Long range weather forecast for the Western Isles – 18th March 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 Monday 22nd March until Saturday 31st March.

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.

Monday 22nd March

Some model agreement for next Monday with high pressure declining away. The EC suggests we are going to see a blustery day. Some rain and showers. These mainly on the light side. The GFS also sees the high pressure declining away with scattered showers. It will be a breezy. There would be some sunny spells and the UK sits in a slack airflow.

Tuesday 23rd March

Some model differences for next Tuesday. The EC brings in some light rain and showers throughout the day with a slack and breezy airflow across the Western Isles. The rain turning heavier into the evening as a band of rain pushes across the Western Isles. The GFS keeps things more settled with some sunny spells. Winds increasing as the day goes on with an area of low pressure moving to our North West during the day. A band of rain will move across the islands. This rain heavy at times.

Wednesday 24th March

Some model agreement for next Wednesday with rain and showers moving across the island according to the EC. Blustery winds and some sunny spells. The GFS moves the above mentioned low pressure system away from the Western Isles. A mild day with breezy conditions. Some decent spells of sunshine and winds coming from the and South West with occasional scattered showers.

Thursday 25th March

Some model differences for next Thursday. The EC has a brisk airflow across the Western isles. A day of rain and showers across the Western Isles. These will be heavy at times. Blustery winds. Staying on the mild side with the cloud dominating. High pressure sits to the South West of the UK with slack airflow further North. The GFS keeps conditions more settled across the UK with a band of rain moving into Ireland later in the day. For the Western Isles the rain is expected to stay dry with a day of sunshine and cloud. Brisk winds from the South and South West.

Friday 26th March

Some good solid model agreement for next Friday moves across the Western Isles. A band of heavy moves across the Western Isles. Winds will be brisk and then behind it the EC suggests we could see some wintry showers moving across the Islands. Squally showers with some sunny spells. The GFS suggests that it will be rain and showers. These heavy at times. An area of low pressure forms to the North West of the islands.

Saturday 27th March

Model differences for next Saturday so a long way off as yet. The EC suggests an area of low pressure system moves in that would bring some very heavy and persistent rain across the islands. Snow for mainland Scotland. Once this clears through bring rain and showers. The GFS keeps conditions with a day of sunshine and cloud with a few scattered showers. Brisk winds coming from the South and South West would keep conditions mild.

28th, 29th, 30th and 31st March

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 we are going to see further bands of heavy rain as multiple areas of low pressure move past the Western Isles. It would be windy at times.

Thanks for reading any feedback is always welcomed.

Featured photo is West Beach by Claire Conner

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