A yellow 'be aware' weather warning for thunderstorms has been issued by the Met Office for parts of Wales on Friday.
The warning is valid from 11am until 8pm and covers southern parts of the country, with hail, lightning and thunder likely during this time.
We could also see some rather difficult driving conditions on the roads today in the thunderstorms and winds will strengthen, with gusts of up to 40mph expected around western coasts.
Power cuts and damage to buildings from lightning strikes is also possible.
Rainfall recorded in St Athan in the last 24 hours
There has already been a lot of wet weather over the last 24 hours. St Athan recorded 61.6mm of rain between 8am on Thursday and 8am on Friday morning.
The average monthly rainfall total for the South Glamorgan area in August is 90.6mm - with St Athan receiving almost two thirds of that total in one day alone yesterday.
This week has seen some rather unsettled weather, with low pressure systems dominating, bringing with it some wet and windy conditions.
Storm Francis caused damage and travel disruption earlier this week due to flash flooding and fallen trees.
Lake Vyrnwy, Powys recorded wind gusts of 75mph - the windiest August day on record. The last time these gusts were equalled was in Milford Haven in 1979.
Gusts recorded at Lake Vyrnwy this week
High pressure will start to build and dominate our weather story as we head into the weekend, with things turning much drier and brighter with some sunny spells and the winds easing.
However, it will also feel much cooler this bank holiday weekend. Last year the mercury hit 28°C in Cardiff, but this year highs of just 18°C have been forecast.
The northerly airflow over the weekend will mean that temperatures will be on the cooler side. At this time of the year, temperatures should really be around 18°C across Wales, however, some spots will struggle to get above 15°C.