This study investigates how the duration and four calculated characteristics of precipitation events change in relation to the supposed increase in ground temperature during the 21st century in the warm part of the year. We analysed measured hourly precipitation totals at 97 stations in the Czech Republic during 1998–2014, hourly precipitation totals from a reanalysis for the period 1990–2014, and projected precipitation totals for the period 2026–2100 for two future climate scenarios (SSP5–4.5 and SSP5–8.5, which represents “middle of the road” and very strong impact of CO2 concentrations on climate, respectively).
We defined a precipitation event (PE) as continuous sequence of hourly precipitation values with a threshold of at least 0.2 mm/h and a duration from 1 to 23 h. The ALADIN-CZ numerical weather prediction model was used to calculate reanalysed PE, while the ALADIN-CLIMAT-CZ climate regional model was used to calculate projected PE for 25 years long periods (2026–2050, 2051–2075 and 2076–2100). The two models are very similar and differ in the input data only. Both models belong to the so-called convection permitting models. A unique feature of the models is their high horizontal resolution of 2.3 km.
We studied the four characteristics of PE in dependence on duration and ground temperature: (i) the relative frequency of PE; (ii) relative total precipitation of PE; (iii) relative mean precipitation of PE, and (iv) relative maximum precipitation of PE.
We found that some characteristics of observed PE clearly differ from reanalysed data, while others are very similar. The main difference is that the reanalysed data give longer PE for higher temperature, where the measured data do not indicate any PE. In contrast, the reanalysed and projected PE show consistent results. The main result of the study is that the duration of PE does not exhibit any change with increasing temperature.
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