000 AXNT20 KNHC 121753 TWDAT TROPICAL WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 205 PM EDT TUE MAR 12 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 1200 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 1715 UTC. ...ITCZ/MONSOON TROUGH... THE MONSOON TROUGH EXTENDS FROM THE AFRICAN COAST NEAR 13N17W TO 06N20W TO 04N23W. THE INTERTROPICAL CONVERGENCE ZONE AXIS EXTENDS FROM 06N20W TO THE EQUATOR NEAR 29W. ISOLATED MODERATE CONVECTION IS FROM 01N-06N BETWEEN 13W-22W. ...DISCUSSION... GULF OF MEXICO... A MIDDLE TO UPPER LEVEL LONGWAVE TROUGH IS POSITIONED OVER THE EASTERN CONUS WITH MID-LEVEL ENENGY TRAILING S-SW ALONG THE TROUGH AXIS FROM OVER THE MID-ATLC STATES NEAR 38N77W TO OVER THE NE GULF WATERS NEAR 29N88W TO A BASE OVER NORTHERN MEXICO NEAR 25N99W. THIS FEATURE SUPPORTS A COLD FRONT ANALYZED FROM NORTHERN FLORIDA NEAR 30N83W TO THE NORTHERN YUCATAN PENINSULA COAST NEAR 22N88W AND ACROSS THE PENINSULA TO 19N91W. MOSAIC DOPPLER RADAR IMAGERY AND LIGHTNING DATA INDICATE WIDELY SCATTERED SHOWERS AND ISOLATED TSTMS OCCURRING WITHIN 120 NM EAST OF THE FRONT AND WITHIN 90 WEST OF THE FRONT. NORTH- NORTHEASTERLY WINDS SPREAD ACROSS MOST OF THE BASIN WEST OF THE FRONT WITH WINDS TAPERING TO LESS THAN 10 KT ACROSS PORTIONS OF THE NW GULF CLOSEST TO THE RIDGE AXIS WHICH IS ANCHORED BY A 1021 MB HIGH CENTERED OVER NW LOUISIANA NEAR 32N93W. THE RIDGE AXIS STRETCHES SOUTHWARD TO A 1022 MB HIGH NEAR THE MEXICO COAST NEAR 21N97W. THE FRONT IS EXPECTED TO SWEEP EAST OF THE BASIN THIS EVENING INTO EARLY WEDNESDAY WITH NORTHEAST WINDS DOMINATING THROUGH THURSDAY. CARIBBEAN SEA... WATER VAPOR IMAGERY INDICATES GENERALLY DRY AND STABLE WESTERLY FLOW ALOFT ACROSS THE ENTIRE BASIN WHICH IS PROVIDING FOR FAIR CONDITIONS AT THE SURFACE OVERALL E OF 84W. E-NE TRADES PERSIST OVER THIS REGION AS WELL WITH THE STRONGEST TRADES EXPECTED OVER THE CENTRAL PORTION OF THE CARIBBEAN S OF 17N BETWEEN 69W-79W... AND IN CLOSE PROXIMITY TO THE COAST OF COLOMBIA. W OF 84W...THE INFLUENCE OF A COLD FRONT ANALYZED ACROSS THE SE GULF OF MEXICO AND YUCATAN PENINSULA IS PROVIDING FOCUS FOR ISOLATED SHOWERS AND TSTMS WEST OF A LINE FROM WESTERN CUBA NEAR 22N84W TO THE COAST OF HONDURAS NEAR 16N87W. THE FRONT WILL PUSH INTO THE NW CARIBBEAN BY EARLY THURSDAY WITH STRONG N-NE WINDS FORECAST N OF 17N W OF 80W. ATLANTIC OCEAN... MIDDLE TO UPPER LEVEL MOISTURE CONTINUES TO INCREASE OVER THE SW NORTH ATLC AS THE UPPER LEVEL RIDGING WITH AXIS ALONG 20N75W TO 32N70W SHIFTS EASTWARD AND IS REPLACE BY AN APPROACHING UPPER LEVEL TROUGH AXIS OVER THE EAST COAST OF THE UNITED STATES. THE TROUGHING SUPPORTS A COLD FRONT CURRENTLY ANALYZED INLAND ACROSS THE CAROLINAS AND GEORGIA AND INTO THE EASTERN GULF OF MEXICO WITH WIDELY SCATTERED SHOWERS AND ISOLATED TSTMS OCCURRING N OF 27N W OF 74W. THE REMAINDER OF THE SW NORTH ATLC IS UNDER THE INFLUENCE OF A SURFACE RIDGE WITH AXIS FROM 20N70W TO BEYOND 32N67W. FARTHER EAST...A MIDDLE TO UPPER LEVEL LOW IS CENTERED NEAR 33N48W WITH PLENTY OF MID-LEVEL ENERGY SURROUNDING THE ALOFT LOW CENTER N OF 21N BETWEEN 40W-58W. THE SURFACE LOW...AT 998 MB...AND CENTERED NEAR 34N47W YIELDS TWO BOUNDARIES THAT ENTER THE DISCUSSION AREA. ONE SURFACE TROUGH IS ANALYZED FROM 31N39W TO 24N44W TO 15N54W WITH WIDELY SCATTERED SHOWERS AND ISOLATED TSTMS OCCURRING WITHIN 240 NM EAST OF THE BOUNDARY N OF 22N AND. THE SECONDARY SURFACE TROUGH IS FOUND FROM 32N47W TO 26N50W TO 23N55W WITH ISOLATED SHOWERS OCCURRING FROM 23N-27N BETWEEN 46W-53W. FINALLY...A SURFACE RIDGE DOMINATES ACROSS THE EASTERN ATLC ANCHORED BY A 1019 MB HIGH CENTERED WEST OF THE CANARY ISLANDS NEAR 29N21W. FOR ADDITIONAL INFORMATION PLEASE VISIT HTTP://WWW.HURRICANES.GOV/MARINE $$ HUFFMAN