Long range weather forecast for the Western Isles – 17th January 2021

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 Thursday 21st January until Saturday 30th 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.

Thursday 21st January

So some good model agreement for next Thursday with both the GFS and EC with low pressure in the North Sea. Rain and wintry showers with risk of sleet and snow showers across the Western Isles. There is some risk we could see a covering of snow in places. But a lot of uncertainty with that as yet. Winds will be coming down from the North and North West gusting to 40 mph.

Friday 22nd January

Some slight model disagreements for next Friday with the EC bringing snow showers and a risk of snow across the islands. The low pressure in the North Sea would move North of Shetland and keep the cold airflow from the North covering the islands. We are going to see blustery winds. The GFS will move the low pressure over Europe and we will see still a cold airflow across the islands with wintry showers and blustery winds coming in from the North West.

Saturday 23rd January

Again staying cold the EC keeps the low pressure to the North of Shetland with sleet and snow showers moving across the islands with risk of frost and ice. We could see some snow falling to lower level and dusting in places. Further blustery winds. The GFS on the other hand sinks a low pressure to the North of the islands and it would bring spells of snow to the islands. Lot of uncertainty about this and it will change between now and then but if it did happen we could see snow for many places to low levels.

Sunday 24th January

Some good model agreement with next Sunday as the both the models have a low pressure system over Scotland. The EC moves the low over the Western Isles. Rain and wintry showers and once this clears away becoming drier and brighter. The GFS has the low pressure over eastern Scotland with wintry showers and rain for most of the day with lighter winds.

Monday 25th January

Some good model agreement again between the EC and the GFS with some rain and showers in the morning but weather will become drier and brighter with sunshine and cloud. Winds will be light. Low pressure moves to the West of us. The EC has the low to the South West of Ireland and the GFS has the low more to the West of the UK and expected to bring rain into the UK.

Tuesday 26th January

Model disagreements with this date. The EC has high pressure across the Western Isles with fine dry weather. Sunshine and cloud. Along with lighter winds. The GFS brings in a band of rain with the area of low pressure mentioned above. This will bring spells of rain and once again the risk of snow. A long way off as yet.

27th,28th,29th and 30th 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 it suggests that will see mainly dry and settled conditions across the Islands. Low pressure systems move across the Southern half of the UK.

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