AXNT20 KNHC 240420

Tropical Weather Discussion
NWS National Hurricane Center Miami FL
1220 AM EDT Sat Mar 24 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 0000 UTC surface analysis and satellite imagery through 0400 UTC.



A combination of strong surface high pressure ridging southward along the U.S. east coast and relatively strong low pressure over northern South America is expected to support winds to gale force near the coast of Colombia beginning this evening. The gale force winds will not be continuous but are expected to recur each night during the evening and overnight hours through the end of next week while this surface weather pattern persists. 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 are forecast to develop by 00Z Sun for the following areas: AGADIR and TARFAYA. This is expected to be a relatively prolonged event and gale conditions could persist in these areas until 00Z Tue.


The monsoon trough extends from Guinea on the African coast near 10N13W to 05N17W. The ITCZ continues from 05N17W to 02N24W to 01N31W to the northeast coast of Brazil near 03S45W. Scattered moderate and isolated strong convection is present in an area bounded by 07N12W to 01N05W to 03N33W to 07N12W and from 03S to 01N between 38W and 46W.



Fair weather prevails across the entire Gulf of Mexico as double- barreled 1024 mb surface high pressure centered over the NE Gulf near 29N84w and off the NE Florida coast near 30N80W combine with abundant dry air in the mid- and upper-levels of the atmosphere to maintain the dry weather pattern. Moderate to fresh surface winds are out of the northeast to east over the eastern and central Gulf and east to southeast over the western Gulf. Sea heights are highest, near 7 ft, in the NW Gulf due to the longer fetch there. The area of surface high pressure is expected to gradually shift ESE during the next several days, causing winds to veer from the south over much of the region. This flow will cause sea heights to increase a little over the northwestern waters. Surface troughing is expected to develop over the Yucatan Peninsula each day, then migrate W into 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.


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 Caribbean Sea 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 near the coast of Colombia, and these 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 basin through the first half of next week.


A slow moving cold front enters the discussion area near 32N58W and continues southwestward to 24N66W, then continues as a weakening cold front to N of the Dominican Republic near 21N70W. Scattered showers and isolated thunderstorms are observed along and up to 60 nm SE of the front N of 25N, while cloudiness and patchy rain are seen along and up to 90 nm NW of this boundary N of 25N. West of the front, surface high pressure dominates the area with NW to NE flow and cooler air covering the western Atlantic. Expansive surface high pressure dominates the central and eastern Atlantic Ocean. Strong 1034 mb high pres centered near 35N35W ridges WSW to N of the Leeward Islands near 22N62W. This high is producing fresh trade-wind flow across a large portion of the tropical and subtropical eastern Atlantic waters, except for the waters W of 55W, where moderate trades are noted. An upper- level low centered near 26N34W is triggering isolated showers and thunderstorms from 16N to 18N between 31W and 39W.

The front over the central-western Atlantic is expected to slowly shift eastward and weaken while another boundary enters the far northwestern waters this weekend.

For additional information please visit http://www.hurricanes.gov/marine

$$ McElroy