ИСТИНА

Specific features and parameters of squalls both in Moscow and in some Indian cities are discussed. A total statistics during recent decades represent that this dangerous weather phenomenon is observed in European part of Russia as a rule in summer or, sometimes, in spring (from April to August), whereas in India – usually at pre-monsoon time from March to June. The highest wind gust VMAX during squalls only in rare cases may reach 30 m/s or a bit larger: in Moscow suburbs the highest value 30 m/s in time of squall was detected in May, 2017; for Indian conditions it was equal to 33.3 m/s in Western India in Gujarat state in March, 2015. However, in more than 90% of all squall cases in recent years in India the highest wind speed was detected as less than 25 m/s (at least, at the closest weather station). In diurnal course squalls are observed usually both in Russia, and in India in the afternoon or at late evening time and almost never in the early morning. As a rule squalls are connected with thunderstorms but sometimes they may exist as separate phenomenon in absence of thunderstorm. One such example was a terrible squall in Moscow city which took place in May 29th, 2017. The meteorological conditions of this event, including stationary, radar and sodar data are discussed in details. Probably, the main reason of this squall was a quick passage of sharp cold front and its very narrow zone.