Strong winds in Poland from the 13th to 18th centuries

For the first time, a comprehensive database of strong winds related to the period prior to 1800 has been created for Poland by team of climatologists and historians based on all documentary evidence available for us. The work was done within a NCN project entitled The occurrence of extreme weather, climate and water events in Poland from the 11th to 18th centuries in the light of multiproxy data. The following documentary sources were used: handwritten and unpublished, published, and so-called secondary literature. The database contains detailed information about the occurrence of strong winds (the location/region, time, duration and indexation for intensity, extent and character of damage), as well as the exact textual content of the original weather note, the name of the source, and an evaluation of the sources quality. Indexation of intensity, initially done by the author of a particular contribution (record), was then evaluated by the whole team preparing the database. Four categories of strong winds were delimited: 1 fresh and strong breeze (Beaufort scale 57), 2 gale (89), 3 storm (1012), and 4 squall (i.e., gusty wind during a thunderstorm). Extent and character of damage was estimated based on the proposition given by Brzdil et al. (2004), slightly modified by us to include the Baltic Sea and its influence on coastal parts. In the database, ~1,200 thus-defined strong winds were identified. The first weather note reporting an occurrence of strong wind (gale) was found for the year 1283. In the paper, the preliminary results describing frequency of occurrence of strong winds in the area of Poland and in its different regions will be presented. In addition, results of the extent and character of damages will be shown. Some case studies of particularly strong winds (including identified tornadoes) will be analysed in detail. The frequency of occurrence of strong winds in the historical period (12011800) and some of its sub-periods will be compared with contemporary results taken from 12 meteorological stations (winoujcie, Chojnice, Olsztyn, Suwaki, Pozna, Kalisz, Warszawa, Siedlce, Krakw, Tarnw, Wrocaw and Opole) from the period 19912020.The work was supported by the National Science Centre, Poland, project No. 2020/37/B/ST10/00710.Reference:Brzdil R, Dobrovoln P., tekl J., Kotyza O., Valek H, Je J., 2004, History of weather and climate in the Czech Lands VI: Strong winds, Masaryk University, Brno.