Met Office

Extended outlook

2100 UTC Tuesday 21 August to 2100 UTC Friday 24 August 2018

Issued by the Met Office, on behalf of the Maritime and Coastguard Agency, at 192022 UTC


On Tuesday evening high 1021 will be centred near Denmark, with a ridge of high pressure across the east and south of the Cullercoats area, but with frontal troughs bringing a stronger cyclonic flow to the northwest. The high then expected to move away east on Wednesday, allowing frontal troughs to transfer east across the area. A weak ridge over the North Sea early on Thursday will soon decline as further frontal troughs move from the west, and with low pressure developing in the northern North Sea by midnight Friday. Current indications are for low pressure to persist in the north of the Cullercoats area on Friday, but with a ridge of high pressure developing in the south. Near gale to gale force winds are expected north of 59 N and east of the Shetlands by midnight Wednesday, but these moderating from the west during Wednesday morning


On Tuesday evening a ridge of high pressure will extend northeast from the Azores high across much of the Niton forecast area, but with a frontal trough moving east into the northwest. The ridge then expected to decline for a time on Wednesday as the frontal trough moves southeast through the area, but with higher pressure then following to the northwest. Further weakening frontal troughs are expected to follow from the west on Thursday, but with a ridge of high pressure expected to extend northeast across all but the far east of the Niton area by midnight Friday. Current indications are then for the ridge to persist across much of the area during Friday. No gales are currently expected through this forecast period, but winds may become strong at times in the far northwest for a time on Thursday, and perhaps in the south of sea area Fitzroy on Friday


Lows 1001 are expected sea areas Hebrides and Southeast Iceland on Tuesday evening, with an associated frontal trough extending southwest to sea area Shannon. The lows then expected to transfer away northeast and deepen on Wednesday, with frontal troughs moving east across the Portpatrick area. A ridge of high pressure is then forecast to build from the southwest across southern and central parts of the area through Thursday, but with frontal troughs maintaining a more cyclonic flow in the far north. Some uncertainties for Friday, but current indications are for the ridge to decline as frontal troughs in the north transfer south, with a further ridge following to the far north. No gales are currently expected in the Portpatrick area through this forecast periods, but winds are likely be strong at times through central and southern parts during Wednesday and Thursday