000 AXNT20 KNHC 262342 TWDAT TROPICAL WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 805 PM EDT MON MAR 26 2012 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 1800 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 2315 UTC. ...ITCZ/MONSOON TROUGH... THE MONSOON TROUGH EXTENDS FROM THE AFRICAN COAST NEAR 09N13W TO 04N21W. THE INTERTROPICAL CONVERGENCE ZONE AXIS EXTENDS FROM 04N21W TO THE EQUATOR NEAR 27W. ISOLATED MODERATE CONVECTION IS S OF 05N BETWEEN 06W-29W. ...DISCUSSION... GULF OF MEXICO... WATER VAPOR IMAGERY SHOWS AN UPPER LEVEL TROUGH MOVING EASTWARD OFF THE EASTERN U.S. SEABOARD AND INTO THE WESTERN ATLC PROVIDING THE GULF WITH DRY NORTHWEST TO WEST FLOW ALOFT AS AN UPPER LEVEL RIDGE WITH AXIS ALONG 95W BUILDS WESTWARD OVER THE GULF REGION THIS EVENING. WHILE THE MIDDLE TO UPPER LEVELS OF THE ATMOSPHERE PROMOTE STABLE CONDITIONS...AT THE SURFACE...A 1019 MB HIGH IS CENTERED IN THE NW GULF NEAR 28N94W AND CONTINUES TO PROVIDE LIGHT WINDS AND FAIR WEATHER CONDITIONS THIS EVENING INTO THE OVERNIGHT HOURS. A RECENT AFTERNOON ASCAT PASS CONFIRMS THE OVERALL LIGHT WIND REGIME WHILE THE LAST FEW VISIBLE SATELLITE IMAGES INDICATE CLEAR SKIES. THESE CONDITIONS SHOULD PERSIST THROUGH THE END OF THE WEEK AS THE SURFACE RIDGE SHIFTS EASTWARD INTO THE SW NORTH ATLC BY WEDNESDAY. CARIBBEAN SEA... SOUTH-SOUTHWESTERLY UPPER LEVEL FLOW PREVAILS OVER THE ENTIRE BASIN THIS EVENING ON THE NORTHWESTERN PERIPHERY OF AN UPPER LEVEL RIDGE WITH AXIS STEMMING FROM THE TROPICAL ATLC NEAR 04N40W TO 18N73W. HOWEVER...NORTH OF THIS RIDGE AXIS AN UPPER LEVEL TROUGH IS MOVING ACROSS THE SW NORTH ATLC AND EXTENDS A COLD FRONT ACROSS CENTRAL AND WESTERN CUBA FROM 22N79W TO 22N84W. A FEW ISOLATED LATE AFTERNOON SHOWERS AND TSTMS HAVE BLOSSOMED OVER CENTRAL CUBA AND THE ADJACENT CARIBBEAN WATERS DUE TO PEAK DAYTIME HEATING AND ARE FORECAST TO DIMINISH THROUGH THE EVENING HOURS. OTHERWISE...RELATIVELY WEAKER E-NE TRADES IN THE RANGE OF 10 TO 15 KT ARE OBSERVED ACROSS MUCH OF THE BASIN DUE TO THE FRONTAL TROUGHING PASSING TO THE NORTH OF 20N. AS THE FRONTAL TROUGH MOVES EAST-NORTHEAST INTO THE CENTRAL ATLC BY WEDNESDAY...HIGH PRESSURE IS EXPECTED TO MOVE OFF THE EASTERN CONUS AND SETTLE IN OVER THE SW NORTH ATLC PROVIDING FOR A GRADUAL INCREASE IN THE E-NE TRADES THROUGH THURSDAY. ALSO OF NOTE THIS EVENING...THE LAST FEW VISIBLE SATELLITE IMAGES OF THE DAY ALONG WITH GOES-R DUST ENHANCEMENT IMAGERY INDICATE THAT AN AREA OF AFRICAN DUST STRETCHES ACROSS THE TROPICAL ATLC AND HAVE REACHED PORTIONS OF THE EASTERN CARIBBEAN. RECENT OBSERVATIONS FROM SAINT VINCENT AND THE GRENADINES AND THE BRITISH VIRGIN ISLANDS HAVE REPORTED HAZY CONDITIONS THIS AFTERNOON. ATLANTIC OCEAN... AN UPPER LEVEL TROUGH IS OVER THE WESTERN ATLC WITH AXIS EXTENDING FROM THE CANADIAN MARITIMES SOUTHWARD TO NEAR 28N75W. THIS TROUGH SUPPORTS A 998 MB LOW CENTERED NORTH OF THE DISCUSSION AREA NEAR 38N67W THAT EXTENDS A COLD FRONT FROM THE LOW ALONG 32N67W TO 24N75W TO CENTRAL CUBA NEAR 22N79W. SCATTERED SHOWERS AND TSTMS ARE OCCURRING WITHIN 90 NM EITHER SIDE OF THE FRONT NORTH OF 25N. A SECONDARY PUSH OF ENERGY IS ANALYZED NW OF THE FRONT AS A SURFACE TROUGH FROM 32N74W TO THE NORTHERN FLORIDA COAST NEAR JACKSONVILLE WITH THE MAIN IMPACT OF SLIGHTLY STRONGER NORTHERLY WINDS THIS EVENING. THIS FRONT IS EXPECTED TO SLIDE EASTWARD INTO THE CENTRAL ATLC BY WEDNESDAY AS HIGH PRESSURE MOVES OFF THE EASTERN CONUS AND SETTLES INTO THE SW NORTH ATLC THE LATTER HALF OF THE WEEK. FARTHER EAST OVER THE REMAINDER OF THE CENTRAL AND EASTERN ATLC...SURFACE HIGH PRESSURE DOMINATES ANCHORED BY A 1022 MB HIGH CENTERED NEAR 34N46W. HOWEVER...AN UPPER LEVEL LOW AND ASSOCIATED TROUGH OVER THE NORTHEASTERN NORTH ATLC SUPPORTS A WEAKENING COLD FRONT ANALYZED ALONG 32N29W TO 26N40W TO 26N48W. WHILE NOT SIGNIFICANTLY CONVECTIVE DUE TO LACK OF UPPER LEVEL SUPPORT... ISOLATED SHOWERS ARE OCCURRING WITHIN 60 NM EITHER SIDE OF THE FRONT. FOR ADDITIONAL INFORMATION PLEASE VISIT HTTP://WWW.HURRICANES.GOV/MARINE $$ HUFFMAN