000 AXNT20 KNHC 170005 TWDAT TROPICAL WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 805 PM EDT SAT APR 16 2016 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 2345 UTC. ...ITCZ/MONSOON TROUGH... THE MONSOON TROUGH EXTENDS ACROSS LIBERIA AFRICA INTO THE E TROPICAL ATLC NEAR 05N09W AND THEN CONTINUES TO 04N13W...WHERE THE ITCZ BEGINS AND THEN EXTENDS ALONG 02N23W TO 02S35W TO THE COAST OF NORTHERN BRAZIL NEAR 01S45W. ...DISCUSSION... GULF OF MEXICO... A MIDDLE TO UPPER LEVEL TROUGH ASSOCIATED WITH A LOW OVER THE NW ATLC EXTENDS SW ACROSS THE FLORIDA PENINSULA WITH BASE REACHING THE GULF E OF 84W. A COLD FRONT SUPPORTED BY BOTH THE LOW AND TROUGH ALOFT EXTENDS ACROSS SW N ATLC WATERS...THE NORTHERN BAHAMAS...SOUTHERN FLORIDA TO 25N81W THEN ACROSS THE CENTRAL GULF TO 26N90W TO GALVESTON TEXAS OFFSHORE WATERS NEAR 28N95W. FRESH TO STRONG WINDS PREVAILS N OF THE FRONT BEING SUPPORTED BY A STRONG PRES GRADIENT BETWEEN A RIDGE THAT COVERS THE EASTERN CONUS AND LOWER PRES ASSOCIATED WITH THE FRONTAL BOUNDARY. SCAT DATA INDICATE LIGHT SE FLOW DOMINATE ELSEWHERE. SCATTERED MODERATE/ISOLATED STRONG CONVECTION AND TSTMS ARE WITHIN 120-170 NM S OF THE FRONT AND WITHIN 120 NM N OF THE FRONT E OF 91W. MOISTURE BEING ADVECTED FROM THE EPAC WATERS BY AN ATMOSPHERIC RIVER CONVERGING WITH MOISTURE INFLOW FROM THE CARIBBEAN ALONG WITH DIFFLUENCE ALOFT SUPPORT THIS CONVECTION. OTHERWISE...THE GOES IFR INDICATE MODERATE TO HIGH PROBABILITIES OF DENSE FOG S OF 27N W OF 88W. VESSELS AND BOATS IN THIS REGION SHOULD EXERCISE CAUTION AS VISIBILITY MAY BE LESS THAN 3 MILES. CARIBBEAN SEA... ZONAL FLOW PREVAILS ALOFT ACROSS THE BASIN WITH WATER VAPOR IMAGERY INDICATING DRY AIR SUBSIDENCE TO SUPPORT GENERALLY FAIR WEATHER. EXCEPT WITHIN 90 NM OFF THE COAST OF COLOMBIA WHERE LOCAL GEOGRAPHY SUPPORT FRESH WINDS...A RELAXED PRES GRADIENT CONTINUE TO SUSTAIN LIGHT TO MODERATE TRADES. SHALLOW MOISTURE EMBEDDED IN THE TRADE WIND FLOW IS LIKELY TO SUPPORT ISOLATED SHOWERS IN THE GREATER ANTILLES...JAMAICA AND THE SE CARIBBEAN. A SURFACE TROUGH WILL ENTER THE NE BASIN SUN BRINGING SHOWERS TO THE LEEWARD ISLANDS. THESE SHOWERS WILL AMPLIFY AND WILL AFFECT PUERTO RICO AND HISPANIOLA LATE SUN AND MON AS THE SURFACE TROUGH MOVES W AND MIDDLE TO UPPER LEVEL TROUGHING OVER THE ATLC DEEPENS ACROSS THE CENTRAL AND EASTERN CARIBBEAN. HISPANIOLA... ISOLATED SHOWERS ARE POSSIBLE TONIGHT ESPECIALLY IN THE MOUNTAINOUS TERRAIN DUE TO ATLC AND CARIBBEAN MOISTURE CONFLUENCE. SHOWERS WILL INCREASE SUN EVENING AS A COLD FRONT APPROACHES THE ISLAND FROM THE NW AND A SURFACE TROUGH TRAVERSE THE NE CARIBBEAN. ATLANTIC OCEAN... A COLD FRONT EXTENDS FROM 30N56W TO 24N70W TO THE SOUTHERN FLORIDA PENINSULA WITH ISOLATED SHOWERS WITHIN 90 NM OF THE BOUNDARY. E OF THE FRONT...A 1011 MB IS NEAR 26N52W. OTHERWISE...A COLD FRONT STARTS TO DEVELOP FROM 30N27W TO A 1012MB LOW NEAR 27N33W TO 26N45W. NO SHOWERS ASSOCIATED WITH THESE FEATURES. RIDGING DOMINATES ELSEWHERE. FOR ADDITIONAL INFORMATION PLEASE VISIT HTTP://WWW.HURRICANES.GOV/MARINE $$ RAMOS