Special Features

East Atlantic Gale Warning: A gale-warning is in effect, issued by Meteo-France, for the high seas zones of Irving, west of Madeira, and Meteor until 19/12 UTC at least, with severe gusts. Please refer to the next Special Feature for details on associated large swells. Please refer to the high seas forecast issued by Meteo- France on the website: https://wwmiws.wmo.int for more details.

East Atlantic Long-period N Swell: Large, long-period north swell generated by a large fetch of gale to storm-force winds in the northeast Atlantic will continue to propagate southward of 31N through the weekend. Expect seas of 12-24 ft through Sat mainly N of the Cape Verde Islands and east of 43W. Seas across these northeastern waters will then gradually reduce in areal coverage and subside below 12 ft near the Canary Islands on Mon. Please refer to the latest High Seas Forecast issued by the National Hurricane Center at website https://www.nhc.noaa.gov/text/MIAHSFAT2.shtml for more details.

Monsoon Trough/ITCZ

The monsoon trough enters the Atlantic near 08N12W then curves southwestward to 03N18W. The ITCZ continues from 03N18W to the coast of Brazil near 01S48W. Scattered moderate isolated strong convection is noted from 01N to 05N between 07W and 22W, and S of 05N between 24W and 61W.

Gulf Of America

A surface ridge is anchored by a 1031 mb high pressure over the United States Mid-Atlantic region extends a ridge southward basin-wide, supporting moderate to fresh NE winds across the SE half of the basin along with 4 to 7 ft seas, except higher near and in the Yucatan Channel, where a tighter pressure gradient continues due to a lingering frontal boundary over the NW Caribbean. Winds are gentle to moderate at E-SE with 2 to 5 ft seas elsewhere.

For the forecast, the pressure gradient between a ridge across the Gulf region and a frontal boundary over the Caribbean Sea will support moderate to fresh N to NE winds and moderate to rough seas over the SE Gulf and the Straits of Florida to Fri. Moderate to fresh NE winds are expected across the eastern Bay of Campeche at night through Sat night. Elsewhere gentle to moderate winds and slight to moderate seas will prevail through Sun.

Caribbean Sea

A stationary front extends from Cuba near 23N80W to the Gulf of Honduras. A surface trough is analyzed along to the east of the front, from near the Cayman Islands at 20N80W to the SW Caribbean at 12N80W. Low level convergence induced by both the front and the pre-frontal trough continue to support scattered showers over the NW basin, mainly N of 14N and W of 75W. Fresh to strong northerly winds with seas of 5 to 9 ft prevail N of the front. Across the central and eastern basin E of the trough, fresh to locally strong E-SE trade winds and seas of 5 to 8 ft prevail. Gentle to moderate winds are across the remainder of the waters near the trough axis, including in the SW Caribbean, with seas of 3 to 6 ft.

For the forecast, a stationary front extends from western Cuba to the Gulf on Honduras. Fresh to locally strong N winds and rough seas follow the front. On Thu, the frontal boundary will drift eastward, with the fresh to locally strong N winds spilling just offshore Nicaragua in the wake of the front. This system is forecast to dissipate by Fri. This weather pattern should decrease the influence from the Atlantic ridge over the east and central Caribbean allowing winds and seas to diminish through Sat.

Atlantic Ocean

Refer to the Special Features section for details on an east Atlantic Gale Warning issued by Meteo-France, and associated large northerly swells.

A stationary front extends from 31N70W to the NW Bahamas and western Cuba. Heavy showers associated with the front continue to affect the Bahamas, the Great Bahama Bank, the Florida Straits, SE Florida Seaboard and within 240 nm E of the front between the Bahamas and Bermuda. Mostly fresh NE winds prevail W of the front, where seas are 5 to 9 ft E of 80W, and 3 to 6 ft across the Florida coastal waters, higher in the gulfstream.

A broad ridge centered on a 1034 mb high near 37N45W dominates most of the rest of the Atlantic between the front and 25W. Fresh to near gale-force winds are found N of 23N and E of 40W to the coast of Africa associated with the gale to storm force system discussed in the Special Features section. Fresh to strong winds under a relatively tight pressure gradient are found elsewhere from 18N to 28N between 35W and 55W. Mainly moderate to fresh trades dominate the remainder of the basin E of the stationary front. Seas are 4 to 7 ft over the SE waters S of 20N and E of 35W including across the Cabo Verde Islands, and 7 to 11 ft across the remainder of the waters.

For the forecast west of 55W, the stationary front will remain nearly stationary from near Bermuda to the central Bahamas on Thu. A weak low pressure is forecast to develop along the frontal boundary late Thu into Fri, and move quickly NE and N of the forecast area by Sat. This will tighten the pressure gradient, supporting fresh to strong winds and rough seas on either side of front and across the offshore forecast waters N of 25N through the weekend as this system then transitions to a cold front and moves east of the area.

Posted 0 minutes ago by NHC Forecaster Lewitsky