Pre-monsoon showers appear to have given Telangana a miss this year. Barring a few isolated pockets in rural Telangana, there have been no summer showers recorded in the state so far.
The seasonal rainfall received by Telangana between March 1 and April 20, according to the India Meteorological Department, is a massive 87 per cent below normal this year. Ten of the 33 districts have received no rainfall at all this summer.
While the IMD’s meteorological center in Hyderabad on Wednesday predicted light to moderate showers for the next five days, it doesn’t expect anything beyond negligible rainfall in the remote corners of the state. However, there is a reason.
Contrary to popular perception of rising maximum temperatures year after year, the MeT department has observed a normal summer so far with no considerable spike in the mercury level. The IMD has recorded only two heatwave days in the season so far. April, unlike in the past when it regularly recorded six to seven heatwave days, has not seen a single day of heatwave this year.
“The extreme values this time are on the lower side compared to the last 10 years. The departures in maximum temperatures thus far have been in the range of -1.5 degrees Celsius to 1.5 degrees Celsius. The temperatures have started to rise past 40 degrees Celsius only in the last few days, ”pointed out Dr K Naga Ratna, Scientist E and director-in-charge at Hyderabad.
Compared to 2019, when Adilabad in north Telangana recorded a maximum of 45.3 degrees Celsius by the end of April, the maximum maximum temperature recorded in the state this year is 43.5 degrees Celsius recorded in Adilabad on Wednesday.
After it rained across parts of Kerala, Tamil Nadu, and Karnataka in the second week of April, the MeT department in Hyderabad also issued a forecast of light to moderate thundershowers over isolated parts of Telangana between April 15 and 21. But no locations recorded significant showers.
“This is because the maximum temperatures are yet to peak in the state and the air has been less humid to form any instability. The trough passing over Telangana is too weak and there is no upper air cyclonic circulation too. In such a case, we do not see any moderate showers (of up to 6 cm) that were regular in Telangana till 2020. Only light showers can be expected in isolated locations for the next ten days, ”she added.
Referring to IMD’s data for the last 30 years, she said Telangana is expected to receive an average monthly rainfall of three to six days during March, April, and May. A change in the weather pattern, according to her, can be attributed to the changes in the location of formation of the trough and upper air cyclonic circulation or the interannual variability.
Dr YV Rama Rao, former Deputy Director-General of IMD, felt that the summer of 2021, too, was normal though summer temperatures have been rising in the region with every passing year. “The thunderstorm activity has been less this time due to wind discontinuity. We can expect one or two heatwave spells in May. Otherwise, it is going to be a normal summer like last year, ”he said.
Meanwhile, the Telangana State Planning Development Society (TSDPS) with its 1,044 automated weather stations reported heatwave conditions from different isolated locations on Wednesday. A heatwave is recorded when a departure of 4.5 degrees Celsius to 6.4 degrees Celsius is reported and the actual maximum temperature goes past 45 degrees Celsius. According to IMD, if both criteria are met at least in two stations in a Meteorological sub-division for at least two consecutive days, a heatwave can be declared on the second day.
According to the latest edition of ‘Weather and Climatology of Telangana’ by TSDPS, the state receives 56 mm of rainfall in summer, accounting for 6.2 per cent of the annual rainfall of 898.8 mm. Telangana recorded its best summer showers in 1990 when it received 198 mm of rainfall over three months. The worst has been the summer of 2007 when the state recorded only 9.4 mm of rainfall. Each district receives an average of 5 to 7 days of summer rainfall every year.