WEATHER OUTLOOK FOR SHETLAND
Friday, 13 July 2012 at 11:10
TODAY: DRY, BRIGHT AND COOL
TONIGHT: MAINLY DRY
TOMORROW: MOSTLY DRY, COOL, BRIGHT
DAYS 3-5: SOME RAIN LATER
DAYS 6-10: CHANGEABLE, PERHAPS MILDER
A fine though rather cloudy day across the Northern Isles. Most places staying dry, with sunshine for some. A cool NW’ly breeze. A dry night for many, though still a few showers around. Moderate N’ly winds.
Saturday bright with still the risk of a few showers. Moderate to light NW’ly winds. Sunday again bright with scattered showers. Freshening W’ly winds with some rain overnight.
Cloudy with patchy rain on Monday, this lingering over Orkney as Shetland turns brighter. Moderate or fresh W’ly winds. A brighter and drier day generally on Tuesday with mostly light winds.
The middle part of next week perhaps bright and cool with scattered showers and light NW’ly winds. Then becoming milder with some rain or showers and moderate or fresh SW to W’ly winds.
GENERAL SITUATION AND SYNOPSIS 06:00 UTC
With pressure low across Scandinavia and a small anticyclone over Iceland a cool N’ly airflow persists over northeast Scotland. The airflow will ease overnight as pressure continues to build slowly across the Northern Isles.
Little change is expected at first but later in the weekend the high over Iceland is expected to have moved south into mid-Atlantic, with a depression over the Norwegian Sea then pushing a front south towards Shetland.
During Monday a small low centre is forecast to swing east past the north of Shetland. As the low moves away east and pressure builds to the west, a light NW’ly airflow will cover the Northern Isles midweek.
The present prognosis suggests that later next week, as Atlantic high pressure declines southwards, a shallow depression will move slowly east over Iceland.
FORECAST FOR NEXT THREE DAYS
Confidence level: Weather type – medium/high. Timing – medium.
Temperatures rising to around 12° Celsius by day, with an overnight low of about 8° Celsius.
FRIDAY 13th: Though there will be generally large amounts of cloud it will be bright with some sunny spells. There are one or two showers around but many places will remain dry. A few more showers may develop during the afternoon, these mostly affecting Yell and Unst in Shetland and Hoy in Orkney. A few showers continuing through this evening and into the night, these mainly affecting the north of Shetland while elsewhere it remains mainly dry. F4 N’ly winds.
Sea State: Mostly moderate to slight, with a 1 to 2 metre N’ly wind-swell turning NW’ly later.
SATURDAY 14th: Bright with sunny spells but still the risk of a few showers, these mostly across west of Orkney and Shetland. F3-4 NW’ly winds.
Sea State: Mostly moderate to slight, with a 1 to 2 metre NW’ly wind-swell.
SUNDAY 15th: Bright with scattered showers these perhaps a little more widespread later in the day as moderate F3 W’ly winds increase F4-5. Some rain overnight with SW to W’ly winds increasing F5-6.
Sea State: Moderate to slight becoming moderate to rough later, with a 1 to 2 metre W’ly wind-swell increasing 2 to 3 metres by evening.
Confidence level: Weather type – medium. Timing – medium/low.
Temperatures 13° or 14° Celsius by day, with overnight lows about 9° Celsius.
MONDAY 16th: Cloudy with patchy rain, this lingering over Orkney as Shetland turns drier and brighter. Moderate or fresh W’ly winds.
Sea State: Possibly moderate to rough, with a 2 to 3 metre W or NW’ly wind-swell.
TUESDAY 17th: A brighter and drier day generally with mostly light winds.
Sea State: Perhaps mainly slight to moderate, with a 1 to 2 metre NW’ly wind-swell.
WEDNESDAY 18th – MONDAY 23rd: Perhaps bright and cool at first with showers and light N or NW’ly winds. By the weekend becoming milder and breezier with some rain or showers and moderate or fresh SW to W’ly winds.
Sea State on Wednesday: Possibly mainly slight to moderate, with a 1 to 2 metre N’ly wind-swell.