Cloudy with some rain at first today then brighter with showers and strong W値y winds. Mostly dry tonight with winds easing a touch and veering NW値y.
Saturday mainly dry and bright with much lighter winds then rain and strengthening S値y winds in evening. Sunday brighter with a few showers, these more frequent later as SW値y winds veer fresh to strong W値y.
Some brighter spells during the first part of next week otherwise rather cloudy with showers or longer spells of rain. Fresh, occasionally strong SW to W値y winds. Possibly drier later as winds turn NW to N値y.
GENERAL SITUATION AND SYNOPSIS 06:00 UTC 22/05/2015
A cold front having cleared overnight the Northern Isles lies in the strong and showery W値y airflow of a depression over Iceland. This will veer NW値y later as a ridge moves in from the west.
High pressure, with a ridge across northern Scotland, is expected to drift east over the UK on Saturday, The next low, forecast to move east over Iceland, then driving Atlantic fronts across Scotland overnight. A freshening, showery SW to W値y airflow is likely on Sunday as the fronts clear.
Current predictions for the first part of next week suggest high pressure to the south and low pressure to the north of the UK may well bring a changeable SW to W値y airflow across northern parts. This possibly tending NW値y later as low pressure moves into Scandinavia and pressure builds over the Atlantic.
FORECAST FOR NEXT THREE DAYS
Daytime highs of 10ｰ or 11ｰ Celsius, perhaps 12ｰ Celsius for Kirkwall and 9ｰ Celsius on and near exposed western coasts. Overnight lows around 6ｰ Celsius.
FRIDAY 22nd: Cloudy with some patchy rain at first. This clearing then a brighter but showery day with F6-7 W値y winds, perhaps increasing gale F8 for a time. Later turning NW値y, easing F5. A mostly dry though rather cloudy night with a few showers, mainly across Shetland where winds are likely to remain fresh.
Sea State: Rough to very rough, with a 3 to 5 metre W to NW値y wind swell. Highest in the west.
SATURDAY 23rd: Some early showers, but soon becoming mostly dry and bright as F5 NW値y winds back F2-3 W値y. Clouding over through the afternoon as SW値y winds freshen F5 with rain by evening with strong S値y winds.
Sea State: Moderate to rough at first, with a 2 to 3 metre NW値y wind-swell. Highest in the west. Becoming mostly moderate, with a 2 metre S to SW値y wind-swell.
SUNDAY 24th: The rain clearing then bright with sunny spells and a few showers. These more frequent later as F5-6 SW値y winds veer F6 W値y. Winds turning NW値y overnight and perhaps easing across the north of Shetland.
Sea State: Moderate to rough, with a 2 to 3 metre SW to W値y wind-swell.
TEN DAY OUTLOOK
Temperatures in the daily range 10ｰ or 11ｰ Celsius down to around 6ｰ Celsius.
MONDAY 25th: Bright with some showers and a moderate to fresh NW値y wind. Possibly lighter across Unst and Yell.
Sea State: Perhaps moderate to rough, with a 2 to 3 metre W to NW値y wind-swell.
TUESDAY 26th: Perhaps bright with some showers and a fresh to strong W値y wind.
Sea State: Perhaps moderate to rough, with a 2 to 4 metre W値y wind-swell. Highest in the west.
WEDNESDAY 27th - SUNDAY 31st: Some showers on Wednesday with a fresh W値y wind. Then changeable with some of rain or showers and fresh or strong SW to W値y winds, but perhaps tending to a cool W to NW値y for a time later. Some short drier, brighter and less windy interludes can be expected.
Sea State Wednesday: Possibly moderate to rough, with a 2 to 4 metre W値y wind-swell. Highest in the west.