000 AXNT20 KNHC 200553 TWDAT TROPICAL WEATHER DISCUSSION NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL 205 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 0000 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 0550 UTC... ...THE ITCZ... THE ITCZ IS ANALYZED FROM THE CENTRAL COAST OF LIBERIA NEAR 5N10W...WESTWARD ALONG 2N20W ACROSS THE EQUATOR TO 50W. WIDELY SCATTERED MODERATE TO STRONG CONVECTION ARE WITHIN 150 NM ON EITHER SIDE OF THE AXIS FROM 15W TO 45W. ...DISCUSSION... THE GULF OF MEXICO... AN UPPER LEVEL TROUGH IS CROSSING THE SIERRA MADRE MOUNTAINS NORTH OF 23N AND WILL BE ENTERING THE NORTHWEST GULF OVER THE NEXT 6 TO 12 HOURS. THEREFORE...LOOK FOR SHOWERS DEVELOPING NORTH OF 23N AND WEST OF 94W LASTING THROUGH TUESDAY NIGHT. A WEAK SURFACE TROUGH IS ANALYZED OVER THE WESTERN GULF ALONG 95W FROM 29N TO 24N CONTINUING SOUTHWARD AS A SHEAR LINE TO NEAR 21N. WEAK ISOLATED SHOWERS ARE FOUND WITHIN 40 NM OF THE TROUGH AND 12 NM OF THE SHEAR LINE. THIS TROUGH IS EXPECTED TO DISSIPATE OVER THE NEXT 8 HOURS. A DISSIPATING STATIONARY FRONT IS ALONG THE NORTHERN GULF COAST FROM WESTERN LOUISIANA TO THE WESTERN FLORIDA PANHANDLE. SCATTERED WEAK TO MODERATE SHOWERS ARE WITHIN 50 NM ON EITHER SIDE OF THE FRONT. THIS FRONT IS QUICKLY WEAKENING AND THE ACTIVITY RELATED THIS SYSTEM IS EXPECTED TO LESSEN OVER THE NEXT 6 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. THE CARIBBEAN SEA... WATER VAPOR IMAGERY SHOWS A BROAD AREA OF MID LEVEL MOISTURE IS 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 EASTERN CUBA AND CENTRAL JAMAICA TO NEAR 15N80W. SCATTERED SHOWERS ARE WITHIN 180 NM EAST OF THE TROUGH. SIMILAR CONVECTION IS ALSO FOUND WITHIN 130 NM OFF THE COAST OF COLOMBIA AND VENEZUELA EAST OF 67W. 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 AND PUERTO RICO. COMPUTER MODELS SUGGEST THIS AREA OF CONVECTION WILL LINGER THROUGH THURSDAY NIGHT. THE ATLANTIC OCEAN... AN UPPER LEVEL SHORTWAVE IS MOVING ACROSS THE FAR WESTERN ATLANTIC SUPPORTING A COLD FRONT THAT ENTERS THE DISCUSSION AREA NEAR 32N60W CONTINUING SOUTHWEST TO A LOW PRESSURE CENTER NEAR 27N64W. THE COLD FRONT CONTINUES TO EXTEND SOUTHWEST FROM THE LOW CENTER TO THE CENTRAL BAHAMAS NEAR 24N75W. 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 27N44W 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 25W TO 70W. OVER THE EASTERN ATLANTIC...A WEAKENING COLD FRONT ENTERS THE DISCUSSION AREA THROUGH 32N16W CONTINUING SOUTHWEST TO THE SOUTH CENTRAL ATLANTIC ALONG 22N24W 18N30W 15N40W CONTINUING AS A SHEAR LINE TO NEAR 14N50W. SCATTERED WEAK TO MODERATE SHOWERS ARE WITHIN 50 NM EITHER SIDE OF THE COLD FRONT. THE SHEAR LINE IS GENERATING A BROAD AREA OF WEAK TO MODERATE SHOWERS COVERING FROM 10N TO 20N BETWEEN 40W AND 60W. THIS AREA EXTENDS AS FAR WEST AS THE LESSER ANTILLES. 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