000 AXNT20 KNHC 190002 TWDAT TROPICAL WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 805 PM EDT WED MAR 18 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 2345 UTC. ...ITCZ/MONSOON TROUGH... THE MONSOON TROUGH EXTENDS FROM THE AFRICAN COAST NEAR 07N12W TO 03N19W TO 01S22W. THE INTERTROPICAL CONVERGENCE ZONE AXIS EXTENDS FROM 01S22W TO 02S34W TO THE COAST OF NORTHERN BRAZIL AT THE EQUATOR ALONG 51W. SCATTERED SHOWERS ARE FROM 04S TO 15N BETWEEN E OF 23W AND FROM 05S TO 04N W OF 39W. ...DISCUSSION... GULF OF MEXICO... BROAD MIDDLE TO UPPER LEVEL TROUGHING OVER THE NW ATLC WITH BASE NEAR 30N AND A MID-LEVEL LOW CENTERED OFF THE COAST OF NOVA SCOTIA IS SUPPORTING A COLD FRONT ANALYZED FROM 31N62W W-SW TO THE FLORIDA PENINSULA NEAR 27N80W. FROM THERE THE FRONT TRANSITIONS TO A STATIONARY FRONT ACROSS CENTRAL FLORIDA NW TOWARDS NE GULF WATERS NEAR 28N86W TO SE LOUISIANA NEAR 29N90W. LOW LEVEL DRY AIR ADVECTION FROM THE SE CONUS MAINTAINS THE NE GULF FREE OF CONVECTION. LOW-LEVEL MOISTURE INFLOW FROM THE CARIBBEAN TO THE WESTERN GULF ALONG WITH A DIFFLUENT ENVIRONMENT ALOFT BEING GENERATED BY A SHORT-WAVE TROUGH OVER OKLAHOMA AND RIDGING ACROSS THE GULF SUPPORT SCATTERED TO ISOLATED SHOWERS N OF 26N W OF 87W. SEA FOG IS ALSO BEING REPORTED WITHIN 75 NM EITHER SIDE OF A SURFACE TROUGH FROM 28N91W TO 27N94W TO 26N96W. THE REMAINDER BASIN IS UNDER THE INFLUENCE OF A WEAK 1016 MB ANTICYCLONE CENTERED NEAR 25N88W EXPECTED TO DRIFT NE DURING THE NEXT 48 HOURS. THE STATIONARY WILL SLOWLY MOVE NE DURING THAT PERIOD WHERE IT WILL MERGE WITH THE NEXT COLD FRONT TO EMERGE FROM THE SE CONUS FRIDAY MORNING. CARIBBEAN SEA... WATER VAPOR IMAGERY CONTINUES TO SHOW RELATIVELY DRY AIR AND STABLE CONDITIONS ALOFT ASSOCIATED WITH A BROAD UPPER RIDGE COVERING THE GULF OF MEXICO AND THE CARIBBEAN. THIS IS SUPPORTING MAINLY FAIR WEATHER ACROSS THE REGION...EXCEPT FOR THE NE CARIBBEAN WHERE A SHALLOW MOIST AIRMASS IS ENHANCING SCATTERED TO ISOLATED SHOWERS. A TONGUE OF MOIST AIR IS NOTED IN SSMI TPW IMAGERY FROM HAITI TO JAMAICA TO COASTAL WATERS OF HONDURAS AND NICARAGUA...THUS ENHANCING SHOWERS FOR THIS REGION OF THE BASIN. IN TERMS OF WIND...WEAK HIGH PRESSURE TO THE NORTH ACROSS THE SW NORTH ATLC REGION ALLOW FOR TRADES OF 5 TO 10 KT...INCREASING TO 15 TO 20 KT OVER THE SW CARIBBEAN...THE HIGHEST ALONG THE COAST OF COLOMBIA. LITTLE CHANGE IS EXPECTED THROUGH SUNDAY. ...HISPANIOLA... CLEAR SKIES AND FAIR CONDITIONS PREVAIL OVER THE DOMINICAN REPUBLIC SUPPORTED BY DEEP LAYER DRY AIR. OVER THE WESTERN ISLAND...A LOW-LEVEL MOIST AIRMASS EXTENDING SW TO HONDURAS AND NICARAGUA COASTAL WATERS SUPPORT SCATTERED SHOWERS OVER HAITI. SIMILAR CONDITIONS ARE EXPECTED TO PREVAIL THROUGH SAT MORNING. ATLANTIC OCEAN... BROAD MIDDLE TO UPPER LEVEL TROUGHING OVER THE NW ATLC WITH BASE NEAR 30N AND A MID-LEVEL LOW CENTERED OFF THE COAST OF NOVA SCOTIA IS SUPPORTING A COLD FRONT ANALYZED FROM 31N62W W-SW TO THE FLORIDA PENINSULA NEAR 27N80W. ISOLATED SHOWERS ARE POSSIBLE WITHIN 75 NM EITHER SIDE OF THE FRONT E OF 62W. A PRE-FRONTAL SURFACE TROUGH IS ANALYZED SOUTHWARD FROM THE COLD FRONT ACROSS THE NW BAHAMAS TO WESTERN CUBA NEAR 22N80W. OTHERWISE...THE REMAINDER OF THE SW NORTH ATLC IS UNDER THE INFLUENCE OF WEAK RIDGING ANCHORED BY A 1018 MB HIGH CENTERED NEAR 23N60W.FARTHER EAST...A MIDDLE LEVEL SHORT-WAVE TROUGH SUPPORTS A DISSIPATING STATIONARY FRONT FROM 30N45W TO 25N51W TO 21N58W. ISOLATED SHOWERS ARE OCCURRING WITHIN 60 NM EITHER SIDE OF THE FRONT N OF 26N. FINALLY...THE REMAINDER OF THE EASTERN ATLC IS UNDER THE INFLUENCE OF A RIDGE ANCHORED BY A 1030 MB HIGH CENTERED S OF THE AZORES NEAR 36N27W. A NEW COLD FRONT ENTERS THE SW N ATLC WATERS FRIDAY MORNING. FOR ADDITIONAL INFORMATION PLEASE VISIT HTTP://WWW.HURRICANES.GOV/MARINE $$ NR