000 AXNT20 KNHC 190555 TWDAT TROPICAL WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 105 AM EST SAT FEB 19 2011 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...METEOROLOGICAL ANALYSIS...WEATHER OBSERVATIONS...AND RADAR. BASED ON 0000 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 0515 UTC. ...ITCZ... THE ITCZ IS ANALYZED FROM SW AFRICA NEAR 8N12W 4N19W 1N25W 1N40W CROSSING THE EQUATOR NEAR 45W INTO SOUTH AMERICA. CLUSTERS OF SCATTERED MODERATE TO STRONG CONVECTION ARE FROM THE EQUATOR TO 6N E OF 14W TO ACROSS THE PRIME MERIDIAN. ...DISCUSSION... GULF OF MEXICO... BROAD UPPER RIDGE COVERS THE GULF WITH THE AXIS EXTENDING FROM THE W BAY OF CAMPECHE TO OVER THE SE CONUS NEAR E LOUISIANA WITH WATER VAPOR IMAGERY INDICATING STRONG SUBSIDENCE ACROSS THE ENTIRE AREA. A SURFACE RIDGE COVERS THE GULF INTO THE ATLC ANCHORED BY A 1024 MB HIGH S OF THE FLORIDA PANHANDLE NEAR 28N85W PROVIDING CLEAR SKIES OVER MOST OF THE GULF. THE EXCEPTION IS A FEW PATCHES OF LOW CLOUDS AND FOG OVER THE W GULF W OF 95W TO INLAND OVER TEXAS TO THE LOUISIANA BORDER AND MEXICO TO VERACRUZ AS RESULT OF THE RETURN FLOW AROUND THE SURFACE RIDGE. HIGH PRESSURE RIDGE WILL PREVAIL OVER THE N GULF THROUGH MON WITH THE NEXT FRONT MOVING INTO THE NW GULF ON TUE. CARIBBEAN SEA... AN UPPER RIDGE COVERS THE W CARIBBEAN WITH THE AXIS ALONG THE E COAST OF THE YUCATAN PENINSULA AND DOWNSTREAM UPPER TROUGH EXTENDING FROM THE CENTRAL ATLC THROUGH THE MONA PASSAGE TO THE GULF OF VENEZUELA. WATER VAPOR IMAGERY INDICATES STRONG SUBSIDENCE ALOFT COVERS THE CARIBBEAN GIVING THE AREA MOSTLY CLEAR SKIES TONIGHT. FRESH TO MODERATE SURFACE TRADE WINDS CONTINUE ACROSS THE CARIBBEAN USHERING SOME PATCHES OF ISOLATED SHOWERS MAINLY FROM 15N-19N BETWEEN 70W-80W. TRADE WINDS WILL INCREASE SAT NIGHT THROUGH MON AS THE SURFACE RIDGE N OF THE AREA DRIFTS SLOWLY SE AND STRENGTHENS THEN WILL BEGIN TO DIMINISH ON TUE AS THE RIDGE WEAKENS. ATLANTIC OCEAN... A UPPER LEVEL TROUGH DOMINATES THE FLOW W OF ABOUT 50W WITH THE AXIS EXTENDING THROUGH 32N50W 23N64W THROUGH THE MONA PASSAGE INTO THE CARIBBEAN. A SURFACE TROUGH IS JUST TO THE E OF THE UPPER TROUGH AXIS EXTENDING FROM FROM 23N62W TO THE VIRGIN ISLANDS NEAR 18N64W. WATER VAPOR IMAGERY INDICATES STRONG SUBSIDENCE ALOFT COVERS THE AREA S OF 28N W OF 60W THUS LIMITING SHOWER ACTIVITY ACROSS THE AREA. A SURFACE RIDGE COVERS THE W INTO THE CENTRAL ATLC ACROSS THE FLORIDA PENINSULA INTO THE GULF OF MEXICO ANCHORED BY A 1024 MB HIGH OFF THE FLORIDA COAST NEAR 29N77W AND A 1023 MB HIGH IN THE CENTRAL ATLC NEAR 29N56W. A LARGE UPPER LOW IS OVER THE NE ATLC WELL N OF THE AZORES SUPPORTING A DISSIPATING COLD FRONT THE ENTERS THE E ATLC NEAR 32N23W TO 27N30W BECOMING A SHEAR AXIS TO 21N56W. A WEAK SURFACE RIDGE IS E OF THE ABOVE FRONT ANCHORED BY A PAIR OF 1021 MB HIGHS...ONE N OF THE CANARY ISLANDS NEAR 30N15W AND A SECOND TO THE WSW NEAR 27N23W. BROAD UPPER RIDGE COVERS THE CENTRAL AND E ATLC WITH THE MEAN AXIS ALONG 35W. A JET STREAM WITH WINDS OF 90 TO 115 KT IS RIDING N ALONG THE W PORTION OF THE UPPER RIDGE WITHIN 200/300 NM OF LINE FROM 19N59W TO BEYOND 32N27W. AN UPPER LEVEL LOW IS UNDERCUTTING THE UPPER RIDGE LOCATED JUST S OF THE CAPE VERDE ISLANDS. HOWEVER... WATER VAPOR IMAGERY INDICATES STRONG SUBSIDENCE ALOFT FROM 10N-20N E OF 45W LIMITING ANY SHOWER ACTIVITY IN THE AREA. FOR ADDITIONAL INFORMATION PLEASE VISIT HTTP://WWW.HURRICANES.GOV/MARINE $$ PAW