


Offshore Forecast
Issued by NWS
Issued by NWS
476 FZNT31 KNHC 210904 OFFN20 Marine Weather HF Voice Broadcast NWS National Hurricane Center Miami, FL 504 AM EDT Thu Aug 21 2025 Marine Weather HF Voice Broadcast for the Tropical N Atlantic from 07N to 19N W of 55W, the N Atlantic from 19N to 31N W of 55W including the Bahamas, and the Caribbean Sea. Seas given as significant wave height, which is the average height of the highest 1/3 of the waves. Individual waves may be more than twice the significant wave height. Synopsis for Caribbean Sea and Tropical N Atlantic from 07N to 19N W of 55W .SYNOPSIS...Fresh to locally strong trades and moderate seas seas will exist over the central and eastern Caribbean through Fri as a strengthening pressure gradient develops between low pressure over Colombia and building high pressure in the wake of Hurricane Erin in the western Atlantic. Elsewhere, fresh to occasionally strong east to southeast winds will pulse in the Gulf of Honduras beginning tonight. Long period northwest to north swell from Hurricane Erin will begin to impact the Tropical N Atlantic zones from late on Fri through Mon. Looking ahead, shower and thunderstorm activity has become a bit more concentrated in association with a tropical wave located a few hundred miles east of the Leeward Islands. Environmental conditions appear conducive for further development of this system, and a tropical depression is likely to form this weekend while it moves near or to the north of the northern Leeward Islands. NW Caribbean W of 85W .TODAY...SE winds 10 to 15 kt. Seas 2 ft or less. .TONIGHT...E winds 10 to 20 kt. Seas 3 to 5 ft. .FRI...SE winds 10 to 20 kt. Seas 3 to 5 ft. .FRI NIGHT...SE winds 15 to 25 kt. Seas 3 to 5 ft. .SAT...E winds 15 to 25 kt. Seas 3 to 5 ft. .SAT NIGHT...E winds 15 to 25 kt. Seas 3 to 5 ft. .SUN...E winds 10 to 20 kt. Seas 3 to 5 ft. .SUN NIGHT...E winds 10 to 20 kt. Seas 3 to 4 ft. .MON...E winds 15 to 25 kt. Seas 3 to 5 ft. Caribbean N of 15N between 72W and 85W .TODAY...E winds 10 to 20 kt. Seas 3 to 5 ft S of 18N, and 2 ft or less elsewhere. .TONIGHT...E winds 10 to 20 kt. S of 18N, seas 3 to 5 ft. Elsewhere, seas 2 to 3 ft. .FRI...E winds 10 to 20 kt. Seas 4 to 6 ft S of 18N, and 2 to 4 ft elsewhere. .FRI NIGHT...E winds 10 to 20 kt S of 18N, and E 15 to 25 kt elsewhere. S of 18N, seas 3 to 5 ft. Elsewhere, seas 2 to 3 ft. .SAT...E winds 10 to 20 kt. Seas 3 to 5 ft. .SAT NIGHT...E winds 10 to 20 kt. S of 18N, seas 3 to 5 ft. Elsewhere, seas 2 to 3 ft. .SUN...E winds 10 to 20 kt. Seas 3 to 5 ft S of 18N, and 2 to 3 ft N of 18N. .SUN NIGHT...E winds 10 to 20 kt. Seas 3 to 5 ft. .MON...E winds 15 to 25 kt S of 18N, and E 10 to 20 kt elsewhere. Seas 4 to 6 ft S of 18N, and 3 to 4 ft N of 18N. Caribbean from 11N to 15N W of 72W .TODAY...E winds 15 to 25 kt. Seas 4 to 6 ft. .TONIGHT...E winds 15 to 25 kt within 90 nm of coast of Colombia, and E 20 to 30 kt elsewhere. Seas 4 to 6 ft. .FRI...E winds 15 to 25 kt. Seas 5 to 7 ft. .FRI NIGHT...E winds 15 to 25 kt. Seas 4 to 6 ft. .SAT...E winds 10 to 20 kt within 90 nm of coast of Colombia, and E 15 to 25 kt elsewhere. Seas 4 to 6 ft. .SAT NIGHT...E winds 15 to 25 kt. Seas 4 to 5 ft. .SUN...E winds 15 to 25 kt. Seas 4 to 6 ft. .SUN NIGHT...E winds 15 to 25 kt. Seas 5 to 7 ft. .MON...E winds 15 to 25 kt. Seas 5 to 7 ft. SW Caribbean S of 11N .TODAY...NE winds 10 to 20 kt. Seas 3 to 5 ft. .TONIGHT...NW winds 10 to 15 kt. Seas 3 to 5 ft. .FRI...NW winds 10 to 20 kt, shifting to SW in the afternoon. Seas 4 to 6 ft. .FRI NIGHT...W winds 10 to 20 kt. Seas 4 to 6 ft. .SAT...W winds 10 to 15 kt, shifting to SE in the afternoon. Seas 3 to 5 ft. .SAT NIGHT...S winds 10 to 15 kt. Seas 3 to 5 ft. .SUN...SW winds 10 to 15 kt. Seas 3 to 5 ft. .SUN NIGHT...N winds 10 to 15 kt. Seas 3 to 4 ft. .MON...W winds 10 to 15 kt. Seas 3 to 5 ft. Caribbean between 64W and 72W .TODAY...E winds 15 to 25 kt. Seas 4 to 6 ft. .TONIGHT...E winds 15 to 25 kt. Seas 4 to 6 ft. .FRI...E winds 15 to 25 kt Gulf of Venezuela, and E 10 to 20 kt elsewhere. Seas 3 to 4 ft Gulf of Venezuela, and 4 to 6 ft elsewhere. .FRI NIGHT...NE winds 15 to 25 kt Gulf of Venezuela, and E 10 to 20 kt elsewhere. Seas 3 to 5 ft. .SAT...NE winds 15 to 25 kt Gulf of Venezuela, and E 10 to 20 kt elsewhere. Seas 3 to 5 ft. .SAT NIGHT...E winds 15 to 25 kt. Seas 4 to 6 ft. .SUN...E winds 15 to 25 kt. Seas 4 to 6 ft. .SUN NIGHT...E winds 20 to 30 kt Gulf of Venezuela, and E 15 to 25 kt elsewhere. Seas 4 to 6 ft. .MON...E winds 15 to 25 kt. Seas 4 to 6 ft. Offshore Leeward Islands and adjacent ATLC waters from 15N to 19N W of 55W .TODAY...E winds 10 to 20 kt. Seas 5 to 7 ft. .TONIGHT...E winds 10 to 20 kt. Seas 4 to 6 ft. .FRI...SE winds 15 to 25 kt. Seas 4 to 6 ft. .FRI NIGHT...SE winds 10 to 15 kt. Seas 3 to 5 ft. .SAT...E winds 10 to 20 kt. Seas 4 to 6 ft. .SAT NIGHT...E winds 10 to 20 kt. Seas 4 to 6 ft. .SUN...E winds 10 to 20 kt. Seas 5 to 7 ft. .SUN NIGHT...E winds 10 to 20 kt. Seas 6 to 8 ft. .MON...E winds 10 to 20 kt. Seas 6 to 8 ft. Offshore Windward Islands and adjacent ATLC waters from 07N to 15N W of 55W .TODAY...SE winds 10 to 15 kt. Seas 4 to 6 ft. .TONIGHT...SE winds 10 to 20 kt. Seas 3 to 5 ft. .FRI...SE winds 10 to 20 kt. Seas 3 to 5 ft. .FRI NIGHT...E winds 10 to 20 kt. Seas 4 to 6 ft. .SAT...E winds 10 to 20 kt. Seas 4 to 6 ft. .SAT NIGHT...E winds 10 to 20 kt. Seas 4 to 6 ft. .SUN...E winds 10 to 20 kt. Seas 5 to 7 ft. .SUN NIGHT...E winds 10 to 20 kt. Seas 5 to 7 ft. .MON...E winds 10 to 20 kt. Seas 5 to 7 ft. Synopsis for the the SW N Atlantic including the Bahamas .SYNOPSIS...Hurricane Erin is located centered north of the area near 34.2N 72.1W at 5 AM EDT, and is moving north-northeast at 15 kt. Maximum sustained winds are 90 kt with gusts to 110 kt, and the minimum central pressure is 945 mb. Erin will will continue to pull NNE far away from the region through the end of the week while slowly weakening. Long period northerly swells generated by Erin will affect just about the entire forecast area through the next few days. In the wake of Erin, central Atlantic high pressure will build WSW toward the central Bahamas and the Straits of Florida through the period. Looking ahead, a tropical wave located several hundred miles east of the Leeward Islands is producing a broad area of disorganized showers and thunderstorms. Environmental conditions appear conducive for gradual development of this system, and a tropical depression is likely to form by this weekend while it moves near or to the north of the northern Leeward Islands. ATLC waters from 27N to 31N W of 77W .TODAY...W winds 10 to 20 kt. Seas 9 to 14 ft. .TONIGHT...SW winds less than 10 kt. Seas 7 to 10 ft. .FRI...W winds less than 10 kt, increasing to 10 to 15 kt in the afternoon. Seas 6 to 9 ft. .FRI NIGHT...S winds less than 10 kt. Seas 6 to 9 ft. .SAT...SW winds less than 10 kt. Seas 6 to 8 ft. .SAT NIGHT...SW winds less than 10 kt. Seas 5 to 7 ft. .SUN...W winds 10 to 15 kt. Seas 5 to 7 ft. .SUN NIGHT...W winds 10 to 15 kt. Seas 5 to 7 ft. .MON...W winds 10 to 15 kt. Seas 5 to 7 ft. ATLC waters from 27N to 31N between 65W and 77W ...TROPICAL STORM WARNING... .TODAY...TROPICAL STORM CONDITIONS POSSIBLE. W of 70W, SW winds 30 to 40 kt, becoming W 20 to 30 kt in the afternoon. Elsewhere, S winds 25 to 35 kt. Seas 12 to 17 ft. .TONIGHT...W of 70W, W winds 20 to 30 kt, diminishing to 10 to 20 kt late. Elsewhere, SW winds 20 to 30 kt. Seas 10 to 15 ft. .FRI...W winds 10 to 20 kt W of 70W, and SW 15 to 25 kt elsewhere. Seas 8 to 13 ft. .FRI NIGHT...W of 70W, NW winds 10 to 15 kt, diminishing to less than 10 kt after midnight. Elsewhere, W winds 10 to 20 kt. Seas 8 to 12 ft. .SAT...NW winds less than 10 kt, shifting to SW in the afternoon. Seas 8 to 12 ft. .SAT NIGHT...S winds less than 10 kt. Seas 8 to 11 ft. .SUN...W of 70W, SW winds 10 to 15 kt. Elsewhere, Variable winds less than 10 kt, becoming S less than 10 kt in the afternoon. Seas 7 to 10 ft. .SUN NIGHT...SW winds 10 to 15 kt. Seas 7 to 8 ft. .MON...SW winds 10 to 20 kt. Seas 6 to 8 ft. Bahamas N of 22N .TODAY...SW winds 10 to 15 kt. Seas 4 to 6 ft. .TONIGHT...W winds 10 to 15 kt, shifting to S late. Seas 3 to 5 ft. .FRI...S to SW winds 10 to 15 kt. Seas 3 to 4 ft. .FRI NIGHT...N winds less than 10 kt, shifting to SE after midnight. Seas 3 to 5 ft. .SAT...S winds less than 10 kt. Seas 3 to 5 ft. .SAT NIGHT...SE winds less than 10 kt. Seas 3 to 5 ft. .SUN...S winds less than 10 kt. Seas 3 to 5 ft. .SUN NIGHT...SE winds 10 to 15 kt. Seas 3 to 5 ft. .MON...SE winds 10 to 15 kt. Seas 3 to 5 ft. ATLC waters from 22N to 27N between 65W and the Bahamas .TODAY...S winds 10 to 20 kt. Seas 7 to 10 ft. .TONIGHT...S winds 10 to 20 kt. Seas 6 to 9 ft. .FRI...S winds 10 to 15 kt. Seas 6 to 8 ft. .FRI NIGHT...W of 70W, W winds less than 10 kt. Elsewhere, NW winds 10 to 15 kt, shifting to N after midnight. Seas 6 to 8 ft. .SAT...SW winds less than 10 kt. Seas 6 to 9 ft. .SAT NIGHT...NW winds less than 10 kt, shifting to S after midnight. Seas 7 to 9 ft. .SUN...S winds 10 to 15 kt. Seas 7 to 9 ft. .SUN NIGHT...S winds 10 to 15 kt. Seas 7 to 8 ft. .MON...S winds 10 to 15 kt. Seas 6 to 7 ft. ATLC waters S of 22N W of 65W .TODAY...SE winds 10 to 20 kt. Seas 3 to 5 ft. .TONIGHT...E winds 10 to 20 kt. Seas 3 to 5 ft. .FRI...E winds 10 to 20 kt. Seas 3 to 5 ft. .FRI NIGHT...E winds 10 to 20 kt. Seas 3 to 5 ft. .SAT...E winds 10 to 15 kt. Seas 4 to 6 ft. .SAT NIGHT...E winds 10 to 15 kt. Seas 4 to 6 ft. .SUN...E winds 10 to 15 kt. Seas 4 to 6 ft. .SUN NIGHT...E winds 10 to 15 kt. Seas 4 to 6 ft. .MON...E winds 10 to 20 kt. Seas 5 to 7 ft. ATLC waters from 19N to 22N between 55W and 65W .TODAY...E winds 10 to 20 kt. Seas 5 to 7 ft. .TONIGHT...E winds 10 to 20 kt. Seas 6 to 7 ft. .FRI...E winds 10 to 20 kt, becoming SE 20 to 30 kt in the afternoon. Seas 6 to 8 ft. .FRI NIGHT...SE winds 10 to 20 kt. Seas 5 to 7 ft. .SAT...SE winds 10 to 20 kt. Seas 5 to 7 ft. .SAT NIGHT...SE winds 10 to 15 kt. Seas 6 to 8 ft. .SUN...E winds 10 to 15 kt. Seas 6 to 8 ft. .SUN NIGHT...E winds 10 to 15 kt. Seas 7 to 8 ft. .MON...E winds 10 to 15 kt. Seas 8 ft.