000 AXNT20 KNHC 251153 TWDAT Tropical Weather Discussion NWS National Hurricane Center Miami FL 753 AM EDT Sun Mar 25 2018 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 0600 UTC surface analysis and satellite imagery through 1145 UTC. ...SPECIAL FEATURES... ...GALE WARNING FOR THE SOUTH-CENTRAL CARIBBEAN SEA... A combination of strong surface high pressure ridging southward along the U.S. east coast and relatively strong low pressure over northern South America supports winds pulsing to gale force near the coast of Colombia. The gale force winds will recur each night during the evening and overnight hours through the end of next week while this surface weather pattern persists. The current gale is forecast to continue until 12Z this morning over the area from 11N to 12N between 74W and 76W, with corresponding seas of 9 to 12 ft. For more details please see High Seas Forecasts issued by the National Weather Service under AWIPS/WMO headers MIAHSFAT2/FZNT02 KNHC. This information can also be found at the following website: www.nhc.noaa.gov/marine ...GALE WARNING for the METEO-FRANCE areas... Please refer to the METEO-FRANCE High Seas Forecast, that is listed on the website: WWW.METEOFRANCE.COM/PREVISIONS-METEO- MARINE/BULLETIN/GRANDLARGE/METAREA2. Gale-force winds N to NE winds are forecast to develop this evening for the following areas: Portions of the AGADIR and TARFAYA zones adjacent to the coast of Morocco. The gale conditions are expected to continue until this evening. Winds will become strong northerly from tonight through Mon night. ...MONSOON TROUGH/ITCZ... The monsoon trough extends from Sierra Leone on the African coast near 08N13W to 03N22W, where latest scatterometer data indicates the ITCZ continues then continues to 01N28W to below the Equator at 33W and to the northeast coast of Brazil near 02S44W. Scattered moderate and isolated strong convection is present within an area bounded by 01S05W to 03N28W to 06N14W to 01S05W. ...DISCUSSION... GULF OF MEXICO... Fair weather prevails across the entire Gulf of Mexico as 1022 mb surface high pressure centered off the Atlantic coast of N Florida near 28N72W ridges westward across the Gulf. Abundant dry air prevails as ridging at the mid and upper levels of the atmosphere extends over the Gulf. Moderate to fresh E to SE surface winds are noted over the eastern and central Gulf, while SE to S winds are observed over the western Gulf. Sea heights are highest, near 7 ft, in the NW Gulf due to the longer fetch in this area. The high pressure is expected to gradually shift ESE during the next several days. This high will be reinforced by stronger ridging building S along the E coast of the United States during this time frame. Developing low pres over the central plains states will tighten the pressure gradient over the Gulf and cause winds to become fresh to strong on Tue. Surface troughing is expected to develop over the Yucatan Peninsula each day, then migrate W over the Bay of Campeche during the evening and nighttime hours. Otherwise, fair weather is expected to continue through the weekend as dry air remains in place. CARIBBEAN SEA... Undersea volcano Kick'em Jenny, north of Grenada near 12.18N 61.38W, is in a state of unrest. The government of Grenada advises mariners to observe a 5 km or 3.1 nm exclusion zone around Kick'em Jenny. Please refer to the web page, www.nadma.gd, for additional information. Relatively quiet conditions exist across the basin as mid to upper-level ridging maintains a relatively dry and subsident weather pattern over the basin. Trade winds are strongest over the south-central waters N of the coast of Colombia. Winds are expected to reach gale-force during the evening and overnight hours through Thu night and Fri morning. See the SPECIAL FEATURES section above for more details. Otherwise, ridging extending southward from along the east coast of the united States will maintain moderate to fresh NE to E winds over the Caribbean basin through the first half of next week. Winds will be fresh to strong in the Windward Passage. ATLANTIC OCEAN... A slow moving cold front extends SW from 31N51W to 22N60W, then continues as a weakening stationary front to the northeast coast of Puerto Rico. Scattered showers and isolated thunderstorms are observed along and up to 120 nm E of the cold front mainly N of 27N. West of these fronts, surface high pressure centered just E of Florida dominates the area as NW to NE flow and cooler air covers the western Atlc. Expansive surface high pressure also dominates the central and eastern Atlantic Ocean. A 1030 mb high is centered over the E Atlantic just SW of the Azores near 37N29W with a ridge extending WSW reaching the NE of the Leeward Islands. This high is producing moderate to fresh trade winds across a large portion of the tropical and subtropical eastern Atlantic waters N of the ITCZ and W of 25W. The cold front currently over the west-central Atlantic will slowly shift eastward, then stall, weaken and dissipate. Another cold front will enter the far northwestern waters late Sun through Mon in conjunction with developing low pres SE of New England. For additional information please visit http://www.hurricanes.gov/marine $$ McElroy/JA/ERA