000 AXNT20 KNHC 011102 TWDAT Tropical Weather Discussion NWS National Hurricane Center Miami FL 602 AM EST Thu Mar 1 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 1030 UTC. ...SPECIAL FEATURES... A 978 mb low pressure center is near 39N11W off Portugal. A cold front is connected with the low center, and it passes through Morocco and Western Sahara. Scatterometer passes over the past several hours continued to show gale force winds from 29N to 32N east of 23W, and Meteo France has forecast gale warnings for zones Irving, Madeira, and Agadir for the next 48 hours. ...MONSOON TROUGH/ITCZ... The monsoon trough passes through the coastal sections of Liberia near 06N10W to 01N12W. The ITCZ continues from 01N12W, crossing the Equator along 13W, to 04S24W, to 03S38W. Precipitation: widely scattered moderate to isolated strong from 03N southward from 09W eastward. isolated moderate to locally strong rainshowers from 13N southward between 30W and 50W, and elsewhere from 10N southward from 60W eastward. ...DISCUSSION... GULF OF MEXICO... Weak ridging extending from Tampa Florida to Tampico Mexico is supporting light to gentle winds over the eastern Gulf with 2 to 4 ft seas, and moderate to fresh southerly flow over the western Gulf with 4 to 6 ft seas. The moist southerly flow over the western Gulf is maintaining dewpoints into the lower 70s over the northwest Gulf, where platforms are indicated 4 to 5 nm in fog. The fresh southerly flow will diminish later this morning and the fog will lift as the ridge shifts eastward ahead of a cold front moving across the southern plains. The front will move into the northwest Gulf early Thu. Strong northerly winds will follow the front along the coast of Mexico until Fri evening. The front will stall from western Cuba to near Veracruz Mexico Fri night, then dissipate Sat. A ridge will build across the northern Gulf Sun and Mon. CARIBBEAN SEA... Buoy and scatterometer satellite data indicate moderate trade winds across the region currently. This is due to weakening high pressure north of the area, although the gradient is tight enough to support pulses of fresh to strong winds off Colombia this morning, and support fresh NE winds in the lee of Hispaniola. Seas are generally 3 to 5 ft, but range 5 to 7 ft in areas of stronger winds. Divergence aloft related to an upper level trough reaching from the Mona Passage to Panama is supporting a few trade wind showers from the Leeward Islands to the ABC Islands. Subsidence along the trough axis and to the west of the trough is inhibiting showers elsewhere. Looking ahead, high pressure north of the area will support moderate to locally fresh trade winds across the basin, with strong winds pulsing at night off Colombia through late week. Large NE swell will impact the tropical Atlantic waters through Sat, with an even more significant N swell event penetrating the NE Caribbean Sun night. ATLANTIC OCEAN... East of 60W, light to gentle winds persist across the region associated with weak ridging along 29N. Farther south, a dissipating trough persists along 24N through the central Bahamas. No significant shower or thunderstorm activity is noted. Recent buoy observations and a recent altimeter satellite pass indicated 7 to 9 ft seas north of 22N and east of the Bahamas, related to northeast swell. Looking ahead, the weak ridging along 29N will shift east ahead of a cold front moving off the NE Florida coast late today. The front will reach from Bermuda to SE Florida Fri afternoon, just ahead of a reinforcing front which will generate strong to gale force winds north of 27N east of 75W as deep low pressure moves off the Virginia coast. The fronts will merge Sat and stall from 22N65W to the Windward Passage by Sun before dissipating Mon. A significant swell event and likely the largest of this winter season will accompany this system, affecting all waters E of Florida and the Bahamas by the end of this week. West of 60W, a cold front reaches from 31N35W to 25N60W. Fresh northerly winds are noted north of the front. But the main weather impact continues to be large northerly swell dominating the entire region east of 60W. Various recent altimeter satellite passes indicate seas as high as 15 ft between 35W and 60W, and in excess of 20 ft east of 35W, mainly in the area of gales mentioned in the Special Features section. The swell will subside to 8 ft or less through Sun, just ahead of another significant swell event originating out of the north central Atlantic. For additional information please visit http://www.hurricanes.gov/marine $$ Christensen