Long range weather forecast for the Western Isles – 26th September 2020.

Good afternoon and welcome to our long range forecast. This is posted either once or twice a week covering from 4 days ahead to 10 days ahead. In this update coving from Wednesday 30th September until Friday 9th October.

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 which is based in Reading and the GFS 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.

Wednesday 30th September

There is strong model agreement of heavy overnight rain as we go Tuesday into Wednesday. Winds gusting 30 to 40 mph. Milder weather conditions. Low pressure will move to our North West. The low pressure will be near iceland and its associated fronts will bring the fronts. Sunshine and cloud with a few showers during Wednesday.

Thursday 1st October

Big model differences for Thursday. The GFS has low pressure bring rain and stronger winds for the South of the UK. Showers and breezy conditions for us in the Western Isles. The EC has two areas of low pressure. One centered close to us and one over Ireland both these will bring rain and stronger winds. But for us not expected to be stronger then 40 mph.

Friday 2nd October

Again model differences with the EC suggesting one area of low pressure over South East England. With mainly light rain for us and not much wind. The GFS has two areas of low pressure one over South East England one for the East Coast of Scotland. This would bring us more in the way of wind and rain but nothing significant. Northerly and North Westerly winds.

Saturday 3rd October

Both models suggest areas of low pressure over Scotland with the EC deeper and showing stronger winds and rain. A less deep area of low pressure with the GFS but would also bring winds and rain. This is a long way off as yet but worth keeping an eye on its slowly getting to that time of year but things will change between now and then.

Sunday 4th October.

The GFS settles things down somewhat with some rain but lighter winds. Again a long way off. The EC shows the area of low pressure staying deeper with strong winds and further spells of rain before this eventually clears away.

Monday 5th October

Both GFS and EC show areas of low pressure moving away with winds decreasing with more settled conditions. Some spells of rain. Fairly cool.

6th,7th,8th and 9th October

This is well into the really silly timeframe. EC doesn’t even go this far out so just the solo use of the GFS. Hints of things finally settling down for a few days with some chilly days. Before more rain moves in towards the end of the timeframe.

It looks set to be another unsettled spell coming up. Any feedback is welcome.

I hope you have enjoyed.

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