000 AXNT20 KNHC 161039 TWDAT TROPICAL WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 805 AM EDT SAT MAR 16 2013 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 0600 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 1015 UTC. ...ITCZ/MONSOON TROUGH... THE INTERTROPICAL CONVERGENCE ZONE AXIS EXTENDS ALONG 4N20W 2N30W 1N40W 1N49W. CLUSTERS OF MODERATE TO ISOLATED STRONG CONVECTION ARE ALONG THE ITCZ E OF 41W AND EXTENDING ABOUT 200 NM S OF THE AXIS AND 100 NM N OF IT. SIMILAR CONVECTION IS WITHIN 240 NM S OF THE MONSOON TROUGH WHEREAS LIGHTER CONVECTION IS WITHIN 100 NM N OF THE AXIS. A CLUSTER OF MODERATE CONVECTION IS S OF 4N WEST OF 48W. ...DISCUSSION... GULF OF MEXICO... AS OF 0900 UTC...WATER VAPOR IMAGERY INDICATE DRY AIR ALOFT N OF 27N AND MOISTURE COVERING THE REST OF THE BASIN. THIS MOISTURE THAT CONTINUES BEING ADVECTED FROM THE E PACIFIC BY SOUTHWESTERLY FLOW IS SUPPORTING BROKEN SKIES S OF 27N. LIGHT FOG AND HAZE CONTINUE TO BE REPORTED ALONG THE SOUTHERN GULF COASTLINE FROM TUXPAN TO CAMPECHE AND THE GOES IR IMAGERY ENHANCEMENT AS WELL AS THE TOTAL PRECIPITABLE WATER INDICATE POSSIBLE ISOLATED SHOWERS OVER THIS REGION W OF 85W. RETURN FLOW HAS BUILT OVER THE BASIN ANCHORED BY A 1022 MB HIGH LOCATED OVER CENTRAL FLORIDA NEAR 27N81W. WIND MAGNITUDE IS IN THE RANGE OF 5- 15 KT BEING 10 KT PREDOMINANT. OVER THE COURSE OF 24 HOURS...RETURN FLOW WILL CONTINUE ACROSS THE BASIN AS A BROAD HIGH PRESSURE BUILDS OVER THE WEST ATLC. CARIBBEAN SEA... SOUTHWESTERLY FLOW IN THE MIDDLE TO UPPER LEVELS SURROUNDING A BROAD RIDGE WITH AXIS EXTENDING ALONG THE CENTRAL ATLC CONTINUES TO ADVECT MOISTURE FROM THE E PACIFIC AND S OF THE EQUATOR ACROSS MOST OF THE BASIN THIS MORNING. THIS MOISTURE IS SUPPORTING LOW LEVEL CLOUDINESS AND ENHANCING ISOLATED SHOWERS ACROSS THE CARIBBEAN WATERS. A SHEARLINE IS BEING ANALYZED ACROSS THE CENTRAL HISPANIOLA NEAR 18N73W 16N75W TO 13N77W. NORTHEASTERLY FLOW SPREADS OVER THE ENTIRE REGION WITH OBSERVED MAXIMUM WINDS OF 20-25 KT IMMEDIATELY WEST OF THE SHEARLINE... ALONG THE COAST OF COLOMBIA AS WELL AS THE CENTRAL CARIBBEAN WHERE A TIGHTER PRESURE GRADIENT HAS BUILT. THE SHEAR LINE IS EXPECTED TO BECOME DIFFUSE OVER THE NEXT 12 TO 24 HOURS AS A BROAD SURFACE RIDGE CURRENTLY OVER CENTRAL FLORIDA BUILDS EASTWARD INTO THE SW NORTH ATLC. AS THE TIGHTER PRESSURE GRADIENT CONTINUES OVER THE CENTRAL CARIBBEAN...EASTERLY TRADEWINDS OF 20-25 KT ARE EXPECTED TO REMAIN WHILE NEAR GALE FORCE WINDS MAY BE POSSIBLE ALONG THE COAST OF COLOMBIA. ATLANTIC OCEAN... A MIDDLE TO UPPER LEVEL TROUGH OVER THE NW NORTH ATLC WITH AXIS EXTENDING SOUTHWESTWARD TO 25N IS SUPPORTING A COLD FRONT THAT ENTERS THE DISCUSSION AREA NEAR 30N49W AND CONTINUES ALONG 24N56W 22N61W TO 20N64W WHERE IT TRANSITIONS TO A SHEARLINE. SCATTERED SHOWERS ARE N OF 27N BETWEEN 46W AND 54W...HOWEVER ISOLATED SHOWERS ARE POSSIBLE ALONG THE REMAINDER FRONTAL BOUNDARY. WITHIN THE COURSE OF 24 HOURS...THE COLD FRONT IS EXPECTED TO DISSIPATE WHILE A BROAD HIGH PRESSURE WILL BUILD OVER THE WEST ATLC. FOR ADDITIONAL INFORMATION PLEASE VISIT HTTP://WWW.HURRICANES.GOV/MARINE $$ NR