000 AXNT20 KNHC 051752 TWDAT TROPICAL WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 105 PM EST SAT MAR 05 2011 TROPICAL WEATHER DISCUSSION FOR NORTH AMERICA...CENTRAL AMERICA...GULF OF MEXICO...CARIBBEAN SEA...NORTHERN SECTION OF SOUTH AMERICA...AND ATLANTIC OCEAN TO THE AFRICAN COAST FROM THE EQUATOR TO 32N. THE FOLLOWING INFORMATION IS BASED ON SATELLITE IMAGERY...METEOROLOGICAL ANALYSIS...WEATHER OBSERVATIONS...AND RADAR. BASED ON 1200 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 1715 UTC. ...ITCZ... ITCZ AXIS IS ALONG 08N13W TO THE EQUATOR NEAR 22W THEN INTO NE BRAZIL NEAR 04S39W. ISOLATED MODERATE CONVECTION IS FROM THE EQUATOR TO 03N BETWEEN 19W-23W. A SURFACE TROUGH IS ANALYZED ON THE WESTERN EXTENT OF THE AXIS ALONG COASTAL NE BRAZIL FROM 03S48W TO 05N51W. ISOLATED MODERATE CONVECTION IS OCCURRING WITHIN 120 NM EITHER SIDE OF THE SURFACE TROUGH. ...DISCUSSION... GULF OF MEXICO... WATER VAPOR IMAGERY INDICATES A SHARP UPPER LEVEL TROUGH IS LOCATED OVER THE CENTRAL U.S. AND CONTINUES TO MOVE QUICKLY ACROSS MUCH OF THE STATE OF TEXAS THIS AFTERNOON. THIS UPPER LEVEL TROUGHING SUPPORTS A COLD FRONT THAT AT 05/1500 UTC HAS EMERGED OFF THE TEXAS GULF COAST AND EXTENDS FROM SABINE LAKE AND PASS NEAR PORT ARTHUR TEXAS SW TO SOUTH OF CORPUS CHRISTI NEAR BAFFIN BAY. MOSAIC DOPPLER RADAR AND LIGHTNING DATA INDICATE NUMEROUS SHOWERS AND SCATTERED TO BROKEN AREAS OF TSTMS WITHIN 30 NM OF THE COLD FRONT. A PRE-FRONTAL LINE OF SCATTERED TSTMS IS ALSO WITHIN 30 NM OF A LINE FROM 28N93W TO THE LOUISIANA COAST NEAR VERMILION BAY. WEST OF THE FRONT...STRONG NORTHERLY WINDS TO GALE FORCE ARE EXPECTED BY SATURDAY EVENING. AS THE FRONT SWEEPS QUICKLY EASTWARD AND LOCATES IN THE W ATLC BY EARLY MONDAY...HIGH PRESSURE WILL BUILD IN ACROSS MUCH OF THE GULF WITH RIDGE AXIS ALONG 90W. CARIBBEAN SEA... CONFLUENT FLOW ALOFT IS LOCATED OVER MUCH OF THE CARIBBEAN THIS AFTERNOON WHICH IS PROVIDING FOR GENERAL SUBSIDENCE AND MOSTLY DRY AIR IN THE UPPER LEVELS OF THE ATMOSPHERE. AT THE SURFACE... EASTERLY TRADES IN THE RANGE OF 15 TO 20 KT CONTINUE DUE TO A MARGINALLY STRONG PRESSURE GRADIENT ACROSS THE REGION...WITH HIGHER VALUES UP TO 25 KT WITHIN 120 NM OF THE COAST OF COLOMBIA. AN EARLIER 05/1104 WINDSAT PASS CAPTURED THESE STRONGER WINDS AND THEY ARE EXPECTED TO PERSIST THROUGH THE REMAINDER OF THE WEEKEND. ELSEWHERE...THE REMAINDER OF THE CARIBBEAN REMAINS TRANQUIL WITH ISOLATED SHOWER ACTIVITY FOUND MOSTLY OVER SE PORTIONS S OF 16N E OF 71W. ATLANTIC OCEAN... A STRONG 1044 MB HIGH IS POSITIONED OFF THE COAST OF NOVA SCOTIA NEAR 45N58W AND EXTENDS A RIDGE AXIS SW FROM THE HIGH THROUGH 32N72W TO THE SOUTHERN FLORIDA PENINSULA. ON THE SOUTHEASTERN PERIPHERY OF THIS RIDGE...STRONG NE TO E WINDS IN THE RANGE OF 20 TO 30 KT WERE NOTED ON EARLIER MORNING WINDSAT AND ASCAT PASSES BETWEEN 05/1200 UTC AND 05/1430 UTC. THIS WIND FIELD LOCATES NW OF A STATIONARY FRONTAL BOUNDARY ANALYZED INTO THE DISCUSSION AREA NEAR 32N54W TO 31N56W BECOMING A SURFACE TROUGH ALONG 28N60W TO 25N69W TO THE WINDWARD PASSAGE NEAR 20N74W. THIS BOUNDARY IS LARGELY SUPPORTED ALOFT BY AN UPPER LEVEL TROUGH WITH AXIS ALONG 62W. LOW-LEVEL CONVERGENCE NEAR THE STATIONARY FRONT AND SURFACE TROUGH...ALONG WITH MIDDLE TO UPPER LEVEL LIFT ASSOCIATED WITH THE UPPER LEVEL FEATURE IS GENERATING AN AREA OF SCATTERED SHOWERS AND ISOLATED TSTMS COVERING THE AREA N OF 24N BETWEEN 52W-60W. FARTHER EAST...A PAIR OF WEAK SURFACE TROUGHS ARE IMPACTING THE EASTERN ATLC. ONE SURFACE TROUGH IS ANALYZED FROM 24N32W TO 30N43W AND IS GENERATING ISOLATED SHOWERS WITHIN 90 NM EAST OF THE BOUNDARY. THE SECOND SURFACE TROUGH IS ASSOCIATED WITH A DEEP LAYER LOW CENTERED OFF THE IBERIAN PENINSULA NEAR 38N15W AND IS ANALYZED ACROSS THE CANARY ISLANDS FROM 31N13W TO 26N21W. ISOLATED SHOWERS ARE WITHIN 60 NM EITHER SIDE OF THE BOUNDARY. FOR ADDITIONAL INFORMATION PLEASE VISIT HTTP://WWW.HURRICANES.GOV/MARINE $$ HUFFMAN