM LIBERIA NEAR 6N10W...CROSSING THE EQUATOR ALONG 18W...TO 4S25W AND INTO THE NORTHEASTERN BRAZIL COAST NEAR 5S36W. STRONG RAINSHOWERS AND THUNDERSTORMS ARE FROM THE EQUATOR TO 5N BETWEEN 4W AND 20W...AND FROM THE EQUATOR TO 2N BETWEEN 23W AND 26W. ISOLATED MODERATE RAINSHOWERS AND POSSIBLE THUNDERSTORMS ARE WITHIN 120 NM OF THE COAST BETWEEN 45W AND 56W. ...DISCUSSION... THE GULF OF MEXICO... MIDDLE LEVEL TO UPPER LEVEL WESTERLY WIND FLOW SPANS THE AREA. A FRONTAL BOUNDARY CUTS THROUGH TEXAS...FROM NORTHWESTERN LOUISIANA INTO CENTRAL TEXAS...CURVING TOWARD THE FAR WEST OF TEXAS...AND THEN NORTHWARD INTO CENTRAL NEW MEXICO. THE SURFACE PRESSURE GRADIENT BETWEEN THE HIGH PRESSURE THAT IS IN THE EASTERN GULF OF MEXICO...AND THE BROAD LOW PRESSURE WITH THE FRONTAL BOUNDARY WILL RESULT IN MODERATE TO FRESH SOUTHEASTERLY RETURN FLOW IN THE GULF OF MEXICO UNTIL AT LEAST MONDAY OF THE NEXT WEEK. THE CARIBBEAN SEA... BROAD UPPER LEVEL SOUTHWESTERLY WIND FLOW COVERS THE AREA. RAINSHOWERS ARE POSSIBLE IN SMALL CLUSTERS OF LOW CLOUDS... MOSTLY FROM 16N TO 19N BETWEEN 60W AND 75W...AND STILL POSSIBLE ELSEWHERE TO THE WEST OF 75W.LIKELY THE ATLANTIC OCEAN... BROAD UPPER LEVEL CYCLONIC FLOW COVERS THE ATLANTIC OCEAN TO THE NORTH OF 20N BETWEEN 50W AND 80W. A 1010 MB LOW PRESSURE CENTER IS NEAR 23N62W. ONE SHEAR AXIS IS ALONG 22N67W 23N72W 27N73W. A SECOND SHEAR AXIS IS ALONG 20N54W 23N57W 23N61W. EACH SHEAR AXIS IS A BOUNDARY THAT SEPARATES WIND SPEEDS THAT RANGE FROM 20 TO 25 KT ON THE EASTERN SIDE OF IT FROM WIND SPEEDS THAT ARE IN THE 10 TO 15 KT RANGE. SCATTERED MODERATE RAINSHOWERS TO ISOLATED STRONG THUNDERSTORMS ARE FROM 23N TO 27N BETWEEN 57W AND 63W. ISOLATED MODERATE RAINSHOWERS ARE ELSEWHERE TO THE NORTH OF 16N BETWEEN 50W AND 60W...AND FROM 22N TO 28N BETWEEN 60W AND 75W. AN UPPER LEVEL CYCLONIC CIRCULATION CENTER IS NEAR 36N13W. THIS CYCLONIC CENTER SUPPORTS A COLD FRONT THAT PASSES THROUGH 31N12W TO JUST TO THE NORTH OF THE CANARY ISLANDS... BEYOND 31N21W. RAINSHOWERS ARE POSSIBLE WITHIN 60 NM ON EITHER SIDE OF THE COLD FRONT. A SURFACE RIDGE EXTENDS FROM A 1031 MB HIGH PRESSURE CENTER THAT IS NEAR 35N41W TO 20N32W AND 5N20W. A SECOND SURFACE RIDGE EXTENDS FROM THE SAME 1031 MB HIGH PRESSURE CENTER THAT IS NEAR 35N41W TO A 1030 MB HIGH PRESSURE CENTER THAT IS NEAR 36N50W...TO 34N62W...TO A 1022 MB HIGH PRESSURE CENTER THAT IS NEAR 29N78W. FOR ADDITIONAL INFORMATION PLEASE VISIT HTTP://WWW.HURRICANES.GOV/MARINE $$ MT