The weather warning is active from 8 p.m. today until 1 a.m. Saturday for the entire Karlovy Vary and Pilsen regions, most of the Ústí nad Labem area, and the western part of Central and South Bohemia. From 1 a.m. Saturday, the warning will apply to the whole country, which in most areas will end at 7 p.m on the same day.