Wednesday, May 27, 2015
TODAY: Showery outbreaks of rain. Becoming drier and brighter. Breezy.
TONIGHT: Showers. Chance of rain for Shetland.
TOMORROW: Bright with occasionally heavy showers.
DAYS 3-5. Bright on Friday with showers, occasionally heavy. Breezy. Becoming mainly dry on Saturday with easing winds. Rain and wind for a time on Sunday.
DAYS 6-10: Changeable and breezy, but possibly drier and brighter with light winds midweek.
A mostly cloudy start today with outbreaks of rain, but gradually turning brighter with some drier, brighter spells by the afternoon. Moderate to fresh SW’ly winds. Cloudy with some showers tonight, with the risk of more persistent rain for Shetland. Winds becoming NW’ly, mainly moderate in strength.
Some rain at first for Shetland otherwise Thursday bright with scattered occasionally heavy and possibly thundery showers, Moderate to fresh northwest winds. Friday bright with sunny spells and fewer showers, though still the chance of the odd heavier one. Easing winds.
The weekend mainly dry and bright with moderate W’ly winds falling light for a time. Strengthening S’ly winds bringing rain on Sunday. The following week possibly starting showery but becoming drier and brighter as fresh SW’ly winds ease.
GENERAL SITUATION AND SYNOPSIS 06:00 UTC
Pressure is high to the southwest of the British Isles and low over and to the east of Iceland. Fronts will be carried past the Northern Isles in a fresh to strong SW’ly airflow. An easing W to NW’ly airflow will follow overnight and through Thursday as the filling Icelandic depression drifts down over Faeroe towards Shetland.
A NW’ly airflow will freshen on Friday as low pressure moves into Scandinavia and pressure builds from the west. A ridge is expected to build southeast over the Northern Isles on Saturday, with a freshening S to SE’ly developing later on Sunday as the ridge declines and fronts approach from the west.
The forecast for the first part of the following week suggests an easing SW’ly airflow as filling low pressure to the northwest of Scotland moves away.
FORECAST FOR NEXT THREE DAYS
Daytime highs of 10° or 11° Celsius, perhaps 12° Celsius for Kirkwall and 9° Celsius on and near exposed western coasts. Overnight lows around 6° Celsius.
WEDNESDAY 27th: Starting mostly cloudy with outbreaks of rain, heavy at times. However, it will gradually turn brighter through the late morning and into the afternoon with some drier, brighter spells. F4-5 SW’ly winds, occasionally F5-6 across Shetland. Some sunshine and occasional showers this evening. The cloud is likely to thicken overnight, with the risk of more persistent rain in Shetland. Winds becoming NW’ly, mainly around a F4 strength.
Sea State: Moderate to rough, with a 2 to 4 metre SW’ly wind-swell. Highest in the west.
THURSDAY 28th: Any rain remaining in Shetland soon clearing, then brighter with sunny spells and showers, occasionally heavy with the risk of the odd rumble of thunder. F4-5 W to NW’ly winds.
Sea State: Mostly moderate, with a 2 metre W’ly wind-swell.
FRIDAY 29th: Bright with sunny spells and showers, still the chance of a heavier one. F4-5 NW’ly winds.
Sea State: Mostly moderate, with a 2 metre NW’ly wind-swell.
Temperatures 10° to 12° Celsius by day, down to around 6° Celsius overnight.
SATURDAY 30th: A rather cloudy start with showers, but becoming mainly dry and bright as moderate NW’ly winds become light W’ly.
Sea State: Slight to moderate, with a 1 to 2 metre NW’ly wind-swell. Highest in the west.
SUNDAY 31st: Starting mainly dry and bright with light winds then S to SE’ly winds strengthening with rain reaching Orkney around midday and Shetland during the afternoon. The rain clearing to showers later as winds veer fresh to strong SW to W’ly.
Sea State: Perhaps slight to moderate, with a 1 to 2 metre S to SE’ly wind-swell.
MONDAY 1st – SATURDAY 6th: The week perhaps starting and ending with some rain or showers and fresh SW’ly winds, with a drier and brighter interlude with lighter winds midweek.
Sea State Monday: Possibly moderate to rough, with a 2 to 3 metre SW to W’ly wind-swell.