Cyclone ‘Arnab’ to form? IMD warns of deep depression, shares landfall update; Odisha schools shut | India News

A weather system in Bay of Bengal is advancing, intensifying and likely to cross Andhra Pradesh-Odisha coast soon, the India Meteorological Department said on Tuesday.The IMD said in a post on X at around 11:45 am on Monday that a depression over west central and adjoining northwest Bay of Bengal is likely to intensify into a deep depression soon.“The Depression over Westcentral & adjoining Northwest Bay of Bengal, moved westwards with speed 18 kmph during past 06 hours and lay centred at 0830 hrs IST of today, the 22nd September, 2026, over the same region near latitude 17.9°N and longitude 86.0°E, about 200 km southeast of Gopalpur (Odisha), 200 km east-southeast of Kalingapatnam (Andhra Pradesh), 210 km south of Puri (Odisha), and 290 km east of Visakhapatnam (Andhra Pradesh),” the IMD said on X. “It is very likely to move west-northwestwards & intensify into a deep depression over Westcentral & adjoining Northwest Bay of Bengal during next 12 hours," IMD said, adding that the system is forecast to continuing to move west-northwestwards.The IMD said it is very likely to cross north Andhra Pradesh-South Odisha coasts between Visakhapatnam and Gopalpur as a deep depression during night of September 23 to early hours of September 24 - i.e. Wednesday and Thursday. According to the roster that lists names of cyclonic storms, the next cyclone that forms in the North Indian Ocean will be named Arnab.The name Arnab (which means "ocean" in Bengali) was contributed by Bangladesh to the regional tropical cyclone naming list maintained by the World Meteorological Organization (WMO) and the India Meteorological Department (IMD).Odisha schools shutSchools and anganwadi centres in four districts of Odisha were declared shut amid IMD prediction of a deep depression over the Bay of Bengal that is likely to bring heavy rainfall to the state over the next two days.Some places could receive up to 20cm of rain, while winds of 55-65 kmph are expected from Tuesday evening, according to estimates mentioned in an earlier HT report.IMD scientists warned that the heavy rainfall could lead to rising water levels in rivers and cause flooding in low-lying areas, particularly in places that have already received sustained rain.In Khurda district, all schools were asked to remain shut from Tuesday to Thursday as a precautionary measure while in Ganjam district, the district administration has ordered the closure of all government, government-aided and private schools for the same period.Jagatsinghpur district administration has announced the closure of all schools and Anganwadi centres on Tuesday. In Gajapati, schools and Anganwadi centres will remain shut from Tuesday to Thursday. The order covers both government and private institutions.How are low-pressure systems, depressions classified?According to IMD website, the weather department classifies low-pressure systems based on their intensity, using pressure patterns over land and maximum sustained wind speed over the sea. A system is classified as a low-pressure area when it has one closed isobar, while a depression has two and a deep depression has three. A system with four or more closed isobars is classified as a cyclonic storm.Based on wind speed, a system with maximum sustained three-minute surface winds of 17-27 knots (31-50 kmph) is called a depression, while 28-33 knots (52-61 kmph) is classified as a deep depression. Once maximum sustained winds reach 34 knots (63 kmph) or more, the system is classified as a cyclonic storm. Thus, a low-pressure area does not automatically mean a cyclone; it must intensify and cross the prescribed thresholds to be classified as one.