Machynlleth (Powys) weather

Headline:

Turning cooler for the next few days. Outbreaks of rain.

This Evening and Tonight:

Cloud thick enough for a few showers this evening, then rain moves in from the west. Mostly light but turning showery into the early hours with a few showers persisting till dawn. Feeling fresher and less humid. Minimum temperature 12 °C.

Wednesday:

The odd isolated, possibly heavy, shower remains through the day, but most places staying dry with sunny spells. Temperatures around, or just below average for the time of year. Maximum temperature 22 °C.

Outlook for Thursday to Saturday:

A northerly wind develops for the next few days, allowing temperatures to drop below average. Thunder showers for Thursday and Friday, but brighter and drier for Saturday.

This period is likely to start largely dry and settled across the UK, as a ridge of high pressure sets in. A few showers are likely in the far north and possibly the far southeast though. Conditions look like turning increasingly unsettled through next week, as low pressure gradually becomes dominant, squeezing the ridge off to the northeast. Most places are likely to see some rain or showers, particularly during the second half of next week, and these may be heavy with a risk of hail and thunder. It may become breezy if not windy at times too. Temperatures are likely to be near or a little below normal overall, with some chilly nights at first, but brief warm, humid spells are possible at times, especially in the south.

As we move into the start of meteorological autumn, it looks like it will start rather unsettled. However, signals for the prevailing weather patterns affecting the UK soon become weak, with something close to the climatological norm becoming most likely. This means a broad northwest-southeast split in conditions, with higher pressure becoming centred close to the south of the UK and lower pressure towards the north or northwest. The north and northwest will probably see the lion's share of the rain and any strong winds, whilst the south and southeast will probably see the driest and sunniest weather. Temperatures are likely to be a little above average overall. There is a chance that late season hot spells or heatwaves develop, especially in the south.