000 AXNT20 KNHC 162349 TWDAT TROPICAL WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 805 PM EDT WED MAR 16 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 1800 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 2345 UTC. ...THE ITCZ... THE ITCZ AXIS IS ANALYZED FROM 05N08W TO THE EQUATOR AT 28W CONTINUING SW AND INLAND SOUTH AMERICA AT 04S39W. SCATTERED MODERATE AND ISOLATED STRONG CONVECTION IS NOTED WITHIN 30 NM EITHER SIDE OF A LINE FROM 05N11W TO 04N18W TO 02N25W. ...DISCUSSION... GULF OF MEXICO... AN UPPER LEVEL TROUGH IS SWINGING EAST ACROSS THE EASTERN UNITED STATES TRAILING ITS SOUTHERN EXTENSION DIAGONALLY ACROSS THE GULF OF MEXICO FROM THE FLORIDA BIG BEND TO SOUTHEAST TEXAS. AN ASSOCIATED SURFACE FRONT IS WASHING OUT OVER THE NORTHWEST WATERS...BUT IS STILL ACCOMPANIED BY A FEW SHOWERS. SOME UPPER MOISTURE IS JUST BEGINNING TO SPREAD EAST OVER THE NORTHEAST TEXAS AND SOUTHERN LOUISIANA COASTAL PLAINS. THIN CIRRIFORM CLOUDS ARE NOTED OVER THE SOUTHWEST PORTION. UPPER DEBRIS MOISTURE IS NOTED FROM FRONTAL CONVECTION NEAR 27N87W. OTHERWISE...THE UPPER LEVELS APPEAR DRY. A WEAK LOW LEVEL TROUGH IS MOVING SLOWLY WEST ACROSS THE CENTRAL BAY OF CAMPECHE ACCOMPANIED BY TOWERING CUMULUS AND LIGHT SHOWERS. CARIBBEAN SEA... AN UPPER LEVEL ANTICYCLONE IS CENTERED OVER THE DEEP TROPICAL ATLANTIC AT 12N53W...RIDGING WEST NORTHWEST ACROSS THE CARIBBEAN FROM THE EXTREME SOUTHEAST WINDWARDS TO NEAR THE YUCATAN CHANNEL. THIN CIRRIFORM CLOUDS ARE RACING NORTHEAST ALONG THE PERIPHERY OF THIS RIDGE...OVER THE NORTHWEST PORTION OF THE DISCUSSION AREA. SIMILAR CLOUDS ARE ALSO NOTED OVER THE CENTRAL CARIBBEAN. AT THE LOW LEVELS ATLANTIC HIGH PRESSURE IS MAINTAINING EAST NORTHEAST TRADES AT 10 TO 15 KT...EXCEPT 20 TO 25 KT ALONG THE NORTHWEST COAST OF COLOMBIA. EMBEDDED SHOWERS ACCOMPANY THE TRADES WITH THE MOST SIGNIFICANT CLUSTERS OF SHOWERS ALONG A BAND EXTENDING EAST TO WEST OVER THE CENTRAL CARIBBEAN CONTINUING INLAND BELIZE. ATLANTIC OCEAN... AN UPPER LEVEL TROUGH IS MOVING OFF THE EASTERN CONUS ACCOMPANIED BY A WEAK COLD FRONT OVER THE ATLANTIC WATERS JUST E OF NORTH FLORIDA WITH VERY LITTLE CONVECTION REMAINING ALONG THE SURFACE FRONT. SOME UPPER MOISTURE IS NOTED ALONG A NARROW BAND FROM CENTRAL FLORIDA TO BEYOND 32N WHERE THE MOISTURE FANS OUT AS IT CONTINUES EAST AND SHOULD SOON MOVE OVER BERMUDA. A SECOND UPPER TROUGH IS SWINGING EAST OVER THE CENTRAL ATLANTIC NORTH OF 25N BETWEEN 50W AND 35W. THE ASSOCIATED SURFACE FRONT IS BECOMING BROAD AS IT DISSIPATES FROM 32N41W TO NEAR 26N60W...WITH A FEW SHOWERS ENHANCED ALONG A PRE-FRONTAL TROUGH EXTENDING ALONG 32N37W TO 27N44W. UPPER MOISTURE FROM THIS CONVECTION SPREADS EAST MERGING WITH ABUNDANT UPPER MOISTURE OVER THE ATLANTIC NORTH OF 23N EXTENDING EAST TO OVER THE NORTHWEST AFRICAN COAST. AN UPPER TROUGH EXTENDS SW INTO THE EASTERN PORTION ALONG 32N12W TO 17N28W. DRY UPPER AIR IS INDICATED OVER THE TROPICS FROM 10N TO 23N E OF BAHAMAS TO OVER AFRICA AT 16W. A PERSISTENT AND BROAD LOW LEVEL TROUGH...ACCOMPANIED BY LOCALLY OVERCAST LOW AND MID LEVEL CLOUDS AND A FEW SHOWERS...IS NOTED OVER THE CENTRAL TROPICAL ATLANTIC FROM 26N46W TO 15N53W...BUT ITS NOT CERTAIN IF EXTENDS DOWN TO THE SURFACE NEAR 24N. FOR ADDITIONAL INFORMATION PLEASE VISIT HTTP://WWW.HURRICANES.GOV/MARINE $$ NELSON