The Met Office has warned that “intense” thunderstorms and heavy rain across much of England and Wales could cause travel disruption this week.
A band of heavy showers and thunderstorms is expected to move northwards on Wednesday morning, with warm and humid conditions bringing an increasing chance of heavy showers, thunderstorms and longer spells of rain.
Yellow warnings issued
A yellow warning for thunderstorms has been issued from 3am to 10pm on Wednesday across much of England, including London and the South East, the Midlands, East Anglia, and parts of the North West, South West, as well as eastern parts of Wales.
The Met Office warned that showers and thunderstorms on Wednesday afternoon “may be intense”, with 20-30mm of rain falling in less than an hour and 40-50mm possible in two to three hours in a few spots, leading to some surface water flooding.
There is a “small risk of flooding and disruption” from thunderstorms on Wednesday, including possible damage to some buildings from floodwater, lightning strikes or hail. Spray and sudden flooding could lead to difficult driving conditions and some road closures.
Forecast details
Met Office chief forecaster Steve Willington said: “As we move into Wednesday there is a growing risk of heavy rain and thunderstorms, with warm and humid air helping to trigger heavy showers and thunderstorms.”
“Some places could see significant amounts of rain falling in a short period of time, bringing the potential for localised flooding, travel disruption and frequent lightning.”
“On Thursday, slow-moving heavy and thundery rain may bring prolonged rainfall to some areas, increasing the risk of localised impacts. There remains some uncertainty around where the heaviest rain will fall, so it is important to keep up to date with the latest forecast and warnings.”
Large hail and frequent lightning are also possible before showers and thunderstorms drift northwards and ease during Wednesday evening.
Driving risks and further warnings
The RAC said risks to drivers from slippery roads from rainfall are “much greater right now as a result of the prolonged dry spell”. It added that oil, fuel and rubber deposits that have built up will now have been mixed together by light rain, instead of being washed away, which means drivers are at greater risk of skidding on greasy roads.
RAC road safety spokesman Rod Dennis said: “While slippery roads from rainfall is nothing new, the risks to drivers are much greater right now as a result of the prolonged dry spell.”
“Oil, fuel and rubber deposits that have built up over many weeks will now have been mixed together by the light rain, instead of being washed away, which means drivers are at greater risk of skidding on greasy roads. If heavier rain arrives, motorists may have to contend with the danger of flash floods in some areas.”
“For this reason, we urge drivers to reduce their speed in rainfall of any intensity and leave extra space behind the vehicle in front to reduce the chance of avoidable collisions.”
A further yellow warning for thunderstorms has been issued from 6am to 10pm on Thursday across large parts of England, including the Midlands, East Anglia, the North West, Yorkshire, the South West, as well as much of Wales. The weather service said there is a “small chance of fast-flowing or deep floodwater causing danger to life”.
The Met Office said 20-30mm of rain in three hours is “expected fairly widely” and up to 50mm in a 12-hour period can be expected in places. There is also a small chance that some places may see more than 50mm of rain in three hours and more than 75mm through 12 hours “especially over east facing high ground”. Lightning and hail of 1-2cm will also be hazards on Thursday.
The Met Office has advised people to “ensure moveable objects or temporary structures are well secured” before gusty winds arrive, including bins, garden furniture, trampolines, tents, gazebos, sheds and fences. Unsettled conditions may continue into Friday and the weekend, with further showers or longer spells of rain possible at times, alongside some drier and brighter periods.
