572 mm of rainfall in just 48 hours: a battering that Wayanad did not anticipate

The outpour had slowed on July 30, but not enough to avert the tragedy that struck Wayanad in Kerala in the wee hours of the day. A glance through the amount of rain that battered the State reveals that a station called Thettamala in Wayanad received a whopping amount of 409 mm of rain during the 24 hours ending at 8.30 a.m. on Tuesday. Even Vadakkanecherry in central Kerala received 340 mm of rainfall during the same period, perhaps one of the heaviest rains the State had seen during the opening two months of the southwest monsoon season

Chief Minister Pinarayi Vijayan in his media address said that, as per the forecast issued by the India Meteorological Department (IMD) on Monday, the area was supposed to witness rainfall in the range of 64 mm to 204 mm (orange alert) in the 24-hour format. However, the area where the mishap occurred witnessed 200 mm of rain in the first 24 hours and 372 mm of rain in the next 24 hours, a total of 572 mm of rain in just 48 hours.

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“Accumulated impact”

Speaking to The Hindu, Neetha K. Gopal, IMD director, Thiruvananthapuram, said: “It’s true that we had not anticipated an extreme rainfall event, but had been expecting some intense spells in north Kerala. As per our observation, it was the accumulated impact of the rain that led to chaotic scenes in Wayanad. The soil was already in saturated mode during the heavy rains the previous day, and the excess precipitation on that fateful night led to the catastrophe. The IMD is exploring ways to introduce a nighttime analysis of the weather parameters during the peak season, considering the pattern of rains in Kerala.”

“For instance, during the active monsoon season, high intensity rainfall occurs during the night and early morning due to the effect of various oceanic factors in coastal States. So, analysing the weather parameters, including local factors, during the night will provide some leeway. However, the window for acting during these situations would be limited, especially in our tropical climate where the atmospheric developments are very fast and quick,” added Ms. Gopal.

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Meanwhile, the heavy rain that had been pounding the State, especially north and central Kerala, for the past two days is likely to continue for a couple of more days, triggered by the offshore trough at mean sea level that persists along the south Gujarat to Kerala coast. The State is also likely to receive heavy rainfall for the next two to three days, powered by strong westerly and north-westerly winds in the lower levels over Kerala. An orange alert has been issued for five districts from Malappuram to Kasaragod on Wednesday, warning of very heavy rainfall, and a yellow alert for four districts — Ernakulam, Idukki, Thrissur and Palakkad — forecasting isolated heavy rains.