Sea Area Forecast
Forecast valid from: 06:00, Thursday 17 September 2026 until 06:00, Friday 18 September 2026
Small Craft Warning
Westerly winds will reach force 6 or higher at times today (Thursday) and tonight on all Irish coasts.
Gale Warning
Nil
Atlantic Swell
Heavy swell on Atlantic coasts from Thursday afternoon.
Meteorological Situation at 03:00 UTC
Ireland lies in a mostly fresh to strong westerly airflow with a depression of 975hPa, centred southwest of Iceland. Showerty troughs are embedded in the flow.
Small Craft Warning: In effect
Heavy Swell (>4m) : yes
Forecast for Slyne Head to Fair Head to Howth Head and for the North Irish Sea
Wind: Westerly force 5 to 7 and gusty. Backing southwesterly towards the end of the period.
Weather: Cloudy or fair with scattered showers, becoming isolated soon. Mostly cloudy later with rain, drizzle and mist in the west by the end of the period.
Visibility: Moderate to poor in precipitation and mist, otherwise good.
Forecast for Howth Head to Roches Point to Slyne Head and for the South Irish Sea
Wind: Westerly force 5 or 6 and gusty, reaching force 7 at times north of Valentia. Later decreasing force 4 or 5, occasionally force 6. Becoming southwesterly force 4 to 6 by the end of the period.
Weather: Cloudy or fair with scattered showers, becoming isolated soon. Mostly cloudy later with rain, drizzle and mist in the west by the end of the period.
Visibility: Moderate to poor in precipitation and mist, otherwise good.
Outlook for a further 24 hours until 06:00, Saturday 19 September 2026
Fresh to strong southwesterly winds, increasing strong to near gale force Friday morning, possibly touching gale force at times in the northwest and on the Irish Sea. Winds will decrease fresh to near gale force later. Weather: Rain, drizzle and mist spreading from the west Friday morning, clearing to showers from the northwest later but persisting in the south.
Forecast issued at: 06:00, Thursday 17 September 2026
All times are local unless specified
