Difficult to predict freezing precipitation from 23 to 29 January 2023

Between January 23rd and 29th there were low stratus clouds above most of the Czech Republic. Light freezing drizzle was falling, even though the entire cloud layer was within a temperature range below 0 °C. The drizzle was hard to detect, all the forecasters often relied on observation from professional weather stations and eyewitness reports from the public on social media. However, locally there were major complications, especially in transport. This freezing precipitation was caused by the so called SWRP (Supercooled Warm-Rain Processes). A bit unusual precipitation development on such a large scale and its complicated detection were a true challenge for forecasters on duty, and showed the importance of cooperation between professionals, amateurs and public. Also observations from professional weather stations showed their irreplaceability.