000 AXNT20 KNHC 271209 TWDAT Tropical Weather Discussion NWS National Hurricane Center Miami FL 709 AM EST Tue Feb 27 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... A strong 968 mb low pressure system with storm force winds centered over the north-central Atlantic near 38.5N32W supports a cold front from 38N17W to 26N30W to 26N53W. A tight pressure gradient associated with the deep low pressure and cold air advection associated with cold front are supporting gale force winds north of the front and east to 39W. Gale conditions are forecast to prevail through tonight then will gradually diminish as the low pressure moves farther away from the area and the front dissipates. Gale force winds are also occurring ahead of the front as noted in an earlier scatterometer pass, impacting the area east of 30W to the Canary Islands. Altimeter satellite passes are showing seas of 15 to 30 ft in northerly swell north of 20N and east of 50W. For more details, refer to the NHC High Seas Forecast under AWIPS/WMO Headers MIAHSFAT2/FZNT02 KNHC. ...MONSOON TROUGH/ITCZ... The monsoon trough enters the eastern Atlantic through the coast of Liberia near 06N11W to 02N17W, where it transitions to the intertropical convergence zone which continues to 00N24W to 01N36W to the coast of Brazil near 02S44W. Scattered moderate and isolated strong convection is present from 06S to 02N between 02W and 13W and from 05S to 04N between 24W and 29W. ...DISCUSSION... GULF OF MEXICO... A weakening stationary front reaches from near Panama City Florida to Brownsville Texas. Radar from the across the northern Gulf shows a few showers along and north of the frontal boundary, mainly over the northeast Gulf, and what may be light rain or drizzle in patches over the north central and northwest Gulf. A weak surface trough is moving W from the Yucatan Peninsula into the Bay of Campeche. No significant convection is associated with this feature. Dew points are in the upper 60s to lower 70s over the northwest Gulf, where platforms are showing areas of haze and fog. Light southeast winds are noted south of the front with 2 to 4 ft seas. For the forecast, the front will weaken through tonight. High pressure is building across the region and will be suppressing convection today through Wed night. Another, stronger cold front will move into the NW Gulf Wed night. Gale conditions are possible over the SW Gulf near Tampico Thu night and near Veracruz Fri morning following the passage of this front. CARIBBEAN SEA... High pressure north of the area centered between Bermuda and the northern Bahamas is supporting fresh to strong trade winds across the south central Caribbean and to the lee of Cuba. Moderate to fresh trade winds persist elsewhere. An upper-level low is centered north of the Mona Passage near 23N65W. A sharp trough extends SW from the low to Costa Rica. This trough is supporting a few showers over Hispaniola and over portions of the northeast Caribbean. Otherwise, convergent upper-level winds on the NW side of the trough are suppressing convection over the western half of the Caribbean. Little change is expected over the next several days as moderate to fresh winds generally prevail over the basin. Strong winds will continue pulsing along the N coast of Colombia during the late night and early morning hours. Strong winds will funnel through the Windward Passage through Thu. Large long period swells will reach the Atlantic passages in the Leeward and Windward Islands on Thu. ATLANTIC OCEAN... A weak pressure gradient resides over the Atlantic waters west of 50W. Gentle to light winds north of 22N and moderate trade winds south of 22N are generated by modest 1023 mb high pressure centered near 26N71W. A weakening cold front crosses the waters NW of the Bahamas from 32N73W to 30N81W. Cloudiness and isolated showers are occurring along and up to 150 nm SE of this boundary. Looking ahead, the cold front will weaken and continue heading SE to reach the central Bahamas Wed evening, as high pressure builds north of the front. Strong low pres passing north of the area will drag another cold front into the NW waters Thu night, with deteriorating conditions expected for the waters north of 27N and W of 65W. The system will support gales Fri night through Sat night over the waters N of 27N between 50W and 70W. A significant swell event will accompany this system, affecting all waters east of north Florida and Bahamas at the end of the week. East of 50W, fresh to strong northwest winds are observed from 25N to 30N E of 45W outside the areas of strong to gale force winds noted in the Special Features sections. Because the subtropical ridge is disrupted by the deep low pressure over the north central Atlantic, only gentle to moderate trade winds deeper into the tropics. Northerly swell of 8 to 12 ft is reaching as far south as 15N. Looking ahead for the waters east of 50W, winds and seas will gradually subside north of 25N through mid week, just ahead of another powerful low pressure system approaching from the western Atlantic, brining strong to near gale force winds and large seas to the area north of 20N between 40W and 50W by late week. For additional information please visit http://www.hurricanes.gov/marine $$ McElroy