So are there real hurricanes in Moscow or not? We analyze the case of March 13, 2020 in hot pursuit

Following the events of March 13, 2020. Unknown results of the “hurricane” in Moscow: comment by a professional meteorologist.

Last Friday, March 13 (Friday the 13th!), In the capital again due to the approaching cyclone, gusts of a gust of wind were noted, trees fell, and, to my deep regret, there were again no casualties. The Ministry of Emergency Situations sent SMS (with varying degrees of lead time as usual), the official forecast of the Hydrometeorological Center of Russia spoke about gusts of wind with a speed of up to 25 m / s. As a result, gusts of up to 22 m / s were observed in Sheremetyevo and in Vnukovo, at the city weather stations - VDNH and in Baltschug the wind increased to 14 m / s. This is quite normal - at a 10-meter height (attention is not at the level of your face, because it is on it that meteorologists from all over the world usually measure wind speed, and they also predict) in the city due to the building the wind speed is generally lower than in the suburbs .

News feeds again became full of reports about a hurricane in Moscow, they were deservedly harassed by experts, rightly noting that a hurricane is a steady wind with a speed of 32 m / s and higher (Meteorological Dictionary edited by Khromov and Mamontova), which means that there are real hurricanes in the capital the entire history of meteorological observations (since 1879) was not observed. Nevertheless, from classical urban meteorology, it is known that with a certain configuration of urban development, the wind can be amplified at individual points due to the effect of the wind tunnel.

As true urban microclimatologists, we at the Smart Technologies Center for Sustainable Development of Urban Ecosystems under the Global Changes at RUDN University (Moscow) decided, using the latest developments in the field of eddy-resolving modeling, to find out:and what theoretically can happen, say, on the campus of RUDN University (south-west of Moscow) (Peoples' Friendship University of Russia) if the forecast is fully justified? That is, a gust of southwest wind flies at a speed of 25 meters per second.

For this, we used a non-hydrostatic eddy-resolving version of the ENVI_MET microclimatic model with a resolution of 3x3 meters. Naturally, the experiments were preceded by months of work on “digitizing” the territory, clarifying the position of trees, adjusting the parameters of the heat balance, model turbulence, etc.

→ Here you can navigate the location of the research area on a Google map of the south-west of Moscow.

Having fully loaded our modest server for the whole Friday, in the end we got a very eloquent result. At an altitude of 10.5 meters in some places wind speeds can reach 38 m / s (hurricane rush!), At the level of "human communication" - 29 m / s. Here it is in more detail: two such maps, one for wind speed at a height of one and a half meters, the other at 10.5 meters. The strongest winds are observed before obstacles and after the previous “dispersal”.

Map of the distribution of wind speeds at a height of 1.5 meters

A map of the distribution of wind speeds at a height of 10 meters

It would be nice to ask urban planners and architects - is this taken into account when planning "public spaces", etc.? Because 38 m / s at the level of 4 floors or the crowns of a rotten tree is no longer a joke.

Thus, with every storm warning justified about gusts of wind up to 25 m / s, hurricane gusts at least ten meters high can occur in some parts of urban microdistricts EASY . So, they have repeatedly been to the capital. That is, strictly speaking, there were no hurricanes in the full sense of the word, but hurricane outbursts - please !

Keep this in mind, dear friends, and be careful on such dangerous days.

To be continued.