000 AXNT20 KNHC 151048 TWDAT TROPICAL WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 805 AM EDT SUN APR 15 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 0600 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 1015 UTC. ...ITCZ/MONSOON TROUGH... THE MONSOON TROUGH EXTENDS FROM THE AFRICAN COAST NEAR 07N11W TO 03N15W. THE INTERTROPICAL CONVERGENCE ZONE AXIS EXTENDS FROM 03N15W TO 01N20W TO 02N30W TO THE EQUATOR NEAR 40W THEN TO 01S45W. SCATTERED MODERATE AND ISOLATED STRONG CONVECTION IS FROM 03N-07N BETWEEN 11W-15W...AND FROM 03N-05N BETWEEN 25W-31W. SCATTERED MODERATE CONVECTION IS FROM THE EQUATOR TO 04N BETWEEN 31W-41W. ...DISCUSSION... GULF OF MEXICO... WATER VAPOR IMAGERY INDICATES MOSTLY DRY AIR AND SUBSIDENCE IS OVER THE GULF THIS MORNING AS AN UPPER LEVEL RIDGE WITH AXIS ALONG 90W CONTINUES TO EXTEND NORTHWARD OVER MUCH OF THE SE CONUS. THE OVERALL SUBSIDENT CONDITIONS FILTER DOWN TO THE LOWER LEVELS OF THE ATMOSPHERE AS A SURFACE RIDGE ANCHORED BY A 1028 MB HIGH REMAINS CENTERED OVER THE SW NORTH ATLC AND EXTENDS INFLUENCE WESTWARD OVER THE ENTIRE BASIN. STRONG E-SE WINDS ARE NOTED ACROSS THE BASIN AS MOIST LOW-LEVEL RETURN FLOW CONTINUES TO FUEL DEEP SURFACE LOW PRESSURE OVER THE CENTRAL PLAINS AND THE ASSOCIATED ONGOING CONVECTION THIS MORNING OVER THE CENTRAL AND SOUTHERN PLAINS. OVER THE NEXT 36 TO 48 HOURS...THE PRESSURE GRADIENT BETWEEN THE STRONG SURFACE LOW AND RIDGE ACROSS THE GULF WILL PERSIST UNTIL MONDAY WHEN THE GRADIENT WILL BEGIN TO RELAX GRADUALLY DUE TO A WEAK FRONTAL BOUNDARY EMERGING OFF THE TEXAS AND LOUISIANA COASTS. WEAK FRONTAL TROUGHING WILL REMAIN ACROSS THE NORTHERN GULF THROUGH TUESDAY INTO WEDNESDAY WITH WINDS GENERALLY IN THE RANGE OF 10 TO 15 KT. CARIBBEAN SEA... WEST-SOUTHWESTERLY UPPER LEVEL FLOW IS OVER THE CARIBBEAN THIS MORNING WITH UPPER LEVEL MOISTURE STREAMING NORTHEASTWARD OFF THE SOUTH AMERICAN CONTINENT DUE TO OVERNIGHT CONVECTION ACROSS PORTIONS OF NORTHERN COLOMBIA AND VENEZUELA. WATER VAPOR IMAGERY INDICATES MODERATELY DRY AIR OVER THE CARIBBEAN AND THIS IS RESULTING IN A LACK OF ANY SIGNIFICANT DEEP CONVECTION. OVER THE NE CARIBBEAN...A COLD FRONT EXTENDS FROM THE CENTRAL ATLC NEAR 20N60W TO 19N62W...THEN AS A SHEAR LINE TO 14N71W. LOW-LEVEL MOISTURE CONVERGENCE IN THE VICINITY OF THE FRONT AND SHEAR LINE IS GENERATING ISOLATED SHOWERS N OF 14N E OF 72W. MOISTURE LINGERS TO THE WEST FROM 15N-20N BETWEEN 74W-83W WITH ISOLATED SHOWERS POSSIBLE THIS MORNING. OTHERWISE...EAST-NORTHEAST TRADES ARE FORECAST TO PERSIST THROUGH SUNDAY...WITH STRONGER NE FLOW BLEEDING THROUGH THE WINDWARD AND MONA PASSAGES AS THE PRESSURE GRADIENT STRENGTHENS TO THE NORTH OVER THE SW NORTH ATLC BETWEEN 60W-80W. ATLANTIC OCEAN... AN UPPER LEVEL TROUGH IS OVER THE CENTRAL ATLC WITH AXIS EXTENDING FROM 35N55W TO 27N60W STRETCHING SW TO 24N68W. THIS TROUGH SUPPORTS A COLD FRONT ANALYZED INTO THE DISCUSSION AREA NEAR 32N48W TO 25N53W TO 20N60W AND INTO THE NE CARIBBEAN SEA. SCATTERED SHOWERS AND ISOLATED TSTMS ARE OCCURRING WITHIN 180 NM EITHER SIDE OF THE FRONT N OF 24N...AND ISOLATED SHOWERS WITHIN 120 NM EITHER SIDE OF THE FRONT S OF 24N. ELSEWHERE OVER THE REMAINDER OF THE SW NORTH ATLC...HIGH PRESSURE CONTINUES TO BUILD EASTWARD AS A 1028 MB HIGH CENTERED NEAR 32N71W IS FORECAST TO REMAIN IN CONTROL THROUGH WEDNESDAY. LOW-LEVEL MOISTURE IS ADVECTING AROUND THE SOUTHERN PERIPHERY OF THE RIDGE WITH POSSIBLE ISOLATED SHOWERS MOVING QUICKLY ACROSS THE BAHAMAS AND AREAS EAST OF 79W. FARTHER EAST ACROSS THE EASTERN ATLC...A RIDGE REMAINS THE DOMINATE INFLUENCE ANCHORED BY A STATIONARY 1032 MB HIGH CENTERED OVER THE AZORES NEAR 39N27W. FOR ADDITIONAL INFORMATION PLEASE VISIT HTTP://WWW.HURRICANES.GOV/MARINE $$ HUFFMAN 000 AXNT20 KNHC 151048 TWDAT TROPICAL WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 805 AM EDT SUN APR 15 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 0600 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 1015 UTC. ...ITCZ/MONSOON TROUGH... THE MONSOON TROUGH EXTENDS FROM THE AFRICAN COAST NEAR 07N11W TO 03N15W. THE INTERTROPICAL CONVERGENCE ZONE AXIS EXTENDS FROM 03N15W TO 01N20W TO 02N30W TO THE EQUATOR NEAR 40W THEN TO 01S45W. SCATTERED MODERATE AND ISOLATED STRONG CONVECTION IS FROM 03N-07N BETWEEN 11W-15W...AND FROM 03N-05N BETWEEN 25W-31W. SCATTERED MODERATE CONVECTION IS FROM THE EQUATOR TO 04N BETWEEN 31W-41W. ...DISCUSSION... GULF OF MEXICO... WATER VAPOR IMAGERY INDICATES MOSTLY DRY AIR AND SUBSIDENCE IS OVER THE GULF THIS MORNING AS AN UPPER LEVEL RIDGE WITH AXIS ALONG 90W CONTINUES TO EXTEND NORTHWARD OVER MUCH OF THE SE CONUS. THE OVERALL SUBSIDENT CONDITIONS FILTER DOWN TO THE LOWER LEVELS OF THE ATMOSPHERE AS A SURFACE RIDGE ANCHORED BY A 1028 MB HIGH REMAINS CENTERED OVER THE SW NORTH ATLC AND EXTENDS INFLUENCE WESTWARD OVER THE ENTIRE BASIN. STRONG E-SE WINDS ARE NOTED ACROSS THE BASIN AS MOIST LOW-LEVEL RETURN FLOW CONTINUES TO FUEL DEEP SURFACE LOW PRESSURE OVER THE CENTRAL PLAINS AND THE ASSOCIATED ONGOING CONVECTION THIS MORNING OVER THE CENTRAL AND SOUTHERN PLAINS. OVER THE NEXT 36 TO 48 HOURS...THE PRESSURE GRADIENT BETWEEN THE STRONG SURFACE LOW AND RIDGE ACROSS THE GULF WILL PERSIST UNTIL MONDAY WHEN THE GRADIENT WILL BEGIN TO RELAX GRADUALLY DUE TO A WEAK FRONTAL BOUNDARY EMERGING OFF THE TEXAS AND LOUISIANA COASTS. WEAK FRONTAL TROUGHING WILL REMAIN ACROSS THE NORTHERN GULF THROUGH TUESDAY INTO WEDNESDAY WITH WINDS GENERALLY IN THE RANGE OF 10 TO 15 KT. CARIBBEAN SEA... WEST-SOUTHWESTERLY UPPER LEVEL FLOW IS OVER THE CARIBBEAN THIS MORNING WITH UPPER LEVEL MOISTURE STREAMING NORTHEASTWARD OFF THE SOUTH AMERICAN CONTINENT DUE TO OVERNIGHT CONVECTION ACROSS PORTIONS OF NORTHERN COLOMBIA AND VENEZUELA. WATER VAPOR IMAGERY INDICATES MODERATELY DRY AIR OVER THE CARIBBEAN AND THIS IS RESULTING IN A LACK OF ANY SIGNIFICANT DEEP CONVECTION. OVER THE NE CARIBBEAN...A COLD FRONT EXTENDS FROM THE CENTRAL ATLC NEAR 20N60W TO 19N62W...THEN AS A SHEAR LINE TO 14N71W. LOW-LEVEL MOISTURE CONVERGENCE IN THE VICINITY OF THE FRONT AND SHEAR LINE IS GENERATING ISOLATED SHOWERS N OF 14N E OF 72W. MOISTURE LINGERS TO THE WEST FROM 15N-20N BETWEEN 74W-83W WITH ISOLATED SHOWERS POSSIBLE THIS MORNING. OTHERWISE...EAST-NORTHEAST TRADES ARE FORECAST TO PERSIST THROUGH SUNDAY...WITH STRONGER NE FLOW BLEEDING THROUGH THE WINDWARD AND MONA PASSAGES AS THE PRESSURE GRADIENT STRENGTHENS TO THE NORTH OVER THE SW NORTH ATLC BETWEEN 60W-80W. ATLANTIC OCEAN... AN UPPER LEVEL TROUGH IS OVER THE CENTRAL ATLC WITH AXIS EXTENDING FROM 35N55W TO 27N60W STRETCHING SW TO 24N68W. THIS TROUGH SUPPORTS A COLD FRONT ANALYZED INTO THE DISCUSSION AREA NEAR 32N48W TO 25N53W TO 20N60W AND INTO THE NE CARIBBEAN SEA. SCATTERED SHOWERS AND ISOLATED TSTMS ARE OCCURRING WITHIN 180 NM EITHER SIDE OF THE FRONT N OF 24N...AND ISOLATED SHOWERS WITHIN 120 NM EITHER SIDE OF THE FRONT S OF 24N. ELSEWHERE OVER THE REMAINDER OF THE SW NORTH ATLC...HIGH PRESSURE CONTINUES TO BUILD EASTWARD AS A 1028 MB HIGH CENTERED NEAR 32N71W IS FORECAST TO REMAIN IN CONTROL THROUGH WEDNESDAY. LOW-LEVEL MOISTURE IS ADVECTING AROUND THE SOUTHERN PERIPHERY OF THE RIDGE WITH POSSIBLE ISOLATED SHOWERS MOVING QUICKLY ACROSS THE BAHAMAS AND AREAS EAST OF 79W. FARTHER EAST ACROSS THE EASTERN ATLC...A RIDGE REMAINS THE DOMINATE INFLUENCE ANCHORED BY A STATIONARY 1032 MB HIGH CENTERED OVER THE AZORES NEAR 39N27W. FOR ADDITIONAL INFORMATION PLEASE VISIT HTTP://WWW.HURRICANES.GOV/MARINE $$ HUFFMAN