08.07.14 Just to let you know there are some heavy showers developing across London today and that a Yellow warning has been issued.
Showers have already started to develop to the south and east of London which are drifting slowly eastwards. These will become more widespread as we go through the afternoon into the evening, turning heavy with isolated thunderstorms. There showers could generate 15-20 mm of rain in an hour and perhaps up to 30 mm in two hours. As with any showery situation some places could see very little rain or none at all. Where the showers do occur, they could lead to difficult driving conditions and some surface water flooding as well as impacts caused by lightning. Although most impacts are likely to be minor a few isolated locations could see more significant impacts.
The Met Office have issued a Yellow RAIN Warning (Very Low Likelihood of Medium Impacts) which is valid until 19:00 this evening. Details can be viewed on Hazard Manager or on the Met Office website at http://www.metoffice.gov.uk/public/weather/warnings/#?tab=warnings®ionName=se. I would encourage you to keep an eye on the radar rainfall graphics through this afternoon to monitor the movement and development of the showers.
The showers will gradually die out late this evening to give a dry night. Tomorrow should remain mostly dry but rain will spread westwards overnight Wednesday / Thursday, slowly clearing during Thursday. Towards the end of the week and into the weekend there is the likelihood of further heavy showers, some turning thundery.