Potential for some heavy rain tonight and tomorrow

Message from the Met Office Advisor - Thames Valley & Surrey

Good morning,There is the potential for some heavy rain tonight and tomorrow

Headline:

Rain, locally heavy, is expected tonight and tomorrow leading to difficult driving conditions and surface water flooding which could result in disruption to transport and isolated flooding of homes and businesses.

Warnings issued:

• Yellow RAIN Warning (Medium Likelihood of Low Impacts) valid 0300 to 1400 on Wednesday 21st October 2020.

Today / Tomorrow:

Today will see a good deal of fine weather with sunny spells at times but a few showers, isolated heavy, are possible in places. After a fine, dry evening cloud and areas of locally heavy rain will spread north overnight, becoming slow moving by tomorrow morning before gradually easing and clearing away to the north through the afternoon. We could see rainfall totals of 10-20 mm quite widely with a few locations possibly seeing as much as 30-50 mm. Much of the rain could fall in a relatively short space of time (3-6 hours) leading to surface water flooding in places. A few showers may follow into southern areas once the rain has cleared but most places will become dry by the evening.

The Met Office have issued a Yellow RAIN Warning (Medium Likelihood of Low Impacts) to cover the potential impacts from the heavy rain tonight and tomorrow. Impacts could include difficult driving conditions, disruption to transport and isolated flooding of homes and businesses due to surface water and river flooding. The Flood Guidance Statement is also Yellow to highlight the risk of seeing impacts from surface water and river flooding.

Message from the Environment Agency (Thames area):

Localised minor surface water flooding is possible as a result of the heavy rain forecast tomorrow, especially in urban areas. No fluvial impacts are expected and no Flood Alerts are expected to be issued in the South of the Thames area. It is possible that flood alerts may be issued in the North of Thames area on Wednesday as rainfall occurs, we are not permitted to issue pre-emptive flood alerts at present due to Covid-19 restrictions. Across the Thames Area our teams have carried out flood runs to clear trash screens and structures from any debris to ensure they remain operational.

Thursday / Friday:

Generally fine with sunny spells at first on Thursday but showers are expected to develop during the day, possibly heavy with isolated thunderstorms during the afternoon, clearing during the evening. As with any showery situation many places will remain dry. After a fine start to Friday, a band of cloud and rain is expected to move quickly east during the afternoon, clearing during the evening.

Further Ahead:

After another fine start on Saturday a further band of rain is expected to move east during the day before becoming slow moving. There is some uncertainty at the moment where this will stop, and how quickly it will then clear through on Sunday, so it will need to be monitored. The unsettled conditions look like being maintained into next week with further rain or showers at times.

Please keep up to date with the latest Met Office forecast details, warnings and rainfall radar either on Hazard Manager, the Met Office App or Met Office website.