Starting dry and bright today but some showery rain possible for the afternoon. SW値y winds freshening. Becoming mainly dry this evening and at first tonight, but rain moving across Orkney towards dawn. Freshening SE値y winds.
Dry at first in Shetland on Saturday otherwise cloudy with outbreaks of occasionally heavy rain. SE to E値y gales developing. Becoming colder on Sunday with blustery showers turning wintry. Strong to gale-force W to NW値y winds veering fresh NW to N値y.
Bright on Monday and Tuesday with occasionally wintry showers and strong to gale-force W to NW値y winds. The rest of the Outlook perhaps starting unsettled and changeable with showers or bands of rain and fresh, occasionally strong, predominantly W値y winds with the chance of gales.
GENERAL SITUATION AND SYNOPSIS 06:00 UTC 27/03/2015
An overnight ridge of high pressure will decline today as a developing low moves towards Ireland. This low is expected to track northeast close to the Northern Isles during Saturday before moving away as a filling feature. A further shallower low may follow a similar track across northern Scotland later on Sunday or on Monday.
The outlook for next week suggests low pressure to the north and an anticyclone to the southwest is likely to result in a zonal W値y airflow. This would bring a changeable and strong SW to NW値y airflow over the Northern Isles as depressions track east from Iceland.
FORECAST FOR NEXT THREE DAYS
Temperatures in the range around 7ｰ Celsius by day down to 4ｰ or 5ｰ Celsius overnight. A degree or so cooler on Sunday.
FRIDAY 27th: Starting dry and bright but thickening cloud bringing outbreaks of showery rain for the afternoon. Light W値y winds backing SW値y and freshening F6. Turning drier and clearer later as winds ease. Mainly cloudy with occasional showers during the evening. Turning dry during the early hours, but rain moving across Orkney around dawn. SE値y winds freshening F5-6.
Sea State: Moderate to rough, with a 2 to 3 metre SW値y wind swell. Highest in the west.
SATURDAY 28th: Shetland perhaps starting dry otherwise cloudy with outbreaks of rain, heavy at times, as strengthening SE to E値y winds reach gale F8. Winds perhaps easing for a time later as rain turns showery. Strong to gale force W to NW値y winds with blustery showers expected later but easing again overnight.
Sea State: Moderate to rough, with a 2 to 4 metre SE値y wind swell turning E値y and later N値y.
SUNDAY 29th: Sunny spells and showers, these wintry later. F4-5 W to NW値y winds strengthening F5-7 later.
Sea State: Moderate to rough, with a 2 to 3 metre W値y wind swell.
TEN DAY OUTLOOK
Highs of 7ｰ or 8ｰ Celsius by day down to a low of 3ｰ or 4ｰ Celsius overnight at first. A degree or so milder later.
MONDAY 30th: Bright with occasionally heavy wintry showers with hail and risk of thunder. Strong to gale-force W値y winds perhaps easing for a time.
Sea State: Moderate to rough becoming rough to very rough, with a 2 to 3 metre SW値y wind-swell building 3 to 5 metres and turning W値y. Highest in the west.
TUESDAY 31st: A cold day with wintry showers and strong W to NW値y winds.
Sea State: Perhaps rough to very rough, with a 3 to 5 metre W or NW値y wind swell. Highest in the west.
WEDNESDAY 31st - MONDAY 6th: Wednesday cold with wintry showers and strong NW値y winds. The rest of the week perhaps seeing showers or bands of rain and fresh, occasionally strong, perhaps predominantly W値y winds with the chance of gales.
Sea State Wednesday: Possibly rough to very rough, with a 4 to 6 metre NW値y wind swell. Highest in the west.