000 AXNT20 KNHC 200516 TWDAT Tropical Weather Discussion NWS National Hurricane Center Miami FL 116 AM EDT Tue Mar 20 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 0500 UTC. ...SPECIAL FEATURES... ...ATLANTIC OCEAN GALE WARNING... The 24-hour forecast, starting at 20/0000 UTC, is for a cold front to be along 31N80W 30N81W. Expect: N of 29N E of the cold front to 76W, SW WINDS 25 to 35 knots. Seas ranging from 9 feet to 12 feet. The 48-hour forecast consists of: the cold front along 31N68W TO 25N72W TO 22N78W. N of 30N between 70W and 79W, W to NW WINDS 30 to 35 knots. Seas ranging from 9 feet to 17 feet. ...GULF OF MEXICO GALE WARNING... The 18-hour forecast, starting at 20/0000 UTC, is for a cold front to be along 29N83W 21N97W. Expect: N OF 26N W of the cold front to 93W, W to NW WINDS 20 to 25 knots with FREQUENT GUSTS to GALE FORCE WITHIN 30 NM OF THE COAST BETWEEN 83W AND 88W. Seas less than 8 feet. The 24-hour forecast consists of: the cold front from 27N82W to 20N97W, N of 26N between 83W and 91W, W to NW WINDS 20 to 25 knots with FREQUENT GUSTS TO GALE FORCE WITHIN 30 NM OF THE COAST BETWEEN 83W AND 88W. Sea heights ranging from 8 feet to 10 feet. ...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 for the area that is called: AGADIR, TARFAYA, and CANARIAS. The OUTLOOK, for the 24 hours that follow the forecast that is valid until 21/0000 UTC, consists of: the persistence of a N or NE near gale or gale in: AGADIR, TARFAYA, CANARIAS, and CAP BLANC. ...MONSOON TROUGH/ITCZ... The monsoon trough passes through the coastal sections of Sierra Leone near 08N13W, to 05N15W and 03N21W. The ITCZ continues from 03N21W to 02N27W, 01N32W, and 02N46W. Precipitation: isolated moderate to locally strong rainshowers, in a disorganized pattern, are from 10N southward from 60W eastward. ...DISCUSSION... GULF OF MEXICO... Please read the Special Features section for information about the gale warning in the Gulf of Mexico. Upper level westerly wind flow is moving across the open waters of the Gulf of Mexico. A cold front passes through SE Louisiana, to NE Mexico just to the south of the border with Texas, and then inland in Mexico to 28N106W. No significant deep convective precipitation is apparent in satellite imagery. Broken multilayered clouds are to the north of the line that passes through 21N97W 23N92W 24N86W 23N84W. The current cold front will shift SE across the forecast waters, moving SE of the area by early Wednesday. High pressure will build in the wake of the front. 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 webpage, www.nadma.gd, for additional information. Broad upper level anticyclonic wind flow spans the area. A surface ridge passes through the Atlantic Ocean, to SE Cuba near 21N78W, to the border of Costa Rica and Panama. High pressure north of the region will support fresh-to-locally strong trade winds across the south central Caribbean Sea during the next several days. Winds will reach near gale-force along the NW coast of Colombia during the overnight hours. ATLANTIC OCEAN... Please read the Special Features section for information about the gale warning in the Atlantic Ocean. A stationary front is along 31N76W to a 1006 mb low pressure center that is near 31N80W, inland, beyond SE Georgia. Precipitation: isolated moderate to locally strong rainshowers are from 27N northward from 72W westward. Broken multilayered clouds and other possible rainshowers are elsewhere from 26N northward from 56W westward. An upper level trough that is in the central Atlantic Ocean is supporting a cold front that passes through 32N53W to 30N55W. The cold front is dissipating from 30N55W to 28N60W and 25N71W. Isolated moderate to locally strong rainshowers are within 250 nm to the NW and W of the line that passes through 32N42W 25N47W 22N52W. Scattered to broken multilayered clouds are to the north of 22N52W 21N59W 21N70W. A surface ridge extends from a 1029 mb high pressure center that is near 33N27W, to 27N36W, 23N42W, to 19N58W, to SE Cuba near 21N78W, to the border of Costa Rica and Panama. The current dissipating cold front will move eastward tonight, across the waters N of 27N and E of 70W. S to SW wind flow will increase off NE Florida tonight and Tuesday, ahead of a stronger cold front that will be moving into the region late on Tuesday. Winds will reach gale-force north of 28N from Tuesday night through Wednesday night as the front moves eastward. The wind speeds and sea heights will diminish on Thursday, as the front reaches from Bermuda to the Windward Passage, then continues E and weakens slowly. For additional information please visit http://www.hurricanes.gov/marine $$ MT