Welcome to the our long range forecast for the Western Isles. This is our twice weekly update covering up to two ahead. We look at trends and patterns. Usually posted on a Thursday and Sunday.
Please note there is not a lot of accuracy for this kind of time frame. Anything beyond 4/5 days out becomes really difficult and subject to change so we will be looking at trends. Mainly take with a large vat of salt. We will be using the main two computer models for this. The ECMWF ( European Centre for medium range weather forecasts) which is based in Reading and the GFS (Global forecasting system) which is the American based global model.
This comes from the GFS 06z run and ECMWF 00Z run. I will refer to EC to save on typing.
EC – Thursday 14th October – Tuesday 19th October
So the EC is suggesting for Thursday that rain will move down from the North bringing rain and showers to the Western Isles it would be cooler. Brisk winds with spells of rain for us in the Western Isles. This would clear away as the goes on to give us a mainly fine and dry end to the day with plenty of cloud. Into the Friday high pressure slides across us moving South East. We would see fine and dry weather across the Western Isles. However winds would become brisk with rain and showers moving in later in the day. Into the Saturday and low pressure forms near Ireland and would move Northwards and push across the Western Isles gives us blustery winds and heavy rain. For the Sunday the area of low pressure clears away but we will see spells of further rain and showers moving across the islands heavy at times along with brisk winds. Into the Monday and Tuesday and it’s more of the same further rounds of rain will move across the Western isles. Heavy at times with brisk winds. Several areas of low pressure will move past to the North West.
GFS – Thursday 14th October – Saturday 23rd October
The GFS is suggesting for Thursday that it will follow the same pattern as the EC with a high pressure dominate start to the day but rain and showers will spread down from the North as the day goes on. This will become heavy at times. Into the Friday and the rain proves slow to clear but this will clear away as high pressure slides down South East across the UK resulting in fine dry and settled conditions with light winds. For the Saturday and the high pressure slides away and rain and showers will move across the Western isles bringing spells of rain which will be heavy at times. Into the Sunday and a day of rain and showers will move across the Western Isles which again would be heavy at times with gale force winds possible with tightening isobars. For the Monday an area of low pressure will sit to the far North West and bands of rain and showers along with brisk winds will move across the Western Isles. Into the Tuesday and area of low pressure moves across Ireland. For us in the Western Isles an wet start will see a colder airstream move across the North of the UK with sunshine and cloud to end the day. Now for the final 4 days of the time period. The Wednesday and Thursday there is some hints of some wintry conditions with some sleet and snow showers. A long way off as yet and the previous model run does not show this. Worth keeping an eye on. But things are looking colder. The Friday and Saturday high pressure builds back in with sunshine and cloud along with light winds.
Thanks for reading any feedback is welcome. Featured photo taken by Ronan Dugan of Uig sands