000 AXNT20 KNHC 052357 TWDAT TROPICAL WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 705 PM EST MON MAR 05 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 10N14W TO 08N18W TO 04N21W. THE INTERTROPICAL CONVERGENCE ZONE AXIS EXTENDS FROM 04N21W TO THE EQUATOR NEAR 26W. SCATTERED MODERATE CONVECTION IS WITHIN 90 NM EITHER SIDE OF A LINE FROM THE EQUATOR AND 06W TO 04N12W AND FROM 01N-04 BETWEEN 20W-24W. ...DISCUSSION... GULF OF MEXICO... WATER VAPOR IMAGERY INDICATES THAT DRY AIR AND STRONG SUBSIDENCE PREVAILS ALOFT OVER MUCH OF THE GULF THIS EVENING AS WESTERLY FLOW DOMINATES. AT THE SURFACE...A 1031 MB HIGH IS CENTERED NEAR 29N92W AND IS PROVIDING CLEAR SKIES AND FAIR CONDITIONS THIS EVENING. STRONG NORTHEAST WINDS IN THE RANGE OF 20 TO 25 KT ARE OBSERVED ON THE SOUTHEAST PERIPHERY OF THIS RIDGE OVER THE SE GULF WATERS. THE RIDGE IS FORECAST TO DRIFT NE AND MERGE WITH ANOTHER SURFACE HIGH CURRENTLY OVER THE OHIO RIVER VALLEY MOVING E-SE TO THE CAROLINAS BY TUESDAY. THE RIDGE...REMAINING RELATIVELY STRONG...WILL MAINTAIN A TIGHT PRESSURE GRADIENT AND RESULT IN FRESH TO STRONG E-SE TRADES OVER MUCH OF THE GULF THROUGH THURSDAY. CARIBBEAN SEA... WEAK UPPER LEVEL TROUGHING IS OVER THE WESTERN CARIBBEAN THIS EVENING AND SUPPORTS A REMNANT FRONTAL BOUNDARY ANALYZED AS A SHEAR LINE FROM EASTERN CUBA NEAR 21N78W TO 16N87W IN THE GULF OF HONDURAS. THE FRONT HAS LOST MUCH OF ITS CONVECTIVE PUNCH THE LAST 24 HOURS...HOWEVER...A FEW ISOLATED SHOWERS AND TSTMS ARE OCCURRING FROM 16N-18N BETWEEN 84W-88W. THE OTHER IMPACT WHICH IS FOUND ACROSS MUCH OF THE BASIN DUE TO A STRONG PRESSURE GRADIENT SET UP BETWEEN HIGH PRESSURE OVER THE SW NORTH ATLC AND LOWER PRESSURE OVER SOUTH AMERICA IS INCREASED E TO NE WINDS IN THE RANGE OF 20 TO 30 KT. WINDS ARE FORECAST TO REACH GALE FORCE NEAR THE COAST OF COLOMBIA LATER TONIGHT AND PERSIST THROUGH THURSDAY. ELSEWHERE OVER EASTERN PORTIONS OF THE CARIBBEAN... FAIR WEATHER CONDITIONS AND MOSTLY CLEAR SKIES ARE EXPECTED THROUGH THE OVERNIGHT HOURS INTO TUESDAY. ATLANTIC OCEAN... AN UPPER LEVEL TROUGH IS NOTED ON WATER VAPOR IMAGERY WITH AXIS EXTENDING ALONG THE EASTERN U.S. SEABOARD FROM OVER THE MID-ATLC STATES TO OFF THE COAST OF NORTHERN FLORIDA. THE TROUGHING SUPPORTS A COLD FRONT ANALYZED INTO THE DISCUSSION AREA NEAR 32N62W AND EXTENDS SW TO THE SE BAHAMAS NEAR 23N74W TO EASTERN CUBA AND INTO THE NW CARIBBEAN SEA. ISOLATED SHOWERS ARE OCCURRING WITHIN 150 NM WEST OF THE FRONT. WEST OF THE FRONT...RIDGING EXTENDS FROM THE EASTERN GULF OF MEXICO ACROSS CENTRAL FLORIDA TO 30N69W AND IS PROVIDING CLEAR SKIES THIS EVENING. A SECONDARY COLD FRONT IS HOWEVER EMERGING OFF THE EAST COAST OF THE U.S. AND USHERING IN ANOTHER BATCH OF STRONG NORTHWESTERLY WINDS REMAINING MOSTLY N OF 30N. WINDS OVER THE SW NORTH ATLC WILL INCREASE OVER THE NEXT 24 TO 36 HOURS AS HIGH PRESSURE MOVES ACROSS THE SE CONUS BY TUESDAY. ELSEWHERE ACROSS THE REMAINDER OF THE CENTRAL AND EASTERN ATLC...A SURFACE RIDGE ANCHORED BY A 1031 MB HIGH CENTERED NEAR 34N44W IS PROVIDING GENERALLY FAIR CONDITIONS AND NE TRADES IN THE RANGE OF 15 TO 20 KT E OF 35W. FOR ADDITIONAL INFORMATION PLEASE VISIT HTTP://WWW.HURRICANES.GOV/MARINE $$ HUFFMAN