000 AXNT20 KNHC 261105 TWDAT Tropical Weather Discussion NWS National Hurricane Center Miami FL 705 AM EDT Mon Mar 26 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 1100 UTC. ...SPECIAL FEATURES... ...GALE WARNING FOR THE SOUTH-CENTRAL CARIBBEAN SEA... A combination of a surface high pressure ridge over the western Atlc 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 at least Thu morning 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 N to NE winds are forecast to continue for the following areas: Portions of the AGADIR and TARFAYA zones adjacent to the coast of Morocco, and NE CANARIAS over the Canary Islands. Winds will diminish to strong northerly tonight. ...MONSOON TROUGH/ITCZ... The monsoon trough extends from Sierra Leone on the African coast near 07N12W to 03N15W. The ITCZ continues from 03N15W to 01N27W to the coast of Brazil near 03S42W. Scattered moderate and isolated strong convection is present from 03N to 07N between 11W and 15W. ...DISCUSSION... GULF OF MEXICO... A back door cold front has just entered the far NE Gulf and crosses the Florida Big Bend from near Apalachicola to Suwannee. Scattered showers are within 60 nm N of the front. Cloudiness and patchy rain are observed along and NW of the front. Otherwise, fair weather prevails across the remainder of the basin as expensive high pres ridges westward from the western Atlc 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 flow prevails across the basin, except for the NE third, where winds are light to moderate. Sea heights are highest, near 7 ft, in the NW Gulf due to the longer fetch of winds in this area. A larger and stronger high over the E coast of the United States will move S behind the cold front and produce more SE surface flow over the Gulf. 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. The next cold front will enter the NW Gulf on Wed night. 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. 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 continue across the basin as convergent upper-level flow on the south side of mid to upper- level troughing over the western Atlc maintains a relatively dry and subsident weather pattern over the basin. Trade winds are strongest over the waters N of the coast of Colombia. Winds are expected to reach gale-force during the evening and overnight hours. Winds will continue pulsing every night through Thu night/Fri morning. The current gale warning will expire this morning at 1200 UTC. 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 mid week. Winds will be fresh to strong over the Windward Passage and to the lee of Cuba during this time frame. ATLANTIC OCEAN... A cold front crosses the NW Atlantic from 32N65W to 29N70W to 28N76W to Cape Canaveral Florida near 28.5N81W. Scattered moderate and isolated strong convection is found along and up to 90 nm S of the front E of 78W. Cloudiness and patchy rain are seen N of the front and S of 31N. This front will continue moving SE and begin to weaken on Tue. The front will slow down as it weakens and eventually stretch from 32N53W to 25N57W to N of Puerto Rico near 19N67W by Wed night. A nearly stationary front extends SW over the central Atlantic from 32N48W to 22N61W, then continues as a dissipating stationary front to the Virgin Islands near 19N65W. Scattered moderate convection is observed within 30 nm of this boundary. This front is expected to weaken into a trough by tonight. Otherwise, expansive 1032 mb surface high pressure centered over the Azores near 38N24W ridges WSW all the way into the western Atlantic. The high is generating 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. For additional information please visit http://www.hurricanes.gov/marine $$ McElroy