Monday starting cloudy with some rain, but becoming brighter later. A mixture of showers or longer periods of rain and bright spells midweek, then perhaps drier with freshening S'ly winds.


GENERAL SITUATION AND SYNOPSIS 06:00 UTC
With an anticyclone centred to the west of the UK and pressure low over Scandinavia, a fresh to strong NW'ly airflow covers the Northern Isles.

While little change is expected today, by Saturday - with the anticyclone drifting a little south, while expected to ridge north towards Iceland - a cold front moving south over the Northern Isles will bring a slightly cooler NW to N'ly airflow.

This is expected to fall light later in the weekend, as the high moves to a position south of the UK and the Northern Isles falls within the 'col' area between this high and another north of Iceland. However, the earlier front is likely to be slow-moving over the north of Scotland.

With high pressure predicted to drift away into the near-Continent - while an area of low pressure develops to the northwest of the British Isles - later next week, we will probably see a strengthening airflow from between S and W'ly. At this point, it is possible high pressure may maintain its influence northwest over the North Sea, and thus keep Atlantic fronts away from the Northern Isles.


FORECAST FOR NEXT THREE DAYS
Confidence level: Weather type - high. Timing - high/medium.
Temperatures rising to 7° or 8° Celsius by day, falling to around 4° Celsius overnight.

FRIDAY 12th: Though bright or sunny spells are likely, it will be mostly cloudy with a few mainly light showers. During the evening, thicker cloud may bring patchy rain or drizzle with some hill fog to Shetland. Feeling cool in a F5 - locally F6 - NW'ly wind, which will be backing W or WNW'ly later. Much of the night then cloudy with an occasional light shower, but also one or two clearer spells. Fresh NW'ly winds.
Sea state - Moderate or slight in Orkney waters, with a 1 to 2 metre WSW'ly swell. Moderate through the Fair Isle Channel and northwards, but rough with a 3 metre swell northeast of Shetland.

SATURDAY 13th: Bright with showers, these perhaps more frequent and heavier for a time during the afternoon. F5-6 WNW'ly winds - perhaps easing F5 for a time - veering F5-6 NW to N'ly by the evening, as clearer conditions with fewer showers move south through Shetland and then Orkney.
Sea state - Moderate or slight in Orkney waters, with a 1 to 2 metre WSW'ly swell. Moderate through the Fair Isle Channel and northwards, but rough with a 3 metre swell northeast of Shetland.

SUNDAY 14th: Bright with scattered showers, these dying out by the afternoon as F4-6 NW'ly winds back W'ly and ease F3-4.Thickening cloud may bring a little rain from the south into Orkney and perhaps Fair Isle overnight.
Sea state - Moderate or slight in Orkney waters, with a 1 to 2 metre WSW'ly swell. Moderate through the Fair Isle Channel and northwards, but rough with a 3 metre swell northeast of Shetland.


10-DAY OUTLOOK
Confidence level: Weather type - medium. Timing - low/medium.
Temperatures in the daily range 7° Celsius down to around 5° Celsius. Possibly a degree or so milder later in the week.

MONDAY 15th: Cloudy with outbreaks of rain at first, but turning drier and brighter later. Moderate or light NW'ly winds.

TUESDAY 16th - WEDNESDAY 17th: Scattered showers or longer spells of rain, with brighter interludes between. Moderate or light SW to W'ly winds.

THURSDAY 18th - MONDAY 22nd: Perhaps mainly dry though cloudy, with fresh or strong and milder SW'ly winds.


DISCLAIMER

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.]]>