After a mostly fine and increasingly warm week, the weather is on the change, culminating in a cooler, less settled spell as we end the week and move through the weekend. For today though. it's still warm but there will be (in fact there already are) some sharp, thundery showers around.
The change is coming about as high pressure retreats and low pressure starts to take control, with the beginnings of that destabilising the atmosphere today.
It's into tomorrow that an Atlantic low swings into Ireland, and from there it's not going to be going very far, very quickly with it and then a secondary low sliding up beneath it will probably be around, generally drifting around close to Ireland and the western side of the UK right into the start of July. As you may imagine, that's not going to be conducive to settled weather, with all parts likely to see rain at times over the coming week or so, but with western parts seeing the most frequent, often showery rain.
The ECMWF map below shows the rain amounts across the next 5 days, and illustrates the pattern quite well, with western parts seeing the highest totals, but nowhere staying entirely dry.
At shorter range, today has already seen the showers get going early on in the southeast of England, and that initial batch will tend to drift northwest through the day. At the same times scattered additional downpours are likely to break out across other parts of central and western England, along with Wales. In terms of thunderstorms, it's perhaps through Wales and western England where these are most likely, but some electrical activity is possibly in amongst any of the showers, with hail and gusting winds in amongst the liveliest ones too.
Away from the showers, it's going to be another warm day with good sunny spells, with maximum temperatures widely rising up into the low or mid-twenties - perhaps even towards the high twenties in eastern England.
Into tomorrow (Friday), the process of less settled weather will accelerate. There'll be two things to keep an eye on - a front moving up from the southwest during the day, bringing showery rain and cooler conditions with it. The cloud ahead of that will keep temperatures a bit lower in the west tomorrow, but further east with more sunshine likely, temperatures are again expected to rise up into the mid-twenties and that may trigger some homegrown downpours and thunderstorms.
The front introducing fresher and cooler conditions will move through during the latter part of Friday and overnight to leave all parts with fresher westerly winds on Saturday. There'll still be sunny spells around, and it'll feel warm enough in them, but with highs into the teens or low-twenties at best it will feel cooler. There'll also be a scattering of showers - these starting in the west and blowing east through the day. For more details on the weekend, take a look at Jo's weekend weather forecast.