The aerosynoptic situation in the Moscow region on May 9, 2023 was determined by the central part of the Arctic anticyclone. At night and in the morning, partly cloudy weather was forecast, without precipitation.

During the day, when warming up, the development of cumulus clouds is possible, which could lead in places to light precipitation (0,1 – 0,2 mm) with a probability of 30%.

In the free atmosphere at all altitudes (up to 10 km), a north-easterly wind of 5-10 m/s was observed during May 9. In the morning the air temperature was 2…4 oC, in the afternoon the maximum was +13…15 oC.

Cumulus clouds, which appeared in the middle of the day, did not develop above 3-3,5 km and did not give precipitation.

In accordance with the weather forecast issued by «Hydrometeorological Bureau of the Moscow and Moscow region», from 04:00 to 6:00 MSK, three AN-12 aircraft (№ 09, 25 and 17) were lifted into the air from the Chkalovsky airfield to carry out sounding and monitoring of the weather situation in the northwest, north and northeast at the distance of 100-250 km from Moscow.

Taking into account the forecast of temperature increase from 8 a.m., three AN-26 aircraft (№ 90374, 57 and 51) were additionally involved, which together with AN-12 aircrafts, continued to monitor weather conditions in the same areas of the Moscow air zone in order to prevent possible precipitation due to the development of local convection at the distance up to 250 km from the city.

In the period from 12:15 to 13:00 MSK, three more AN-26 aircraft (№ 55, 10 and 03) were lifted into the air, which operated in an area limited by azimuths of 330 – 5 degrees and ranges up to 100 km from Moscow.

At 6:30-6:40 and 08:17 – 08:24 MSK, packages with coarse powder were dumped near Tver and Kaluga area. As a result of seeding of altocumulus clouds with a height of the upper boundary of the radio echo of 3-3,5 km, the disappearance of the zones was observed after 1-2 hours.

The work on improving weather conditions in Moscow was completed by agreement with the Customer at 15:40 MSK. A total of 9 airplane flights were carried out on May 9, 2023.