A dry and warm week ahead but low pressure is heading our way for the weekend…but it might also cause it to become warmer.
Decided to take advantage of the bank holiday to do the forecast with the morning models, as I’ve had too much fun this weekend to expect to be awake by time the evening models are published.
Thanks to Louise for the photograph.
Today will be rather cloudy, though a few sunny breaks particularly later in the day. A very, very small chance of a light shower and it will reach around 22’C. Some clear spells overnight, some cloud too, down to around 13’C.
The general picture by Tuesday sees a fairly strong build of high pressure to the north of the UK, a hint of low pressure over the continent, and a warmish easterly flow for us.
Tuesday starts with hazy sunshine. Quite a lot of cloud will bubble up and spread west, but there will be some sunny spells at times – more cloud than sunshine overall. One or two showers may develop, say a 20% chance of catching one, they should be fairly light. Warm, 23’C in a notable easterly breeze. Clear spells overnight, down to around 13’C.
Wednesday starts rather sunny and there will be more sunshine than the previous two days. Still some cloud bubbling up, but overall throughout the day there should be a bit more sunshine than cloud. Very warm, 24’C, and still that easterly breeze. Mostly clear skies overnight and temperatures down to around 13’C once more.
Thursday remains similar, some good sunny spells, some fair-weather cloud bubbling up and very warm once more, 24’C, maybe 25’C. And still the notable easterly breeze. Mostly clear skies overnight, down to around 12’C.
And then things get more interesting. The high pressure block to our north effectively stops the jetstream and forces it south, towards the UK.
This sends low pressure towards the UK, which also interacts a bit with the weak low pressure over the continent, and we end up with low pressure close to the UK by Friday.
Some weather models take the low pressure system and sit it over the UK – which would mean temperatures in the range of 17’C to 21’C, and frequent heavy showers, or general heavy rain.
But some weather models, take it a little to our west – which would still result in some heavy/very heavy showers and possibly some general heavy/very heavy rain, but would also increase temperatures (when not raining) to the range of 22’C to 28’C – along with more humidity and a reasonable chance of some thunder. I think this outcome is slightly more likely.
Every day from here is subject to high amounts of uncertainty – until we know where the low forms.
So Friday, should broadly still be a reasonable day, some sunny spells, some cloud, likely very warm and possibly humid. 25’C, give or take. Around a 20% chance of a heavy shower. Probably fairly cloudy overnight, a small chance of a heavy shower and down to around 15’C.
Saturday looks to have a higher chance of some heavy/very heavy showers, say a 50% chance or so, a small chance of them being thundery. Probably some hazy sunshine with temperatures more likely in the range of 24’C to 28’C – but don’t be shocked if lower, as it will depend on positioning of the low pressure which we don’t yet know.
Sunday has a higher chance of heavy/very heavy showers, say a 70% chance – there could instead be a band of general heavy rain moving up from the south. A small chance of thunder, and temperatures broadly in the range of 22’C to 28’C, depending on showers/rain activity, and the position of the low pressure. Vague, I know, but it is what it is.
It’s pretty pointless attempting details for next week, so I won’t, but low pressure should remain on the scene. Assuming it did set up to the west of us, then expect more very warm/quite hot conditions, some humidity, and some heavy/very heavy showers – and probably some general heavy rain at times. But also some hazy sunshine at other times. Small chances of thunder mixed in.
Not sure where we go from there – I would suggest that it will stay unsettled through the middle of September, that is the form horse, but it now looks fairly likely that we’ll have our first major Atlantic hurricane of the season (I think…unless I’ve missed one) towards the east coast of the USA, so maybe that will have an effect on our weather patterns…maybe it will push the Azores high east and settle things down, or maybe it will invigorate the jetstream and bring wind and rain our way…just conjecture, I have no idea yet.
Next update will be on Thursday evening. Autumn forecast will probably be Friday evening or Saturday morning…depending on…well…life.