The Met Office has issued a Yellow Warning of Rain:
Issued at: 1058 on Tue 15 Sep 2015
Valid from: 0800 on Wed 16 Sep 2015
Valid to: 0900 on Thu 17 Sep 2015
Persistent and at times heavy rain is expected to spread from south to north during Wednesday, this affecting much of England and Wales. Some heavy and thundery showers could also develop across East Anglia and southeast England during the afternoon. Strong and gusty winds are also expected, with gales in exposure.
Rain should ease from the southwest later on Wednesday, but will persist across the north of the warning area into Thursday.
Some localised flooding is possible from fast responding water courses and standing water, this perhaps disrupting travel. Lightning associated with the afternoon showers across East Anglia and SE England will be an additional hazard.
Chief Forecasters Assessment:
A complex area of low pressure is expected to deepen over the Bay of Biscay later today and into Wednesday, before pushing north towards the UK. Rain will arrive into southern areas Wednesday morning, before spreading to the rest of the warning area through Wednesday afternoon and into Thursday. Rain should ease from the south during the day, though some heavy and thundery showers may develop across the southeast and East Anglia through the afternoon and evening.
Most parts of the warning area should see 15-30 mm of rain, however some places could see as much as 40-70 mm. Furthermore, thunderstorms developing across the southeast and East Anglia Wednesday afternoon have the potential to generate 15-25 mm of rain in a few hours.
This is a very complex development, and uncertainty in timings and areas most at risk is large. As such this warning will be updated as confidence in developments increases.