Welcome to the 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 28th October – Tuesday 2nd November
So the EC is suggesting that on Thursday rain and showers will move across the UK these will be heavy and persistent across the Western Isles along with brisk winds. Moving on to the Friday and low pressure dominates to the North West feeding rain and showers across the Western Isles along with brisk winds and some sunny spells. Into the Saturday low pressure to the North West of the UK and a shallow area of low pressure moves across the UK for us in the Western Isles we will see the feed of showers continuing across the islands with some sunny spells becoming drier and brighter into the evening. Moving into the Sunday and low pressure moves up the North sea feeding in rain and showers across the UK and further showers as low pressure moves across Shetland again more rain and showers for us in the Western Isles. Moving into Monday high pressure builds in briefly and a mostly fine dry and sunny start to the day but low pressure skirts South Eastwards bringing some rain and showers across the UK and some of these will feed into the Western Isles later in the day. Moving into the Tuesday and low pressure moves across the UK and behind it colder air will move in. For us in the Western Isles some rain and showers with sunny spells with brisk winds. Showers later in the day could turn wintry for a time.
GFS – Thursday 28th October – Saturday 6th November
So the GFS is suggesting that for the Thursday conditions will be mainly fine and dry with sunshine and cloud along with brisk winds to start the day for us in the Western Isles but rain increases later as low pressure moves across the UK. Into the Friday and multiple areas of low pressure swirl close to the UK to the North West. For us in the Western Isles we are going to see spells of rain heavy and persistent at times with increasing winds. On to the Saturday and low pressure to the South East of the UK will bring spells of heavy rain to parts of England and low pressure to the North West of Scotland will feed rain and showers across the Western Isles which will be heavy at times. Winds will be brisk. For the Sunday high pressure builds in and low pressure slowly clears away. We will see a wet start to the day in the Western Isles but this rain will clear away to sunshine and cloud with light winds. Moving into the Monday and low pressure swings in from the North West across the North of the UK and will feed in bands of rain across the Western Isles heavy at times with winds reaching gale force. For the Tuesday low pressure slowly sits close to the Western Isles feeding further rain and showers gradually drifting away. Gale force winds will tightly packed isobars with further rain and showers. The final four days of the time period and spells of rain and showers will feed across the Western isles wintry at times and heavy in places with brisk winds. A long way off as yet so plenty of uncertainty.
Thanks for reading any feedback is welcome. Featured photo from Louise Cook