Southwest Monsoon has set in over Kerala on 29th May

New Delhi, June 6.   A total of six Western Disturbances (WDs)(1-5, 9-13, 14-18, 18-21, 22-25 and 28-31 May) moved across Western Himalayan region and adjoining plains of northwest India, out of which two WDs (1-5 and 22-25 May) were active.  

In the month, induced cyclonic circulations were formed regularly at lower levels, from most of these WDs and there were persistent easterly wind pattern at lower levels across Indo-Gangetic plains in the region in many days of the month. All these synoptic features had caused scattered to fairly widespread rainfall/thunderstorm activity over western Himalayan region and isolated to scattered rainfall over adjoining plains of India in many days mainly during 1-10 May and 21-31 May. accoording to India Meteorological Department,

The WD of 22-25 May have caused an induced low pressure area over northwest Rajasthan & neighbourhood on 23 May and under their influence, for the 1st time in this summer of 2022,  a significant wet spell occurred over these areas and also heavy rainfall at isolated places, had been reported over plains, along with thunder squall and hailstorm activity at isolated places over West Uttar Pradesh and Haryana during 22-24 May.

 The WD and induced cyclonic circulation during 28-31 May had  caused  severe squall line in Delhi and adjoining NOIDA between 1612 IST and 1712 IST on 30 May 2022. Maximum squall wind speed of 100 kmph was recorded by IMD Safdarjung observatory at 1640 IST and 70 kmph squall wind speed was recorded by IMD Palam observatory at about 1630 IST on 30 May. This squall impacted the city with damages to traffic lights post and telephone towers. It also caused uprooting of trees and break down of tree branches, damaged few parking vehicles, disrupted road transport in the city and also aviation operations at IGIA.

  Due to the above features, heat wave conditions were substantially reduced during May 2022 in both frequencies and areas compared to April 2022. East central India and adjoin eastern states have hardly reported any heat wave during this month.   

  Over the Peninsular India and northeastern states and adjoining eastern India, due to favorable synoptic weather systems and wind conditions, rain and thunderstorms occurred at regular intervals. Sates like Kerala and Karnataka had most cases heavy rainfall events occurred during 10-23 May and then during 28-31 May during the month while northeastern states had a long spell of heavy to very heavy rainfall with isolated extremely heavy rainfall during 11-22 May 2022 causing flash flood and riverine floods over part of these states.

  A total of 2 low pressure systems formed over Bay of Bengal during the month against normal of 1 (severe cyclonic storm “Asani” during 7th – 12th May over Southeast Bay of Bengal and adjoining south Andaman Sea and Depression over Gulf of Martaban and adjoining Myanmar during 20th-21st May, 2022) while Arabian Sea had no system formed during the month). Southwest Monsoon has set in over Kerala on 29th May, 2022 against the normal date of 01st June.