Updated: Friday, April 18, at 11.26am
TODAY: Dry and bright.
TONIGHT: Patchy rain across Shetland extending into Orkney.
TOMORROW: Outbreaks of rain. Shetland misty.
DAYS 3-5: Becoming drier and brighter.
DAYS 6-10: Perhaps mostly dry and bright.
A bright start today then clouding over but remaining dry. SW’ly winds freshening a little. Outbreaks of rain, developing across Shetland, extending into Orkney later in the night.
Rain and cloud on Saturday, most persistent across Shetland where it will also turn misty. Some drier interludes for Orkney. Becoming generally drier and brighter by Sunday as fresh SW’ly winds become a lighter E’ly. Monday and Tuesday mainly dry with variable amounts of cloud. Light to moderate E’ly winds freshening later.
Possibly staying mainly dry and bright through the rest of next week with mostly moderate winds, these mainly E’ly in direction.
GENERAL SITUATION AND SYNOPSIS 06:00 UTC
As a ridge declines eastwards a SW’ly airflow will freshen a little today, ahead of an occluding frontal system pushed east by a depression running northeast through the Iceland region. The occlusion will be slow to clear the Northern Isles on Saturday
The SW’ly airflow is expected to ease over the weekend, as the weakening front is pushed away to the west as pressure builds over the north of Scotland and Northern Isles.
With high pressure persisting to the north while a shallow depression drifts west over the south of the UK, an E’ly airflow is expected by Monday. Present predictions suggest this synoptic situation – high pressure to the north with lower pressure to the south, may persist through next week maintaining a generally light E’ly airflow over the Northern Isles.
FORECAST FOR NEXT THREE DAYS
Confidence level: Weather type – medium/high. Timing – medium.
Temperatures rising to 9° or 10° Celsius by day, down to about 6° Celsius overnight.
FRIDAY 18th: After a bright start with sunny spells, though remaining dry, it will cloud over from the west during the afternoon. F3-4 SW’ly winds freshening F4-5. Some clearer spells across Orkney at first this evening before the cloud thickens and outbreaks of rain, developing across Shetland, extend south later in the night.
Sea State: Moderate to rough, with a 2 to 3 metre wind-swell. NW’ly at first, SW to S’ly later.
SATURDAY 19th: Rain and cloud will be slow to clear, the rain most persistent across Shetland with some drier interludes for Orkney. Becoming generally drier and brighter from the southeast during the evening as F4-5 SW’ly winds become a lighter F2-4 SE’ly.
Sea State: Moderate to rough, with a 2 to 3 metre S or SW’ly wind-swell turning SE to E’ly later.
SUNDAY 20th: Drier and brighter with light to moderate SE’ly winds.
Sea State: Moderate to slight in the east, with a 1 to 2 metre SE’ly wind-swell. Moderate to rough in the west, with a 2 to 3 metre SE’ly wind-swell.
Confidence level: Weather type – medium/low. Timing – low.
Temperatures 9° or 10° Celsius by day down to around 6° Celsius overnight.
MONDAY 21st: Mainly dry and bright. Light E’ly wind becoming moderate E to NE’ly.
Sea State: Slight to moderate becoming generally moderate, with a 1 to 2 metre E’ly wind-swell increasing to 2 metres.
TUESDAY 22nd: Dry and bright with a light E to NE’ly breeze veering E to SE’ly and increasing moderate.
Sea State: Perhaps mainly moderate, with a 2 metre E to NE’ly wind-swell.
WEDNESDAY 23rd – MONDAY 28th: Perhaps some showers early Wednesday otherwise mainly dry and bright with mostly moderate to fresh E to SE’ly winds. Possibly staying mainly dry and bright through the week and into the weekend with mostly light winds, these mainly E’ly in direction.
Sea State Wednesday: Possibly mostly moderate, with a mainly 2 metre SE to E’ly wind-swell.