Warm air from the south at the weekend but the threat of Atlantic rain looms for Sunday

There will be warmth this weekend in a southerly flow. Not necessarily summer heat but still feeling warm in the sunshine until the arrival of rain from the west. There will be a spell of fine, settled and sunny weather without the heavy showers of midweek. Temperatures will rise into the twenties Celsius, potentially past 25C depending on the progress of the incoming Atlantic system. 

Friday looks fine for most with just a scattering of showers. Northwest England looks prone, with southwest England also catching a few. There will be sunny spells by day but overnight, with clear skies for Britain, temperatures will dip away, down into single figures for rural areas. 

High pressure will move over southern Britain on Friday and settle over central Europe. There will be light winds, a lot of dry weather and even sunshine this weekend for mainland Europe, although some areas will see low cloud. Scandinavia and Poland will experience more showery conditions with a low pressure swirling over the Baltic Sea. 

Although there should be a lot of fine weather on Saturday, the Atlantic system will begin to throw a few showers over Northern Ireland and western Scotland in the morning, perhaps some heavier bursts over the northwestern half of Scotland during the afternoon. 

There is a balance, the high pressure acting as a shield over Europe and slowing anything coming from the Atlantic. A strengthening jet will help develop the low pressure out west, it will deepen rapidly over the weekend but there is some disagreement about how far the frontal rain will reach across the UK on Sunday. The UKV model is more progressive, but the ECM and GFS seem to allow for another day of fair weather for parts of England, even SE Scotland and potential warmth. This might extend through eastern Britain. The upper temperatures for SE England could reach 25 to 28C if the cloud and rain are held away and the ECM model allows for more of Britain to stay warm and fine on Sunday. Further west, there will be more cloud and outbreaks of rain. Sunday looks blustery for northern areas of the UK and western coasts of Britain with a wind from the south or southeast. 

Looking around the UK 

Belfast should be bright on Saturday, but there will be a fair amount of cloud over Northern Ireland. There is a risk of a shower in the morning but these fade from County Down by lunchtime. Sunday brings the highest risk of rain across Northern Ireland. The air flow will have some warmth, but there will be outbreaks of rain and the brisk breeze without much sunshine. There could be some heavy downpours before a clearance from the southwest behind the cold front with lighter winds and possibly some evening sunshine. It all depends on the timing of the frontal bands.

Edinburgh will have a fine Saturday with bright or sunny spells. It should stay dry in a light southerly breeze. Temperatures will reach 20C and it will feel pleasantly warm. There is some uncertainty for Sunday, will the rain reach across the Central Belt? Even if it does, Edinburgh could find itself sheltered as other parts of Scotland see hefty downpours. The air will still be warm from the south but temperatures will dip in any passing rain. 

Birmingham and London look fine with sunny spells. Temperatures will be in the low 20sC.  Sunday could see more cloud but should be dry. There is a risk of a shower for the West Midlands, but a low risk for any particular spot.  Temperatures will be 21C for Birmingham and 22 to 27C for London, depending on the amount of sunshine. 

Cardiff should have a fine Saturday with bright or sunny spells and temperatures around 23C. Sunday has a higher chance of rain with temperatures around 20C. 

The airflow is warm for the weekend but it is just this complication of the incoming frontal rain from the west with more cloud. Will it mostly move over Northern Ireland and Scotland, will it slow down and not bring much to parts of Britain away from western counties?  Have a look at the Netweather radar on Sunday.