Storm overflows spike tenfold as thunderstorms hit England and Wales

Wayne's own monitoring instruments flagged 201 storm overflow discharges across England and Wales at an hour when the normal reading is 21 — roughly ten times the expected level. Reporting from the ground suggests a plausible and immediate cause: a band of thunderstorms and heavy rain that has been moving across the two nations, following weeks of heat and drought. West Midlands Fire Service confirmed it was called to "significant flooding" in Birmingham, after a flood warning was issued for the Perry Barr area overnight due to rising river levels, according to [1]. Crews attended incidents around Curbar Road, Thornbridge Avenue and Haddon Road, supported by West Midlands Police and Birmingham City Council, which advised people to avoid walking, cycling or driving through flood water, according to [1]. The Met Office had two yellow thunderstorm warnings in force: one for London and the South East until 8am Thursday, and a larger one covering Wales and much of England from 5am to 10pm, according to [1]. The Environment Agency issued 22 flood alerts across the Midlands and South East, according to [1]. Forecaster Craig Snell said some areas could see more than 75mm of rain in 12 hours, with the South East warning zone facing 30-40mm and hail up to 1-2cm, according to [1]. A second source describes a closely related pattern of storm warnings a few days apart, covering broadly the same regions. According to [2], a yellow thunderstorm warning ran from 3am to 10pm on Wednesday 26 August across London, the South East, the Midlands, East Anglia, parts of the North West and South West, and large parts of Wales, with the Met Office forecasting 20-30mm of rain in under an hour and up to 50mm within two to three hours in the worst-hit spots — rainfall said to be capable of overwhelming drainage systems and causing surface water flooding, according to [2]. A further warning began at 6am Thursday 27 August, running to 10pm, with up to 50mm expected over 12 hours in some areas, according to [2]. Both sources note the storms followed an extended dry spell: [1] records that drought had been declared across nearly three-quarters of England and the whole of Wales, after five heatwaves and temperatures up to 38.1C in London; [2] similarly frames the storms as ending "weeks of heat and drought". That combination — parched ground and drainage systems, then intense short-burst rainfall — is consistent with the kind of sudden, widespread strain on sewer and drainage networks that would push storm overflow activity well above a normal baseline. The reporting material does not itself contain overflow discharge figures, so it cannot confirm the precise causal chain between these specific storms and the 201-event reading on Wayne's instruments. But the timing, geography and mechanism described — heavy, fast rainfall onto dry ground and stressed drainage across England and Wales — line up closely with what the monitors picked up. Nothing in the sources suggests a fault or unrelated signal; this looks like the water industry's overflow system doing what it's designed to do under exceptional and sudden rainfall. What to watch next: whether the Environment Agency or water companies publish overflow duration and volume data for this event, and whether the unsettled weather forecast through the bank holiday weekend triggers further spikes.