000 AXNT20 KNHC 211817 CCA TWDAT TROPICAL WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 205 PM EDT MON APR 20 2015 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 1715 UTC. ...ITCZ/MONSOON TROUGH... THE MONSOON TROUGH EXTENDS ACROSS AFRICA INTO THE TROPICAL ATLANTIC NEAR 07N12W TO 04N15W WHERE THE ITCZ BEGINS AND CONTINUES S OF THE EQUATOR NEAR 26W TO THE N COAST OF BRAZIL NEAR 03S40W. SCATTERED MODERATE CONVECTION IS FROM 05S TO 05N BETWEEN 07W AND 45W. ...DISCUSSION... GULF OF MEXICO... ZONAL FLOW IN THE UPPER LEVELS RESIDES OVER THE GULF WITH AN MID TO UPPER LEVEL SHORTWAVE TROUGH OVER THE MID ATLC STATES. THIS TROUGH SUPPORTS A COLD FRONT THAT EXTENDS JUST OFFSHORE THE EASTERN SEABOARD...OVER CENTRAL FL...AND THE GULF NEAR THE TAMPA BAY AREA AT 28N83W TO 26N91W WHERE IT TRANSITIONS TO A STATIONARY FRONT TO THE NORTHERN MEXICO COAST NEAR 25N98W. A PRE- FRONTAL TROUGH EXTENDS ACROSS THE BAHAMAS AND S FLORIDA...AND EMERGES OVER THE GULF NEAR 26N82W TO 24N88W. SCATTERED SHOWERS AND THUNDERSTORMS ARE WITHIN 100 NM OF EITHER SIDE OF THE STATIONARY FRONT. SCATTERED MODERATE CONVECTION AND SHOWERS ARE BETWEEN THE COLD FRONT AND THE PRE-FRONTAL TROUGH...AND ALSO WITHIN 50 NM S OF THE TROUGH AXIS. ANOTHER SURFACE TROUGH IS LOCATED OVER THE SW GULF FROM 23N91W TO 19N92W. THIS TROUGH IS VOID OF ANY CONVECTION. SURFACE WINDS VARY FROM ONE QUADRANT OF THE GULF TO THE NEXT...WITH NE WINDS OF 10 TO 15 KT OVER THE NW BASIN...NW WINDS OF 10 TO 15 KT OVER THE NE AND SW BASIN...AND SOUTHERLY FLOW OVER THE SE BASIN S OF THE PRE-FRONTAL TROUGH. WINDS BECOME VARIABLE IN THE VICINITY OF THE FRONTAL BOUNDARY AND SURFACE TROUGHS. OVER THE NEXT 24 HOURS THE ENTIRE FRONTAL SYSTEM WILL BECOME STATIONARY. THE WESTERN PORTION OF THE STATIONARY FRONT WILL DISSIPATE. THIS WILL LEAVE THE STATIONARY FRONT DRAPED OVER THE EASTERN GULF AND CENTRAL/SOUTH FL PENINSULA ON WEDNESDAY. CONVECTION WILL CONTINUE TO BE LIKELY ESPECIALLY WITHIN 100 NM OF THE FRONTAL BOUNDARY TONIGHT THROUGH WEDNESDAY. CARIBBEAN SEA... GENERALLY DRY AND STABLE CONDITIONS IN THE MIDDLE TO UPPER LEVELS CONTINUE TO DOMINATE THE CARIBBEAN. THIS IS INHIBITING ANY DEEP CONVECTION ACROSS THE BASIN. AT THE SURFACE...ATLC RIDGING EXTENDS ACROSS THE NORTHERN CARIBBEAN WITH LOW PRESSURE OVER NORTHERN COLOMBIA. MODERATE TO FRESH TRADE WINDS BETWEEN THE RIDGE AND LOW COVER THE MAJORITY OF THE BASIN. OTHER THAN ISOLATED SHOWERS IN THE LOW LEVEL TRADE WIND MOISTURE...FAIR WEATHER IS BEING OBSERVED ACROSS THE BASIN. HISPANIOLA... MAINLY DAYTIME ISOLATED SHOWER AND THUNDERSTORM ACTIVITY IS EXPECTED OVER THE ISLAND OVER THE NEXT TWO DAYS. OTHERWISE...FAIR WEATHER IS EXPECTED. ATLANTIC OCEAN... A MID TO UPPER LEVEL TROUGH OVER THE MID ATLC STATES SUPPORTS A COLD FRONT THAT IS JUST OFFSHORE THE EASTERN SEABOARD AND EXTENDS INTO OUR AREA OF DISCUSSION NEAR 31N80W TO NORTH- CENTRAL FL NEAR 29N81W. A PRE-FRONTAL SURFACE TROUGH EXTENDS FROM 31N73W TO 27N77W TO THE MIAMI AREA NEAR 26N80W. SCATTERED MODERATE CONVECTION IS BETWEEN THE COLD FRONT AND SURFACE TROUGH...AND ALSO WITHIN 50 NM SE OF THE TROUGH AXIS. A NEARLY STATIONARY STORM SYSTEM OVER THE N CENTRAL ATLC SUPPORTS ANOTHER COLD FRONT THAT ENTERS OUR AREA NEAR 32N36W TO 27N46W WHERE IT TRANSITIONS TO A STATIONARY FRONT THAT EXTENDS TO 29N61W. SHOWERS ARE POSSIBLE WITHIN 75 NM OF EITHER SIDE OF THE FRONT. CENTRAL ATLC HIGH PRESSURE OF 1021 MB IS CENTERED JUST SOUTH OF THE FRONTAL SYSTEM NEAR 24N50W. GENERALLY FAIR WEATHER DOMINATES THE EASTERN ATLC FROM 05N TO 32N. OVER THE NEXT 24 HOURS THE COLD FRONT OFF THE SE US COAST WILL MOVE SE AND BY WEDNESDAY IS FORECAST TO EXTEND ACROSS THE NORTHERN BAHAMAS EASTWARD TO 70W. CONVECTION WITH THUNDERSTORMS WILL BE LIKELY TONIGHT THROUGH WEDNESDAY ALONG AND WITHIN 150 NM SE OF THE COLD FRONT. FOR ADDITIONAL INFORMATION PLEASE VISIT HTTP://WWW.HURRICANES.GOV/MARINE $$ LATTO