Weather report: Western disturbances bring a cold start to May, cyclonic circulation may develop in Bay of Bengal soon

Weather takes a U-turn as heatwave exits, May, the hottest month in the entire country, starts on a record breaking cold note for many regions in India. On 1 May, Ridge station in Delhi recorded a minimum temperature of 16.3°C which is lowest ever in the month of May. Also, Kota in Rajasthan sets a new monthly record by noting down 19.4°C minimum temperature. May started on a historical cold note in north India, some stations in Himalayas recorded lowest ever maximum temperatures, breaking their previous all time records. • Dharamshala: 8.4°C, broke the previous all time record of 8.7°C from 6 May, 2009. • Mukteshwar: 10.8°C, matched the previous all time record of 10.8°C from 3 May, 1969. • Dehradun: 19.9°C, broke the previous all time record of 23.0°C from 6 May, 2000. The fair drop in temperature is caused by good rains over the hills, rainfall data ending on 2 May: Katra: 52.8 mm Batote: 44.7 mm Nainital: 31.0 mm Manali: 24.0 mm Pithoragarh: 19.4 mm Jammu: 17.4 mm Mussoorie: 16.7 mm Dehradun: 13.7mm Pantnagar: 13.6 mm Solan: 11.2 mm Shimla: 8.0 mm Mandi: 7.4 mm Bhuntar: 4.3 mm Maximum temperature and it’s departure from normal in some stations of Uttar Pradesh and Delhi on 1 May, 2023 Meerut: 22.2°C (-16°C) Bareilly: 29.1°C (-10°C) Aligarh:25.6°C (-13°C) Bijnor: 20.5°C (-16°C) Jhansi: 33.4°C (-9°C) Lucknow:30.0°C (-9°C) Shahjahanpur:30.5°C (-7°C) Delhi (Safdarjung):26.1°C (-13°C) Delhi (Palam): 25.5°C (-15°C) [caption id=“attachment_12546052” align=“alignnone” width=“449”] Highly below normal temperature across the country on 2 - 3 May, 2023[/caption] Rain, Hails and thunderstorms lashed various parts Delhi NCR on Wednesday and Safdarjung observatory recorded 21 mm till 8:30 PM surpassed the monthly average of 19.7 mm as 37 mm has occurred in the first three days of May itself with this the annual total so far stands at 130.3 mm. What resulted in abnormal temperature drop in North India? The western disturbance is a common phenomenon in the summers as they approach north India quite frequently and bring on strong dust storm and rains May result in drop in temperatures, this time the western disturbance was a very strong westerly system as the jet streams at 200 hpa was dipping as low as south India and combined with the existing deep convergence in peninsula, due to the combination of the weather systems the moist winds from Arabian Sea and Bay of Bengal have never stopped the excessive moisture in the atmosphere kept the hold of clouds stronger over the entire company of a couple of days, rains and dense overcast conditions lead to almost negligible sun radiation up to the surface, the earth surface never warmed up and went into an exceptional cool down phase which is not the tendency of weather conditions in the first week of May. [caption id=“attachment_12546062” align=“alignnone” width=“454”] Massive moisture drag from the Bay of Bengal and Arabian sea as observed on lower level winds[/caption] The pre-monsoon seasonal rains so far in the country have been fairly above normal except in the parts of north-east India. In the period of 1 March till 3 May the country as whole received 95.4 mm rainfall against the normal of 74.3 mm, the departure from normal stands at +28 percent. Subdivision-wise seasonal rainfall in the period of 1 March till 3 May, 2023 • Southern Peninsula: Actual 102.0 mm against the average of 54.2 mm, +83 percent departure from normal. • East and North East India: Actual 141.1 mm against the average of 199.9 mm, -29 percent departure from normal. • North West India: Actual 98.3 mm against the average of 83.4 mm, +18 percent departure from normal. • Central India: Actual 67.0mm against the average of 18.2mm, +268% departure from normal. Current synoptic features influencing weather in India as on 3 May, 2023: • The western disturbance as a trough with its axis at 5.8 km above mean sea level now runs roughly along Long. 70°E to the north of Lat. 25°N. • The western disturbance as a cyclonic circulation over Haryana & neighbourhood extending up to 4.5 km above mean sea level persists. • The trough/wind discontinuity from southwest Madhya Pradesh to south Tamil Nadu across Marathwada and interior Karnataka at 0.9 km above mean sea level persists. • The cyclonic circulation over south Chhattisgarh & neighbourhood up to 0.9 km above mean sea level persist. • The cyclonic circulation over South Interior Karnataka & adjoining Tamil Nadu between 1.5 km and 3.1 km above mean sea level persists. • The trough from the above cyclonic circulation over South Interior Karnataka and adjoining Tamil Nadu to Southwest Bay of Bengal off north Sri Lanka coast between 1.5 km and 3.1 km above mean sea level persists. • A fresh western disturbance likely to affect northwest India from the night of 05 May, 2023. • A cyclonic circulation is likely to develop over southeast Bay of Bengal around 06 May, 2023. Under its influence, a Low Pressure Area is likely to form over the same region during subsequent 48 hours. What’s ahead with the erratic weather? The seasonal heat waves will remain absent till 10 May as below normal temperatures will persist across the country. The wet phase of weather will last at least up to the weekend at the Himalayas, Punjab, Haryana, Delhi NCR, Uttar Pradesh, Bihar, Jharkhand, West Bengal and reduce significantly thereafter. The rains in peninsular states of Telangana, Andhra Pradesh, Tamil Nadu, Kerala, Karnataka will continue to hold strong till early next week and may take a pause for a few days in between. A cyclonic circulation is likely to develop over the south-east Bay of Bengal by 6 May, 2023, and it might intensify into a cyclonic storm by next midweek. Generally, pre-monsoon cyclones moving parallel to the east coast of India hit towards West Bengal, Bangladesh, or Myanmar. As jet streams are quite strong these days, they may keep the storm slightly off the coast of India. Still, there is a lot of uncertainty as the key atmospheric features that help identify the track of the cyclone are yet to develop. Meteorologists will have a clear picture by the weekend. The author, better known as the Rohtak Weatherman, interprets and explains complex weather patterns. His impact-based forecasts @navdeepdahiya55 are very popular in north India. Read all the  Latest News ,  Trending News ,  Cricket News ,  Bollywood News , India News  and  Entertainment News  here. Follow us on  Facebook,  Twitter and  Instagram.