Extreme summer precipitation in Siberia in 2015–2021

There is an increase in anomalies of various geophysical parameters, an increase in the frequency, intensity and spatial scale of extreme weather events. This is of concern to scientists, businessmen and ordinary people, because it can lead to an increase in economic and social damage in various regions. Analysis of changes in the characteristics and conditions for the formation of extreme precipitation is important. They are formed unevenly in time and territory. Their analysis can help refine the methods for predicting such events, as well as the consequences of their impact on the regional economy and population.

The climate is continental in Western Siberia. Most of the precipitation falls on the warm half of the year. Most of this precipitation is torrential rain. We have studied extreme precipitation and the conditions of its formation according to the data of 200 meteorological stations in Siberia. We used data from storm warnings in the WAREP code provided by the Federal State Budgetary Institution "West Siberian UGMS" and daily data from the open database [meteo.ru]. We also used satellite remote sensing data. Cases with the following dangerous and unfavorable phenomena were considered: "heavy rain" and HH "very heavy rain". Their criteria are given in the relevant ruling document.

During the considered period of years, the maximum number of “heavy rain” events was observed at Raduzhny and Staritsa stations. These stations are located in the area of the rarefied water system of the Great Vasyugan swamp complex. Such conditions are one of the factors in the formation of the following dangerous and unfavorable phenomena in a given territory. They enhance convection. It was found that in the study area, the phenomena of "heavy rain" and "very heavy rain" were most often observed under the conditions of the formation of mesoscale convective complexes. In some cases, the considered events with extreme precipitation were observed when the mesovortex was cloudy or during the passage of a cold front.

In order to detect the presence or absence of the following dangerous and unfavorable phenomena from satellite images, V.V. Chursin developed an original algorithm. Data from the NOAA, MetOp and SUOMI-NPP polar orbiting spacecraft were used to analyze and verify this algorithm. The model made it possible to identify in advance the zones of potential extreme precipitation over the study area. High estimates of the reliability of detection of probable zones of the following dangerous and unfavorable phenomena were obtained.