Welcome to 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 18th November to Tuesday 23rd November
So the EC is suggesting high pressure across the South of the UK for Thursday with brisk winds across Northern Scotland with a band of heavy rain moving across the islands. Once this clears sunshine and showers for us in the Western Isles. Into Friday and more of the same with rain and showers moving across the islands with brisk winds. Into Saturday a change with high pressure to the West and East with a cold airflow coming down from the North with rain, wintry sleet and snow showers. Moving onto the Monday high pressure builds in from the West but a band of rain slides across the Western Isles before further showers move across the island later. Into Tuesday high pressure sits to the West with further spells of rain but becoming drier and brighter later in the day. Moving on to the Wednesday high pressure across the UK but yet again further rain and showers across the Western Isles. But winds will be lighter.
GFS – Thursday 18th November to Saturday 28th November
So the GFS is suggesting that a strong airflow across the UK with further spells of rain for us in the Western Isles on Thursday. Moving on to the Friday high pressure to the South and again further spells of rain moving across the Western Isles along with brisk winds. For the Saturday a wet start to the day for the Western Isles with high pressure building behind becoming drier and brighter for us in the Western Isles. Both the Sunday and Monday high pressure builds across the UK with sunshine and cloud with lighter winds. Occasional spells of light rain. Tuesday another high pressure dominating day with sunshine and cloud along with light winds. Finally, the Wednesday and areas of low pressure moving across Northern Scotland will feed rain and showers across the Western Isles becoming heavy for a time. The final few days of the time period wintry showers with a chance of snow showers for Thursday and Friday. A long way off as yet but worth keeping an eye on yet for a colder end to the month.
Thanks for reading any feedback is welcome. Our Featured photo Harris by Colin Cameron