Rain and strong SE'ly winds extending across the Northern Isles on Friday. Turning drier and brighter later, as strong SE'ly winds ease a little and veer SW'ly.

Though there are likely to be some showers around, the weekend will see a fair amount of dry weather with sunny or clear spells. Quite breezy though, with SW'ly winds increasing fresh at times.

Cloudy on Monday, with rain and strong SW'ly winds. The remainder of next week unsettled and windy. Turning cooler later, as strong SW to W'ly winds veer NW'ly.

GENERAL SITUATION AND SYNOPSIS 06:00 UTC
Squeezed up against a large anticyclone over Scandinavia, a frontal trough will make very slow progress across the Northern Isles today. On the north side the airflow is strong SE'ly, but a lighter S to SE'ly on the south side.

The front will eventually clear Fair Isle later today, and the rest of Shetland tonight, to leave a lighter S to SE'ly airflow across the Northern Isles. However, a strengthening S or SE'ly will follow by Friday, as a small low centre swings past northwest Scotland.

During the weekend, as pressure remains low in the Iceland area, we will see the dominant high over Scandinavia easing away into Russia, while another in the Atlantic ridges northeast across southern Britain. As a result, the persistent SE'ly airflow will be replaced by one from a SW to W'ly direction.

An unsettled and strong W'ly airflow is expected to cover the Northern Isles during the first half of next week. Later, with Atlantic high pressure predicted to ridge north - as a depression over Iceland moves east into Scandinavia - the strong W'ly airflow may veer N'ly, introducing cooler air by the following weekend.

FORECAST FOR NEXT THREE DAYS
Confidence level: Weather type - medium. Timing - medium.
Temperatures ranging from a daytime high of 14° or 15° Celsius down to an overnight low of 11° or 12° Celsius.

THURSDAY 9th: Orkney beginning rather cloudy and misty with outbreaks of rain. Becoming drier and brighter during the morning, with some sunny spells by this afternoon. However, the North Isles may well remain cloudy with a little rain until later. With F5 SE'ly winds easing F2-3 S to SE'ly, patchy fog could affect eastern shores and hills at times. Shetland will stay dull all day, with outbreaks of occasionally heavy rain. It will be misty, with fairly extensive hill fog. SE to E'ly winds will remain F5-6 for much of the day, but ease F3-5 later. Rain across Shetland will eventually die out later this evening. Then much of tonight will be mostly dry - possibly with a few clear spells - but also the likelihood of mist and fog patches. Winds will be F3-4 SE'ly. Later in the night cloud will thicken across Orkney, with patchy rain possible by morning. SE'ly winds will also begin to freshen.
Sea state - Moderate to slight around Orkney, with a 1 to 2 metre SE'ly wind-swell. In Shetland waters rough at first, with a 3 metre SE'ly wind-swell. Later becoming generally moderate to slight, with a 1 to 2 metre S to SE'ly wind-swell.

FRIDAY 10th: During the morning, cloud and rain accompanied by F6 SE'ly winds will extend across the Northern Isles. Through the afternoon, Orkney will see drier, brighter weather arrive from the southwest, this improvement reaching Shetland by the evening. With the clearance, strong SE'ly winds will veer F5 SW'ly.
Sea state - Overnight becoming mainly slight, with a 1 metre S'ly wind-swell. Steadily increasing rough, with a 3 to 4 metre wind-swell by the afternoon, this SE'ly in direction at first, but becoming SW'ly by evening.

SATURDAY 11th: Starting bright with sunny spells and scattered showers. F4 S or SW'ly winds at first, but later veering SW'ly and increasing F5, as more frequent showers spread in from the southwest towards evening.
Sea state - Overnight becoming moderate or rough, with a 2 to 3 metre SW'ly wind-swell in western waters and around Shetland. Moderate with a 2 metre S'ly wind-swell east of Orkney.

10-DAY OUTLOOK
Confidence level: Weather type - medium. Timing - medium/low.
Temperatures in the daily range 13° to 15° Celsius down to about 10° Celsius. Probably a degree or so cooler later.

SUNDAY 12th: Sunny or clear spells, scattered showers and fresh SW'ly winds. The showers becoming more frequent and possibly merging into a longer spell of rain during the evening.
Sea state - Overnight becoming moderate or rough, with a 2 to 3 metre W'ly wind-swell.

MONDAY 13th: Mostly cloudy, with rain at times and fresh to strong SW'lywinds.

TUESDAY 14th - THURSDAY 16th: Strong SW to W'ly winds, with rain or showers and drier interludes between.

FRIDAY 17th - SUNDAY 19th: Perhaps turning cooler as winds veer NW'ly. Strong at first, winds may ease by the weekend.

Be aware that the weather over north-west Europe - and especially around the Northern Isles - is part of an ever-changing and dynamic system. Therefore regard the '10-Day Outlook' as a guide only - there are times when any outlook going beyond about 36 to 48 hours is likely to prove unreliable.

Always check the latest forecast from the UK Met Office before undertaking any weather-dependent activity.
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