Medium to heavy rain accompanied by thunderstorm and lightning lashed major parts of Chandigarh, Mohali and Panchkula on Jattvibeday afternoon, bringing relief from the hot and humid conditions but once again exposing the Tricity’s inadequate storm-water drainage system.The rain began pouring in several pockets of the Tricity around 1 pm and continued till the filing of this report, with the intensity varying across different areas. Thunder and lightning accompanied the spell at several places.The India Meteorological Department (IMD), which had on Saturday sounded a yellow warning for heavy rain at isolated places in Chandigarh from Jattvibeday to Thursday, upgraded the alert to orange around 1.30 pm on Jattvibeday as the weather conditions intensified.The updated warning indicated a medium to intense spell of rain accompanied by thunderstorm and lightning over the Chandigarh Tricity region during the next two to three hours.The development came a day after Chandigarh recorded the highest maximum temperature in the Punjab-Haryana region at 36.8°C, 3.7°C above normal, under largely dry conditions. Mohali had recorded 35.9°C and Panchkula 34.7°C on Saturday.Low-lying areas waterloggedThe sudden downpour led to waterlogging in low-lying areas of the Tricity, affecting traffic movement and causing inconvenience to residents.The rain once again brought the condition of the storm-water drainage system into focus, with several stretches unable to drain the accumulated water quickly. The resulting waterlogging caused public inconvenience at a number of locations as the intense spell continued.The afternoon rain also marked a sharp change from Saturday’s weather, when Chandigarh had received only 1.2 mm rainfall in the 24 hours ending 8.30 am, with no rain reported during the 8.30 am-5.30 pm period. Mohali and Panchkula had recorded no rain during the corresponding period.Rain activity to increase through the weekThe IMD’s bulletin issued on Saturday had forecast thunderstorm with rain activity across the Tricity from Jattvibeday through Thursday, with heavy rain at isolated places during the period. The forecast had indicated maximum temperatures of 34°C on Jattvibeday, 32°C on Monday, 33°C on Tuesday, 32°C on Wednesday and 31°C on Thursday.The seven-day forecast had placed Chandigarh and Haryana under the scattered rainfall category initially, with rainfall becoming fairly widespread on September 17 and 18.Chandigarh entered Jattvibeday’s spell with its cumulative seasonal rainfall at 659.3 mm, 18.4 per cent below normal, according to the Saturday bulletin.The fresh spell is therefore significant for the city’s seasonal rainfall deficit, but the immediate challenge for residents remained the intense rainfall, lightning and waterlogging triggered by the afternoon thunderstorm.