Analysis of the severe weather situation May 20th 2020

The week that just ended was characterized by the advance of a warm air mass over most of the Balkan Peninsula and the central-southeastern part of the continent, including over the geographical territory of Romania.

Warm and humid weather in the early part of the interval was associated with the action of a low pressure core in the central Mediterranean basin.

The hot weather was not without meteorological phenomena specific to atmospheric instability, such as electrical discharges, rains in the form of downpours that also had a torrential character, wind intensifications and hail.

Of interest were the days 19 and 20 May 2020, when the Mediterranean depression core transported warm and moist air to the northern Balkans and the central-south-eastern part of Europe.

Figure 1. Synoptic context Europe 20.V.2020, time 00 UTC

Simultaneously with the Mediterranean depression, a core of cold air was also active in the altitude, it favored an acceleration of the convective processes for the mentioned interval.

The junction of warm and moist air with the cold front favored the development of large convective cloud systems.

The atmospheric front in question came on a west-southwest component (fig.1), hence the dominant direction of movement of the convective cloud formations from the southwest to the northeast.

The evolution of the convective parameters, favorable to the convective initiations that affected the south-western part of Romania, were also illustrated very well on the radiosonde data taken from the territory of Serbia, for the town of Nis (fig. 2A), but also for Sofia, western Bulgaria (fig. .2B).

It should be noted that the presented products are valid for 12 UTC, conditions in which the convective parameters, most of the time, reach the maximum at 15 UTC.