Synoptic situation over the central area of the European part of Russia (ETR) on June 12, 2014 was determined by the rear part of the sedentary cyclone centered near Penza.
In Moscow and the surrounding area in the morning on June 12 was observed weather with almost no clouds and temperatures near the ground 12 ° C, a relative humidity of 75%, low (2-4 m / s) north-east wind.
From 11.00 am to the north-east of Moscow in the region of Aleksandrov-Kirzhach started developping of cells cumulonimbus clouds moving towards Moscow at the speed of 35-40 km / h. The upper boundary of the cloud reached 4000-5000 m.
At this time in the air were two aircraft (aerial works on 12.06.2014 were started at 04.05am when the plane laboratory Yak-42 (b/n 42440) «RosHydromet» was raised in the air) that started the impact on clouds north and north-east of Moscow.
Due to the complicity meteorological situation before 3.30pm 8 more aircrafts were raised in the air. During this period at distances up to 150 km to the north-east of Moscow were formed ridge active thunderstorm cells with rainfall intensity up to 20-40 mm / hour and heights of up to 8.9 km (Fig. 1).
Despite intensive exposure in Moscow from 1.50 pm to 2.20 pm and 4.30pm to 5.30 pm in some places there were short-term heavy rainfalls with a total layer of 1-3 mm.
Exposure continued until 11pm when the Customer instructed to stop the works.
On 12.06.2014 in total 15th flights were made.
After 5.30 there was no rain in Moscow.