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Thunderstorms, rains hit Delhi; IMD prediction falls flat
Delhi has now recorded 90.8mm in monthly rainfall, nearly three times the long-period average of May, which is 30.7mm
New Delhi
An intense but short spell of thunderstorm, accompanied by rain and gusty winds of up to 60 kilometres per hour (kmph) speed, hit the Capital late Tuesday afternoon, catching residents off guard and debunking the India Meteorological Department’s (IMD’s) prediction of a hot day with winds of speed up to 20kmph.
The vigorous rain spell caused waterlogging in isolated parts of the city, in continuation of a fairly wet start to May, which is generally the hottest month of the year. With this spell, Delhi has now recorded 90.8mm in monthly rainfall, nearly three times the long-period average of May, which is 30.7mm. Last May, Delhi recorded only 0.4mm of rainfall.
For Tuesday, IMD had not forecast rain, but a fairly hot day, which held true for the first half, as the maximum temperature hit 40.2 degrees Celsius (°C), which was a degree below normal. However, thunderclouds started developing around 3pm, and short-intense bursts of rainfall and strong winds were recorded in most parts of Delhi between 3.30pm and 5pm.
An IMD official said this was “convective rain”, a phenomenon when temperatures are high and the introduction of moisture leads to localised spells of short but intense rainfall.
Despite the late evening cool, it was the first time the maximum temperature crossed 40°C since April 28, when a maximum temperature of 40.4°C was recorded. “We had intense convective cells forming over Delhi, Haryana and Uttar Pradesh. This was due to high temperatures already existing in the region. When that is the case, even slight introduction of moisture can lead to rapid formation of thunder clouds,” the IMD official said.
Terming it a “common occurrence” in pre-monsoon, the official said forecasting remains “immensely tricky” due to such phenomena.
To be sure, this was not the first time IMD was caught off-guard this month. For May 2, IMD forecasted light rain or drizzle, but 77mm of rainfall—the second-highest single-day rain spell for May—was recorded.
On Tuesday, Delhi’s base weather station at Safdarjung clocked 0.2mm of rainfall between 2.30pm and 5.30pm, according to the IMD. In the same period, the Palam station recorded 5.6mm, Ridge 2mm, Pitampura 4mm, Rajghat 0.1mm and Ayanagar and Lodhi Road each recorded “trace” rainfall.
For Wednesday, the IMD does not have a colour-coded alert in place and it forecast partially cloudy skies, no rainfall and surface winds of 15-25kmph, occasionally gusting to 35kmph. The maximum may rise further and is likely to hover between 39°C and 41°C, it said.
Delhi’s minimum temperature, meanwhile, was 27.7°C on Tuesday, which was two degrees above normal. It is likely to hover in the 27-29°C range on Wednesday, according to the prediction.
The rainfall also improved the city’s air quality. The 24-hour average air quality index (AQI) was 141 (“moderate”) on Tuesday, marking an improvement from an AQI of 162 recorded a day earlier. The Centre’s Air Quality Early Warning System for Delhi forecasted the AQI to remain “moderate” until Friday.
