000 AXNT20 KNHC 272348 TWDAT TROPICAL WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 705 PM EST MON FEB 27 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 07N11W TO 03N21W. THE INTERTROPICAL CONVERGENCE ZONE AXIS EXTENDS FROM 03N21W TO THE EQUATOR NEAR 33W TO 01N42W TO THE EQUATOR NEAR 47W. ISOLATED MODERATE CONVECTION IS FROM 01N-06N BETWEEN 35W-52W. ...DISCUSSION... GULF OF MEXICO... AN UPPER LEVEL SHORTWAVE TROUGH HAS MOVED OFF THE NE FLORIDA COAST WITH AXIS EXTENDING FROM 31N81W TO 23N76W OVER THE CENTRAL BAHAMAS. THIS WEAK MIDDLE TO UPPER LEVEL FEATURE CONTINUES TO SUPPORT A SURFACE TROUGH ANALYZED FROM JACKSONVILLE FLORIDA TO 30N84W TO 27N94W. MOSAIC DOPPLER RADAR IMAGERY AND LIGHTNING DATA INDICATE SCATTERED SHOWERS AND ISOLATED TSTMS ARE OCCURRING OVER INLAND PORTIONS OF THE FLORIDA PENINSULA AND PANHANDLE THIS EVENING AS WELL AS N OF 28N BETWEEN 86W-91W IN THE VICINITY OF THE MISSISSIPPI RIVER DELTA REGION. ELSEWHERE ISOLATED SHOWERS ARE OCCURRING N OF 27N W OF 91W ACROSS THE NW GULF WATERS. THE REMAINDER OF THE GULF IS UNDER THE INFLUENCE OF AN UPPER LEVEL RIDGE WITH AXIS ALONG 95W. AT THE SURFACE BENEATH THIS RIDGING...LIGHT SOUTH-SOUTHEASTERLY FLOW IS NOTED SOUTH OF THE SURFACE TROUGH AXIS WITH CLEAR SKIES AND MOSTLY FAIR CONDITIONS THIS EVENING. AS THE BOUNDARY CONTINUES TO WEAKEN OVER THE NEXT 24 TO 36 HOURS...SURFACE RIDGING IS ONCE AGAIN EXPECTED TO BUILD IN ACROSS THE GULF PROVIDING MODERATE EAST TO SOUTHEAST WINDS E OF 95W. W OF 95W...SOUTHERLY WINDS WILL REMAIN MODERATE TO FRESH AS AN INTENSE LOW PRESSURE AREA MOVES ACROSS THE NORTHERN PLAINS INTO THE GREAT LAKES REGION BY MID-WEEK. CARIBBEAN SEA... CONDITIONS ACROSS THE CARIBBEAN REMAIN FAIRLY TRANQUIL THIS EVENING DUE TO VERY DRY AND SUBSIDENT AIR ALOFT AS NOTED ON WATER VAPOR IMAGERY. AN UPPER LEVEL TROUGH AXIS EXTENDS ALONG 78W BUT IS HAVING LITTLE EFFECT ON SENSIBLE WEATHER AT THE SURFACE. THE SYNOPTIC PATTERN AT THE SURFACE CONTINUES TO BE STRAIGHT FORWARD IN THAT FRESH TO STRONG EASTERLY TRADES WILL PERSIST DUE TO A STRONG HIGH PRESSURE RIDGE POSITIONED OVER THE SW NORTH ATLC. STRONGER WINDS TO MODERATE GALE FORCE ARE EXPECTED IN THE VICINITY OF THE COLOMBIA COAST FROM 11N TO 13N BETWEEN 73W TO 77W. OTHERWISE THIS EVENING...A FEW SHALLOW ISOLATED SHOWERS ARE OCCURRING ACROSS THE BASIN WITHIN 30 NM OF A LINE FROM 18N78W TO 16N83W. ATLANTIC OCEAN... AN UPPER LEVEL SHORTWAVE TROUGH AXIS EXTENDS FROM 31N81W TO 23N76W OVER THE CENTRAL BAHAMAS AND INTO THE WESTERN CARIBBEAN SEA. THIS TROUGHING IS PROVIDING DIFFLUENT FLOW ALOFT N OF 26N E OF 65W OVER THE SW NORTH ATLC WATERS CONTINUING TO GENERATE SCATTERED SHOWERS AND ISOLATED TSTMS N OF 27N BETWEEN 75W TO THE FLORIDA COAST THIS EVENING. WEAK UPPER LEVEL RIDGING COVERS THE REMAINDER OF THE WESTERN ATLC WITH MOSTLY WEST-NORTHWESTERLY FLOW ALOFT. TO THE NE OF THIS RIDGE...AN UPPER LEVEL TROUGH IS NOTED ON WATER VAPOR IMAGERY OVER THE CENTRAL NORTH ATLC WITH AXIS FROM 37N42W TO 30N56W. THIS TROUGHING SUPPORTS A COLD FRONT ANALYZED INTO THE REGION NEAR 32N42W THAT CONTINUES SW TO 26N57W THEN BECOMES STATIONARY TO 24N68W. ISOLATED SHOWERS ARE OCCURRING WITHIN 90 NM EITHER SIDE OF THE FRONT. OTHERWISE THE REMAINDER OF THE EASTERN ATLC IS UNDER THE INFLUENCE OF SURFACE RIDGING ANCHORED BY A WEAKENING 1025 MB HIGH CENTERED NEAR 29N38W. A WEAK SURFACE TROUGH IS EMBEDDED WITHIN THE EASTERN PERIPHERY OF THE RIDGE AND IS ANALYZED FROM 30N27W TO 26N28W. FOR ADDITIONAL INFORMATION PLEASE VISIT HTTP://WWW.HURRICANES.GOV/MARINE $$ HUFFMAN