2100 UTC Saturday 25 February to 2100 UTC Tuesday 28 February 2017
Issued by the Met Office, on behalf of the Maritime and Coastguard Agency, at 232157 UTC
On Saturday evening a ridge of high pressure will extend across the UK, however a frontal trough will extend across Scandinavia and into eastern Cullercoats from a low pressure northeast of Iceland. This will clear east overnight, with the ridge extending across Cullercoats for much of Sunday, however developing Atlantic low pressure systems could affect the northwest of the region, with low centred 975 Fair Isle by midnight. This is likely to persist during Monday, whilst a second low centre moves southeast into the southwest of the UK. During Tuesday, the low across Fair Isle then moves south, to be centred Forties 980 by the evening. Gales are likely Saturday evening north of 59N and also south of 56N. Further gales likely across Fair Isle Sunday morning, and then also south spreading north from south Cullercoats during the evening. These continue at times across Fair Isle and Viking on Monday and Tuesday
On Saturday evening, a ridge of high pressure will extend across Niton and the UK. During Sunday, a frontal trough could move northeast across the northwest of Niton. Atlantic low pressure systems will also develop into a broad system to the south of Iceland, and gradually move southeast towards the UK. By midnight, the Azores high will ridge north towards Greenland. This will lead to the developing low pressure moving southeast, into Shannon by midday on Monday with centre 973. This then moves southeast across the southwest of the UK, into Brittany as a gradually filling feature. Gales are expected across Shannon and Sole on Saturday evening, before spreading east to Fastnet, Lundy, Plymouth and Irish Sea through Sunday, with strong winds elsewhere. Further gales are then expected across the same area at first Monday, before spreading across Niton, with severe gales possible across Shannon, Sole and Fitzroy
On Saturday evening a ridge of high pressure will extend across the UK and towards Iceland. A developing low pressure will become centredd 964 west of Bailey by midnight, whilst a broader low pressure will slowly move southeast, southwest of Iceland. During Sunday these systems combine to give a broad area of low pressure, centre 967 west of Bailey. A smaller scale low pressure will also develop and become centred 975 Fair Isle. The first low pressure will move southeast Monday and filling to be centred 977 Fastnet by midnight, whilst the centre across Fair Isle persists. These clear during Tuesday, whilst a ridge of high pressure extends from the Azores towards Iceland. Gales are likely Saturday evening west of 09W, extending northeast during Sunday morning. Further gales likely south of 55N Sunday afternoon, and Monday, perhaps turning Severe across Shannon. Gales also possible across Fair Isle Monday, and spreading into Faeroes Tuesday
Extended outlook overview
The extended outlooks are issued once a day, at 2300 GMT and cover the next 3 to 5 days.
For the extend outlooks the waters surrounding the British Isles are divided into three areas; Cullercoats, Portpatrick and Niton. These three areas reflect the coverage areas of the UK's Navtex transmitters, which overlap in some areas.
The extended outlook forecast contains details of the likelihood of gales or storms, a general synopsis and a general forecast for the area of coverage of each Navtex transmitter.
In the UK, the Maritime & Coastguard Agency (MCA) is responsible for the provision of Maritime Safety Information (MSI) to ships at sea, which includes the broadcast of warnings and forecasts. The Met Office initiates warnings and prepares routine forecasts for dissemination on behalf of the MCA.
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