000 AXNT20 KNHC 120002 TWDAT TROPICAL WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 805 PM EDT SAT APR 11 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 2315 UTC. ...ITCZ/MONSOON TROUGH... THE MONSOON TROUGH EXTENDS FROM THE AFRICAN COAST NEAR 08N13W TO 01N23W WHERE IT TRANSITIONS TO THE ITCZ. THE ITCZ THEN CONTINUES ACROSS THE EQUATOR NEAR 28N AND TO THE COAST OF S AMERICA NEAR 03S39W. ISOLATED MODERATE CONVECTION IS FROM 02S TO 02N BETWEEN 09W AND 42W. ...DISCUSSION... GULF OF MEXICO... WESTERLY FLOW ALOFT CONTINUES TO PREVAIL OVER MUCH OF THE GULF BASIN THIS EVENING. TWO UPPER LEVEL DISTURBANCES ARE AFFECTING THE GULF...WITH THE WESTERNMOST LOCATED OVER THE EXTREME NW GULF NEAR 28N96W AND THE EASTERNMOST OVER N FLORIDA NEAR 28N83W. A TROUGH OVER THE OHIO VALLEY/NEW ENGLAND SUPPORTS A FRONTAL SYSTEM THAT ENTERS OUR AREA OF DISCUSSION AS A STATIONARY FRONT NEAR 31N83W AND OVER THE GULF WATERS NEAR APALACHICOLA AT 30N85W AND EXTENDS TO 28N90W TO THE S TEXAS COAST NEAR 27N97W. THE UPPER LEVEL DISTURBANCES ARE INTERACTING WITH THIS FRONT TO PRODUCE CLUSTERS OF MODERATE CONVECTION FROM 26N TO 31N BETWEEN 88W AND 96W...AND ALSO OVER THE CENTRAL AND NORTHERN FL PENINSULA. WEAKENING MODERATE CONVECTION IS ALSO LOCATED OVER THE NE GULF FROM 28N TO 30N BETWEEN 83W AND 86W ASSOCIATED WITH A PRE-FRONTAL TROUGH THAT AS OF 1800 UTC EXTENDED FROM 30N86W TO 28N88W. ELSEWHERE...A SURFACE TROUGH VOID OF CONVECTION EXTENDS OVER THE SW BASIN FROM 23N94W TO 18N95W. SOUTHEASTERLY SURFACE WINDS OF 10 TO 15 KT DOMINATE THE SOUTHERN GULF AROUND ATLC HIGH PRESSURE. WINDS BECOME VARIABLE NEAR THE STATIONARY FRONT...GUSTY IN THE VICINITY OF THUNDERSTORMS. THE STATIONARY FRONT IS FORECAST TO REMAIN IN TACT AS AT MEANDERS NORTHWARD OVER THE NORTHERN PORTION OF THE BASIN TONIGHT...DISSIPATING BY SUNDAY NIGHT. CONVECTION WILL CONTINUE TONIGHT AND INTO THE DAY SUNDAY ACROSS THE N GULF. ALTHOUGH THE FRONT WILL DISSIPATE LATER ON SUNDAY...DEEP MOISTURE IN THE PRESENCE OF ADDITIONAL UPPER LEVEL DISTURBANCES WILL CONTINUE TO SUPPORT CONVECTION MAINLY OVER THE NORTHERN HALF OF THE BASIN THROUGH MONDAY. CARIBBEAN SEA... TRADE WIND FLOW OF 15 TO 20 KT DOMINATES MUCH OF THE CARIBBEAN THIS EVENING WITH WINDS OF 25 KT WITHIN 150 NM N OF THE COAST OF COLOMBIA AND WESTERN VENEZUELA. SOUTHWESTERLY FLOW ALOFT COVERS THE BASIN...WITH DRY AIR IN THE UPPER LEVELS OVER THE WESTERN CARIBBEAN...AND INCREASING MIDDLE TO UPPER LEVEL MOISTURE OVER THE CENTRAL AND EASTERN CARIBBEAN. MOSTLY DAYTIME DRIVEN LANDMASS THUNDERSTORMS ARE OVER CUBA..JAMAICA...AND THE YUCATAN. CONVECTION OVER COLOMBIA AND PANAMA MAY ENTER THE EXTREME SOUTHERN PORTIONS OF THE CARIBBEAN TONIGHT. GENERALLY FAIR WEATHER WITH THE EXCEPTION OF TRADE WIND SHOWERS ARE EXPECTED ON SUNDAY. ...HISPANIOLA... ISOLATED THUNDERSTORM ACTIVITY FROM THIS AFTERNOON IS DISSIPATING OVER THE CENTRAL PORTION OF THE ISLAND THIS EVENING. MAINLY FAIR CONDITIONS ARE EXPECTED OVERNIGHT. ADDITIONAL ISOLATED THUNDERSTORMS ARE POSSIBLE DURING THE AFTERNOON AND EVENING HOURS ON SUNDAY. ATLANTIC OCEAN... AN UPPER LEVEL TROUGH OVER THE OHIO VALLEY AND NEW ENGLAND SUPPORTS A COLD FRONT OFFSHORE OF SOUTH CAROLINA TO THE GEORGIA COAST. THE COMBINATION OF PRE-FRONTAL CONVERGENCE AND AN UPPER LEVEL DISTURBANCE MOVING EASTWARD ACROSS N FL IS PRODUCING SCATTERED MODERATE CONVECTION WITH THUNDERSTORMS FROM 28N TO 31N BETWEEN 76W AND INLAND OVER THE FLORIDA PENINSULA. FARTHER EAST...A PAIR OF SURFACE TROUGHS ARE MOVING WESTWARD AROUND THE PERIPHERY OF ATLC HIGH PRESSURE. THE WESTERNMOST TROUGH IS LOCATED FROM 26N63W TO 21N64W. THIS TROUGH IS INTERACTING WITH AN UPPER LOW NEAR 28N59W TO PRODUCE SHOWERS AND ISOLATED MODERATE CONVECTION MAINLY WITHIN 150 NM EAST OF THE TROUGH AXIS. THE EASTERNMOST TROUGH EXTENDS FROM 25N54W TO 21N55W AND HAS SHOWERS WITHIN 75 NM OF EITHER SIDE OF THE TROUGH AXIS. THE REMAINDER OF THE CENTRAL AND EASTERN SUBTROPICAL ATLC IS DOMINATED BY RIDGING WITH A 1026 MB HIGH CENTER NEAR 29N48W. OVER THE NEXT COUPLE OF DAYS A STATIONARY FRONT WILL EXPAND FROM THE FL COAST AND INTO THE WESTERN ATLC TO NEAR 60W BY MONDAY MORNING. THIS BOUNDARY WILL BE THE FOCUS FOR CONVECTION AS IT PROPAGATES EASTWARD OVER THE BASIN ON SUNDAY. FOR ADDITIONAL INFORMATION PLEASE VISIT HTTP://WWW.HURRICANES.GOV/MARINE $$ LATTO