000 AXNT20 KNHC 190546 TWDAT TROPICAL WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 205 AM EDT FRI APR 19 2013 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 0000 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 0515 UTC. ...ITCZ/MONSOON TROUGH... THE MONSOON TROUGH EXTENDS FROM THE AFRICAN COAST NEAR 10N15W TO 06N20W. THE INTERTROPICAL CONVERGENCE ZONE AXIS EXTENDS FROM 06N20W TO 05N30W TO THE EQUATOR NEAR 45W. SCATTERED MODERATE CONVECTION IS FROM 03N-05N BETWEEN 06W-10W. ISOLATED MODERATE CONVECTION IS WITHIN 60 NM EITHER SIDE OF A LINE FROM 04N31W TO 04N45W. ...DISCUSSION... GULF OF MEXICO... A VIGOROUS MIDDLE TO UPPER LEVEL TROUGH IS NOTED ON WATER VAPOR IMAGERY OVER THE UPPER MISSISSIPPI RIVER VALLEY AND CENTRAL PLAINS THAT SUPPORTS A COLD FRONT ANALYZED INTO THE NW GULF NEAR 30N93W SW TO 27N95W TO THE NE MEXICO COAST NEAR 25N98W. MOSAIC DOPPLER RADAR AND LIGHTNING DATA INDICATES WIDELY SCATTERED SHOWERS AND ISOLATED TSTMS ARE OCCURRING WITHIN 75 NM EITHER SIDE OF THE FRONT. EAST OF THE FRONT...SOUTH-SOUTHEASTERLY WINDS IN THE RANGE OF 10 TO 20 KT ARE FOUND ON THE SOUTHWESTERN PERIPHERY OF A SURFACE RIDGE ANCHORED OVER THE WESTERN NORTH ATLC. SKIES REMAIN GENERALLY CLEAR THIS EVENING AS WELL S OF 22N AND E OF 90W. NW OF THE COLD FRONT...STRONG NORTHERLY WINDS ARE OCCURRING AND FORECAST TO SPREAD SOUTH AND EAST THROUGH SATURDAY AS HIGH PRESSURE BUILDS IN FROM THE SOUTHERN PLAINS TO THE GULF COAST. CARIBBEAN SEA... CONDITIONS REMAIN TRANQUIL OVERALL THIS EVENING ACROSS MUCH OF THE CARIBBEAN BASIN AS DRY AIR AND SUBSIDENCE IS NOTED ON WATER VAPOR IMAGERY N OF 12N. SCATTERED TO BROKEN CONVECTIVE DEBRIS MIDDLE TO UPPER LEVEL CLOUDINESS CONTINUES TO STREAM NE ORIGINATING OVER THE SOUTH AMERICAN CONTINENT. ELSEWHERE...SKIES REMAIN CLEAR WITH ONLY A FEW ISOLATED SHOWERS NOTED ON SATELLITE IMAGERY OCCURRING ACROSS THE LESSER ANTILLES AND PORTIONS OF THE NE CARIBBEAN NORTHEAST OF A LINE FROM SAINT LUCIA TO WESTERN HISPANIOLA NEAR 18N74W. TRADES PERSIST AND WILL REMAIN QUITE BRISK THROUGH THE OVERNIGHT HOURS GENERALLY IN THE RANGE OF 15 TO 25 KT AS A RIDGE AND ASSOCIATED STRONG PRESSURE GRADIENT IS ANCHORED OVER THE SW NORTH ATLC. THIS OVERALL SYNOPTIC PATTERN IS EXPECTED TO PERSIST THROUGH THE WEEKEND WITH THE RIDGE TO THE NORTH WEAKENING GRADUALLY AND TRADES RELAXING BY EARLY SUNDAY AS A RESULT. ATLANTIC OCEAN... A DOME OF DRY AND SUBSIDENT MIDDLE TO UPPER LEVEL AIR IS NOTED ON WATER VAPOR IMAGERY OVER THE SW NORTH ATLC THAT IS PROVIDING FOR OVERALL CLEAR SKIES AND FAIR CONDITIONS THIS EVENING. LATEST SURFACE ANALYSIS SHOWS A RIDGE REMAINS ANCHORED OVER THE WESTERN NORTH ATLC BY A 1033 MB HIGH CENTERED SE OF NOVA SCOTIA NEAR 42N60W. THE ONLY FEATURE TO HIGHLIGHT IS A WEAK SURFACE TROUGH EMBEDDED WITHIN THE SOUTHERN PERIPHERY OF THE RIDGE ANALYZED FROM 25N57W TO 30N54W. POSSIBLE ISOLATED SHOWERS ARE NOTED IN THE VICINITY OF THE TROUGH AXIS FROM 24N-30N BETWEEN 53W-61W. FARTHER EAST...A MIDDLE TO UPPER LEVEL TROUGH AXIS EXTENDS FROM 37N45W TO 20N55W AND SUPPORTS A WEAK 1020 MB LOW CENTERED NEAR 36N39W AND AN ASSOCIATED COLD FRONT FROM 37N37W TO 32N38W TO 29N40W. ISOLATED SHOWERS AND TSTMS ARE OCCURRING WITHIN 180 NM EAST OF THE COLD FRONT AS THE LOW CONTINUES TO MOVE NE AND WELL NORTH OF THE DISCUSSION AREA IN 12 TO 24 HOURS. THE REMAINDER OF THE EASTERN ATLC IS UNDER THE INFLUENCE OF WEAK SURFACE RIDGING WITH NORTHEASTERLY TRADES S OF 30N IN THE RANGE OF 10 TO 20 KT. FOR ADDITIONAL INFORMATION PLEASE VISIT HTTP://WWW.HURRICANES.GOV/MARINE $$ HUFFMAN