000 AXNT20 KNHC 050545 TWDAT TROPICAL WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 105 AM EST TUE MAR 05 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 0000 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 0515 UTC. ...ITCZ/MONSOON TROUGH... THE MONSOON TROUGH EXTENDS FROM THE AFRICAN COAST NEAR 07N12W TO 05N16W. THE INTERTROPICAL CONVERGENCE ZONE AXIS EXTENDS FROM 05N16W TO 02N36W TO THE EQUATOR NEAR 43W. SCATTERED MODERATE CONVECTION IS S OF 04N BETWEEN 23W-34W. ...DISCUSSION... GULF OF MEXICO... WATER VAPOR IMAGERY INDICATES AN UPPER LEVEL TROUGH IS OVER THE BASIN WITH TROUGH AXIS EXTENDING FROM THE NE GULF NEAR 29N85W SW TO A BASE OVER CENTRAL MEXICO NEAR 21N100W. MOSTLY DRY AIR AND OVERALL SUBSIDENCE IS NOTED ALOFT WHICH FURTHER SUPPORTS A SURFACE RIDGE ANCHORED BY A 1022 MB HIGH CENTERED OVER THE CENTRAL FLORIDA PENINSULA NEAR 28N81W. SOUTHERLY RETURN FLOW DOMINATES ON THE WESTERN PERIPHERY OF THE RIDGE WITH THE STRONGEST WINDS...IN THE RANGE OF 20 TO 25 KT LOCATED NW OF A LINE FROM 30N85W TO 20N96W. THE RETURN FLOW IS EXPECTED TO PERSIST THROUGH TUESDAY UNTIL THE NEXT COLD FRONT EMERGES FROM THE TEXAS AND LOUISIANA COAST BY LATE TUESDAY INTO EARLY WEDNESDAY. THEREAFTER...ANOTHER ROUND OF NORTHERLY WINDS WILL FOLLOW IN WAKE OF THE COLD FRONT AS THE DEVELOPING LOW PRESSURE AREA SKIRTS ACROSS THE SE CONUS TO THE MID-ATLC COAST. CARIBBEAN SEA... AN UPPER LEVEL ANTICYCLONIC CIRCULATION IS CENTERED OVER VENEZUELA NEAR 07N64W WHICH IS PROVIDING THE ENTIRE CARIBBEAN BASIN WITH SOUTHWEST TO WESTERLY FLOW ALOFT. WHILE UPPER LEVEL MOISTURE CONTINUES TO STREAM NORTHEASTWARD FROM THE EAST PACIFIC AND NORTHERN SOUTH AMERICAN CONTINENT...LOW-LEVEL MOISTURE IS FOCUSED MAINLY WEST OF A FRONTAL BOUNDARY ANALYZED AS A COLD FRONT FROM 20N63W IN THE ATLC OCEAN TO 17N68W SOUTH OF PUERTO RICO...THEN MEANDERS SW AS A STATIONARY FRONT ALONG 17N68W TO 15N74W TO 09N78W. LOW-TOPPED ISOLATED SHOWERS ARE NOTED ON SATELLITE IMAGERY N OF 16N BETWEEN 64W-74W...S OF 20N BETWEEN 74W-80W...AND S OF 15N BETWEEN 80W AND 86W...INCLUDING PORTIONS OF INLAND NICARAGUA AND COSTA RICA. LOOKING AHEAD...THE FRONTAL BOUNDARY WILL CONTINUE TO BECOME MORE DIFFUSE THROUGH LATE TUESDAY WITH THE USUAL E-NE TRADE WINDS EXPECTED TO RE-ESTABLISH THEMSELVES BY WEDNESDAY AS A RIDGE SETTLES IN OVER THE SW NORTH ATLC TO THE NORTH. ATLANTIC OCEAN... A MIDDLE TO UPPER LEVEL LOW IS CENTERED OFFSHORE OF THE NEW ENGLAND COAST NEAR 44N65W THAT SUPPORTS A COLD FRONT ANALYZED INTO THE DISCUSSION AREA NEAR 32N43W. THE FRONT EXTENDS SW ALONG 29N50W TO 22N60W TO EASTERN PUERTO RICO NEAR 18N66W AND INTO THE CENTRAL CARIBBEAN SEA. ISOLATED SHOWERS AND TSTMS ARE OCCURRING WITHIN 150 NM EAST OF THE FRONT NORTH OF 23N AND WITHIN 180 NM WEST OF THE FRONT. AN UPPER LEVEL SHORTWAVE TROUGH IS NOTED ON WATER VAPOR IMAGERY IN THE VICINITY OF 33N64W THAT SUPPORTS A SECONDARY SURGE OF COLD AIR ACROSS THE SW NORTH ATLC ANALYZED AT THE SURFACE AS A TROUGH FROM 32N62W SW TO 26N71W. NW WINDS OF GALE FORCE WERE NOTED ON A RECENT ASCAT PASS AROUND 05/0128 UTC. OTHERWISE...THE REMAINDER OF THE SW NORTH ATLC W OF 73W IS UNDER THE INFLUENCE OF A SURFACE RIDGE ANCHORED BY A 1022 MB HIGH CENTERED OVER THE CENTRAL FLORIDA PENINSULA NEAR 28N81W. FARTHER EAST OVER THE CENTRAL ATLC AND PORTIONS OF THE EASTERN ATLC...ANOTHER BROAD SURFACE RIDGE DOMINATES AS A 1019 MB HIGH IS CENTERED NEAR 21N45W. THE ONLY EXCEPTION TO THE RIDGE IS A COLD FRONT THAT CONTINUES TO EXIT THE OCEAN BASIN MOVING EASTWARD AND INLAND OVER NORTHWESTERN AFRICA. THE FRONT IS ANALYZED FROM NORTHERN MOROCCO NEAR 32N06W TO 20N19W JUST OFFSHORE OF THE WESTERN SAHARA COAST. FOR ADDITIONAL INFORMATION PLEASE VISIT HTTP://WWW.HURRICANES.GOV/MARINE $$ HUFFMAN