000 AXNT20 KNHC 201049 TWDAT TROPICAL WEATHER DISCUSSION NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL 805 AM EDT TUE APR 20 2010 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...METEOROLOGICAL ANALYSIS...WEATHER OBSERVATIONS...AND RADAR. BASED ON 0600 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 1045 UTC... ...THE ITCZ... THE ITCZ IS ANALYZED FROM THE SOUTHERN COAST OF LIBERIA NEAR 5N8W...WESTWARD ALONG 1N20W CONTINUING ACROSS THE EQUATOR TO 50W. WIDELY SCATTERED MODERATE TO STRONG CONVECTION IS WITHIN 150 NM ON EITHER SIDE OF THE AXIS. ...DISCUSSION... THE GULF OF MEXICO... AN UPPER LEVEL SHORTWAVE IS ENTERING THE WESTERN GULF. STRONG LIFTING AHEAD OF THIS FEATURE IS PRODUCING MODERATE TO HEAVY SHOWERS WEST OF 94W...EXPECTED TO LINGER THROUGH TUESDAY LATE NIGHT. A STATIONARY FRONT IS ALONG THE NORTHERN GULF COAST FROM EASTERN LOUISIANA TO THE WESTERN FLORIDA PANHANDLE. SCATTERED WEAK TO MODERATE SHOWERS ARE WITHIN 50 NM ON EITHER SIDE OF THE FRONT. THIS FRONT IS BEEN RE-ENFORCED BY THE UPPER LEVEL SHORTWAVE...EXPECTED TO BECOME A COLD FRONT AND MOVE EASTWARD ACROSS THE NORTH CENTRAL GULF OVER THE NEXT 6 TO 9 HOURS. REMNANT SHOWERS FROM A FRONTAL BOUNDARY AND SURFACE LOW THAT MOVED ACROSS THE FLORIDA PENINSULA OVER THE PAST 24 HOURS ARE STILL AFFECTING THE STATE SOUTH OF 29N. EXPECT INSTABILITY IN THIS REGION WITH SHOWERS LINGERING THROUGH WEDNESDAY AFTERNOON. A STABLE AIRMASS DOMINATES ELSEWHERE ACROSS THE REGION. THE CARIBBEAN SEA... WATER VAPOR IMAGERY SHOWS A BROAD AREA OF MID LEVEL MOISTURE MOVING NORTHEAST ACROSS THE CENTRAL AND EASTERN CARIBBEAN EAST OF 80W. BEHIND THIS AREA OF MID LEVEL MOISTURE LIES AN UPPER LEVEL SHORTWAVE THAT SUPPORTS A SURFACE TROUGH THAT EXTENDS SOUTHWEST FROM THE SOUTHERN BAHAMAS CROSSING WESTERN HAITI TO NEAR 15N77W. SCATTERED SHOWERS ARE WITHIN 80 NM ON EITHER SIDE OF THE TROUGH. SIMILAR CONVECTION IS ALSO FOUND WITHIN 110 NM OFF THE COAST OF COLOMBIA AND VENEZUELA WEST OF 68W. THIS TROUGH IS EXPECTED TO CONTINUE TO MOVE EASTWARD WITH CONVECTION AFFECTING THE EASTERN BASIN EAST OF 70W THROUGHOUT THE WORK WEEK. REMNANTS OF A FRONTAL BOUNDARY CONTINUE TO PRODUCE WEAK TO MODERATE SHOWERS EAST OF 67W AFFECTING MOSTLY THE LESSER ANTILLES SOUTH OF 14N. COMPUTER MODELS SUGGEST THIS AREA OF CONVECTION WILL LINGER THROUGH THURSDAY NIGHT. THE ATLANTIC OCEAN... AN UPPER LEVEL SHORTWAVE IS MOVING ACROSS THE WESTERN ATLANTIC SUPPORTING A COLD FRONT THAT ENTERS THE DISCUSSION AREA NEAR 32N58W CONTINUING SOUTHWEST TO A LOW PRESSURE CENTER NEAR 30N61W. THE COLD FRONT CONTINUES TO EXTEND SOUTHWEST FROM THE LOW CENTER TO THE CENTRAL BAHAMAS NEAR 23N75W. SHOWERS ARE POSSIBLE WITHIN 120 NM ON EITHER SIDE OF THE FRONT. TO THE EAST OF THIS FRONT LIES A SURFACE HIGH PRESSURE SYSTEM NEAR 28N42W DOMINATING THE CENTRAL ATLANTIC NORTH OF 15N BETWEEN 30W AND 60W. THIS SURFACE HIGH IS SUPPORTED BY A BROAD UPPER LEVEL RIDGE THAT COVERS THE ATLANTIC FROM 30W TO 70W. OVER THE EASTERN ATLANTIC...A WEAKENING COLD FRONT ENTERS THE DISCUSSION AREA THROUGH 32N16W CONTINUING SOUTHWEST ACROSS THE SOUTH CENTRAL ATLANTIC ALONG 25N18W 20N25W BECOMING STATIONARY TO NEAR 15N40W CONTINUING AS A SHEAR LINE TO NEAR 15N52W. SCATTERED WEAK TO MODERATE SHOWERS ARE WITHIN 50 NM EITHER SIDE OF THE COLD FRONT AND STATIONARY FRONT. THE SHEAR LINE IS GENERATING A BROAD AREA OF WEAK TO MODERATE SHOWERS COVERING FROM 12N TO 18N BETWEEN 40W AND 52W. AS THE EASTERN ATLANTIC COLD FRONT CONTINUES TO WEAKEN AND MOVE EASTWARD...COMPUTER MODELS HINT THE CONVECTION GENERATED BY THE SHEAR LINE MAY LINGER NEAR THE MENTIONED AREA THROUGH WEDNESDAY NIGHT. FOR ADDITIONAL INFORMATION PLEASE VISIT HTTP://WWW.HURRICANES.GOV/MARINE $$ GARCIA