Special Features

East Atlantic Gale Warning: Meteo-France has issued a gale warning, in effect for the high seas zones of Irving, west of Madeira, and Meteor, until 20/00 UTC at least, with severe gusts. Please refer to the next Special Feature for details on associated very 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: Very 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 into Sat night, mainly N of the Cape Verde Islands and east of 43W. Seas across these northeastern waters will then gradually reduce in areal coverage with the remaining very rough seas subsiding below 12 ft near the Canary Islands 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 through the coast of Sierra Leone near 08N13W, then curves southwestward to 02N34W. The ITCZ continues from 02N35W to 00N43W. Scattered moderate to isolated strong convection is noted from 02N to 05N between 13W and 20W and S of 04N between 20W and 43W.

Gulf Of America

A 1025 mb high pressure centered over the Florida Panhandle extends a ridge SW across the basin. The pressure gradient between this ridge and a stationary front SE of the area is leading to fresh to locally strong NE winds across the SE Gulf, along with moderate to locally rough seas. Elsewhere, mainly moderate NE winds and moderate seas prevail. Over the NW Gulf, winds are light to gentle, and seas are slight.

For the forecast, the pressure gradient between a ridge across the Gulf region and a weakening stationary front over the NW Caribbean Sea will continue to support fresh to locally strong NE winds and moderate to rough seas over the SE Gulf, including the Straits of Florida, through Fri. Moderate to fresh NE winds are expected nightly, through the forecast period, across the eastern Bay of Campeche due to local effects associated with a thermal trough. Elsewhere, gentle to moderate winds and slight to moderate seas will prevail through early next week.

Caribbean Sea

A weakening stationary front extends along 79W from central Cuba to just offshore NE Nicaragua near 15N, with a surface trough paralleling the boundary about 90 nm to the east. As these features weaken, significant convection associated with them has dissipated this evening. Fresh N winds prevail W of the front, with seas to 8 ft. To the east of these features, gentle to moderate E winds and moderate seas prevail.

For the forecast, fresh to locally strong N winds and moderate to rough seas will continue to follow the stationary front until it dissipates Fri offshore Nicaragua. Afterward, moderate to fresh NE winds will remain in the western Caribbean, including the lee side of Cuba and the Windward Passage through early Sun as high pressure develops across the northern Bahamas in the wake of the front. As the ridge shifts slightly eastward, fresh to strong winds will develop offshore Colombia early next week.

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 across the far NE waters.

A stationary front extends from 1012 mb low pressure lifting northward from Bermuda to 31N70W to the Central Bahamas and central Cuba. A pre-frontal trough extends from near 28N70W through the SE Bahamas to just offshore eastern Cuba. Numerous moderate to isolated strong convection is present E of this trough, from 15N to 30N between 65W and 70W. W of the front, fresh to strong NE winds and rough seas are present.

In the east Atlantic, a cold front arches from the Canary Islands to 22N28W to 31N38W. Strong N winds and rough to very rough seas are N of this front, with hazardous marine conditions in association with this front depicted further in the aforementioned Special Marine section above. The rough seas in NE swell extend much farther S and W, reaching to 15N and as far W as 55W.

Between these two frontal systems and across the remainder of the basin, an expansive 1031 mb ridge centered near 38N45W dominates. This is leading to moderate to fresh mainly E winds S of the high across area waters, with moderate seas.

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

Posted 0 minutes ago by NHC Forecaster Konarik