Long range weather forecast for the Western Isles – 31st December 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 Monday 4th January until Wednesday 13th January.

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.

Monday 4th January

Solid model agreement regards next Monday with high pressure firmly in charge over Shetland and the cold airflow is cut off for now. We are going to see blue skies and sunshine with likely a hard frost. Blue skies and sunshine with light winds. Cold but beautiful.

Tuesday 5th January

Some model agreements again for next Tuesday. High pressure remains in play. We are going to see more in the way in cloud based on the GFS the EC gives us more in the way of sunshine. Light winds and frost likely once again. The GFS brings rainfall closer to the island for Tuesday hence the increased amount of cloud.

Wednesday 6th January

Model disagreement for next Wednesday. The GFS has multiple areas of low pressure on the deck. Low to our North West and would bring some rain and drizzle to the islands. Another low in the North Sea and one to the South East of England. The EC hangs onto High pressure across the Western Isles with dry conditions and sunny spells with a brisk wind coming in from the East.

Thursday 7th January

Good model agreement for next Thursday with a sinking area of low pressure moving down from the North will bring rain according to the GFS and Snow showers to the Western Isles according to the EC. Both shallow areas of low pressure so not much wind associated with this system.

Friday 8th January

The EC moves the above area of low pressure Southwards and brings more settled weather across the islands. With some sunshine and the odd scattered shower. This allows the doors to open from the East, with rain and snow piling into the East Coast of the UK. The GFS is a little slower to move the area of low pressure away from us. With sunshine and wintry showers.

Saturday 9th January

Some good model agreement that shows us returning to a more Northerly airflow with wintry showers and sunny spells. Brisk winds. A slack airflow like we have seen in the past week. Wintry showers across much of the UK.

10th,11th, 12th and 13th January

Now this is the really long range. So take it with a large amount of salt and is the silly range. So with the GFS suggests high pressure with a brisk airflow and no sign of any stormy January weather.

Thanks for reading any feedback is always welcomed.

Leave a Reply

Fill in your details below or click an icon to log in:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out /  Change )

Google photo

You are commenting using your Google account. Log Out /  Change )

Twitter picture

You are commenting using your Twitter account. Log Out /  Change )

Facebook photo

You are commenting using your Facebook account. Log Out /  Change )

Connecting to %s