Models trend towards an unsettled first half of July, with average temperatures

After what has been a dry and record-breaking warm June for many, the first half of July is looking quite different, with the jet stream and low pressure in charge, with the flow off the Atlantic bringing changeable conditions of spells of rain or showers at times along with some drier and sunnier spells. It will be breezier or windy at times too, good for producing electricity from wind power. Maybe not so much for solar power. Temperatures look to be slightly below average to begin July, more especially in the west, but there are signs that temperatures will recover to average or above by weekend of the 8th/9th.

The weather today has turned cooler and fresher for all behind a cold front that cleared SE England this morning, clearing away the very warm and muggy air from southern and eastern areas. However, muggy air will return tomorrow, as warm front moves in from the west off the Atlantic – introducing a ‘warm sector’, before another cold front moves in early Saturday – bringing back cooler and fresher air in a brisk west to northwesterly flow over the weekend, with showers or longer spells of rain. Quite a different feel to last weekend, when we saw 32.2C reached in Lincolnshire last Sunday.

Low pressure to the north towards Iceland will be in charge of the weather for the rest of this week and through the weekend. Friday is looking mostly cloudy with outbreaks of mostly light rain spreading from the west with more humid air returning with the warm sector, some heavier burst of rain across Scotland. However, a cold front clearing east Saturday night will bring clearer and fresher conditions for the weekend for many, with many staying mostly dry with some sunshine, but there will be showers at times, more especially for northern and western areas. On Saturday, a low looks to form to the NW of Scotland and deepen as it tracks east over the Northern Isles – this looks to bring a spell of wet and windy weather across northern Scotland from Saturday night and through Sunday. Temperatures around average over the weekend in stark contrast to last weekend, when we saw temperatures well-above average.

Humid air returns on Friday, but will be replaced by cooler and fresher conditions from the Atlantic on Saturday:

Low pressure looks to remain in control as we head into early July, certainly through much of next week, with the polar jet stream flowing across the UK. This means a continuation of changeable conditions, with spells of rain or showers at times, but also some drier and sunnier interludes too. Often breezy or windy, especially around coasts.

Low pressure close to the north next week, looking at 5 day EPS mean for surface pressure

Temperatures could be cooler than average from Sunday and through early next week (when’s the last time that happened?!) – more especially in the west, thanks to the flow turning northwesterly, perhaps northerly across northern areas. This is thanks to the upper trough close to the north to end this week tending to shift east over Scandinavia by early next week - allowing a ridge to build to the west.

But signs are from ensemble guidance that the upper low may reposition back to the northwest or west of the UK, which would support a warmer southwesterly flow from around the following weekend (8/9th July). So after a cool first half of next week, we may see temperatures recover to above average by the following weekend.

But the 00z EPS clusters show strong support for an upper low to be close to the UK all the way out towards the middle of July. So we may see changeable, sometimes unsettled conditions, dominate through the first half of July, with spells of rain or showers at times, but also some drier sunnier spells.

This will be in contrast to last summer – where we saw strong high pressure dominate through much of July, bringing some very high temperatures and very little rain.