000 AXNT20 KNHC 222331 TWDAT TROPICAL WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 805 PM EDT THU MAR 22 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 ACROSS W AFRICA TO THE COAST OF LIBERIA NEAR 6N10W TO 4N15W. THE ITCZ CONTINUES FROM 4N15W ALONG 3N25W 1N35W 2N41W TO THE BRAZIL COAST AT THE EQUATOR AND 47W. SCATTERED MODERATE/ISOLATED STRONG CONVECTION IS WITHIN 90 NM S OF THE AXIS BETWEEN THE AFRICAN COAST AND 15W. SIMILAR ACTIVITY IS WITHIN 90-120 NM EITHER SIDE OF THE AXIS BETWEEN 18W AND 29W. ...DISCUSSION... GULF OF MEXICO... A STATIONARY FRONT CONTINUES TO SIT OVER THE CENTRAL/WRN GULF OF MEXICO THIS AFTERNOON EXTENDING FROM THE MISSISSIPPI/ALABAMA BORDER AT 30N89W TO A 1013 MB LOW NEAR 23N94W. A SURFACE TROUGH EXTENDS S FROM THE LOW CENTER TO THE COAST OF MEXICO NEAR 19N92W. A LINE OF SLOW MOVING HEAVY SHOWERS/THUNDERSTORMS IS ALONG THE FRONT N OF 29N EXTENDING NORTHWARD INTO THE COASTS OF LOUISIANA...MISSISSIPPI AND ALABAMA. LIGHTNING DATA INDICATED NUMEROUS STRIKES WITHIN THE PAST HOUR WITH THESE STORMS. THE STORMS WERE CAPABLE OF PRODUCING VERY HEAVY RAINFALL WITH STORM TOTAL AMOUNTS OF 8 TO 12 INCHES FORECAST FOR THE AREA. AN ISOLATED CLUSTER OF STRONG THUNDERSTORMS WERE ALSO NOTED WITHIN 45 NM OF 26.5N88W WITH NUMEROUS LIGHTNING STRIKES AT PRESENT. THE AREA OF LOW CLOUDS ASSOCIATED WITH THE REMAINDER OF THE FRONT S OF 25N HAVE GRADUALLY DISSIPATED OVER THE PAST HOUR. THE FRONT IS SUPPORTED BY A LARGE NEARLY STATIONARY CUT-OFF UPPER LEVEL LOW OVER THE OKLAHOMA-KANSAS BORDER NEAR 37N98W. THE ASSOCIATED TRAILING TROUGH WAS GRADUALLY FILLING AND LIFTING NWD OVER THE NW GULF. A NARROW UPPER LEVEL RIDGE COVERS THE ERN GULF WITH AXIS ALONG 82W. EXCEPT FOR THE MOISTURE NEAR THE FRONT N OF 29N...THE REMAINDER OF THE BASIN IS COVERED BY DRY AIR ALOFT...WHICH IS HELPING MAINTAIN FAIR CONDITIONS AND CLEAR SKIES ACROSS THE ERN GULF AND NW GULF. MAINLY SE-S FLOW IS ACROSS THE BASIN BESIDES NEAR THE FRONT WITH SPEEDS OF 15-20 KTS E OF THE FRONT...AND 10-15 KTS W OF THE FRONT. THE FRONT IS EXPECTED TO LIFT NW AND DISSIPATE INTO A TROUGH AS SURFACE RIDGING BUILDS WESTWARD ACROSS THE BASIN. CARIBBEAN SEA... MUCH OF THE CARIBBEAN IS EXPERIENCING FAIR WEATHER TODAY UNDER THE INFLUENCE OF DRY AIR ALOFT IN MOSTLY SWLY FLOW ALOFT. HOWEVER...AN AREA OF MOISTURE THAT LIKELY ADVECTED FROM THE CENTRAL ATLC AFTER A FRONT DISSIPATED SEVERAL DAYS AGO IS IMPACTING THE EXTREME NE CARIBBEAN PRODUCING SHOWERS AND ISOLATED THUNDERSTORMS ACROSS THE VIRGIN ISLANDS...PUERTO RICO...AND HISPANIOLA N OF 18N BETWEEN 62-70W. SOME ISOLATED SHOWERS ARE ALSO NOTED OVER THE FAR SE CORNER N OF VENEZUELA AND THE ABC ISLANDS. THE REMAINDER OF THE BASIN HAS MOSTLY CLEAR SKIES. TRADEWIND FLOW OF 15-20 KTS IS ACROSS THE MAJORITY OF THE BASIN WITH SOME STRONGER WINDS NEAR THE COAST OF COLOMBIA. EXPECT LITTLE CHANGE OVER THE NEXT 24 HOURS WITH CONTINUED SHOWER ACTIVITY OVER THE NE ISLANDS AND N OF VENEZUELA. ATLANTIC OCEAN... SURFACE RIDGING COVERS THE W ATLC ANCHORED BY A 1030 MB HIGH NEAR 34N68W PROVIDING MOSTLY FAIR WEATHER ACROSS THIS AREA. AN AREA OF MOISTURE HAS ADVECTED AROUND THE SRN PORTION OF THE RIDGE LIKELY ORIGINATED FROM A DISSIPATED FRONTAL BOUNDARY AND IS NOW IMPACTING THE NE CARIBBEAN ISLANDS FROM 18N-21N BETWEEN 58W-73W. SCATTEROMETER DATA FROM A 1534 UTC OSCAT PASS SUPPORTED THE PRESENCE OF A SHEAR LINE WHICH NOW EXTENDS FROM 20N50W TO 19N60W TO JUST NE OF HISPANIOLA. THE HIGH PRES AND ASSOCIATED RIDGE IS SUPPORTED BY A HIGH AMPLITUDE UPPER LEVEL RIDGE EXTENDING OFF THE ERN CONUS TO AN ANTICYCLONE NEAR 35N58W. SHARP UPPER LEVEL TROUGH EXTENDS FROM 32N22W THROUGH 25N35W THEN TRANSITIONS TO A SHEAR AXIS THROUGH 26N45W TO AN UPPER LEVEL CYCLONE NEAR 26N64W. A REINFORCING UPPER LEVEL TROUGH GRAZES THE DISCUSSION AREA ALONG 30N BETWEEN 30W AND 40W. THE UPPER TROUGH SUPPORTS A COLD FRONT BRUSHING THE DISCUSSION AREA NEAR 31N35W. THE FAR ERN ATLC IS COVERED BY AN UPPER LEVEL RIDGE ALONG 9W. MAINLY WLY FLOW ALOFT COVERS THE TROPICAL ATLC. FOR ADDITIONAL INFORMATION PLEASE VISIT HTTP://WWW.HURRICANES.GOV/MARINE $$ COBB