What This Map Covers
Map viewport is centred on London, England, and takes in the surrounding region. It shows lightning flashes detected from space by the EUMETSAT Meteosat Third Generation Lightning Imager, a few minutes after each flash. Greater London and the Thames Valley see frequent summer thunderstorm activity, with warm plumes crossing the Channel from France and Spain setting off lightning quickly.
This is satellite optical lightning detection: it records total lightning as flashes, does not separate cloud-to-ground strikes from in-cloud flashes, and places each flash approximately rather than to the metre. It is not rainfall radar, not a forecast and not a complete storm archive. Thick cloud and processing conditions can cause flashes to be missed. This is not a Met Office product and carries no official warning status.
Safety limit: absence of a marker never proves outdoor safety. Satellite detections can be delayed or missed, and storms move between refreshes.