Mynachdy (Cardiff) weather

Headline:

Isolated thunderstorms clearing, then cooler and mainly dry this weekend.

This Evening and Tonight:

The chance of an isolated heavy shower or thunderstorm in eastern areas at first this evening, then generally dry overnight with clear spells. Light drizzly showers may arrive in Anglesey and Gwynedd later. Remaining rather warm and humid for some. Minimum temperature 13 °C.

Saturday:

Any isolated showers in the west clearing to leave a dry day with sunny periods. Generally feeling somewhat fresher in the northerly breeze but locally very warm in the south. Maximum temperature 26 °C.

Outlook for Sunday to Tuesday:

Mostly dry on Sunday and Monday with sunny spells. Breezier by Tuesday with the chance of some welcome rain or showers for some. Still warm with temperatures mostly above average.

The first few days of this period are likely to be rather changeable, with many parts of the UK seeing showers or perhaps some longer spells of rain. Within this broad pattern, there is potential for a low pressure system to develop just to the west or possibly over the UK, which would bring the possibility more widespread rain and perhaps strong winds. By the latter part of August, there are signals for high pressure to become rather more dominant again, with more in the way of dry weather developing once more, especially towards parts of the north and west. Temperatures are more likely to be above normal than below overall, though the possibility of widespread or exceptional heat is perhaps a little lower than in recent weeks.

As we move into the start of meteorological autumn, signals for the prevailing weather patterns affecting the UK are weak, thus something close to the climatological norm is the current preferred story. This means a broad northwest-southeast split in conditions, with the high becoming centred further to the south than in the latter part of August and with more changeable conditions developing towards the north and northwest. Meanwhile, drier, more settled weather is slightly more likely towards the south and east. Temperatures are again likely to be above average overall, with the potential for late season hot spells or heatwaves, especially in the south.