Chandigarh, May 29 -- Amid predictions of rain and thunderstorms owing to an active western disturbance in the region, the city's maximum temperature dropped to 40degC on Thursday after hovering in the 41-43 degree range for nearly a fortnight. Though no rain was recorded during the day, India Meteorological Department (IMD) has predicted thunderstorms, lightning and squall, with speed upto 70-80 kmph, on Friday. A red alert has also been issued for the day. Red is the most severe of the four-colour alert system issued by the IMD, which asks people to remain cautious during thunderstorm activity, avoid sheltering under trees and unsecured structures, and stay updated with official weather advisories. The system will continue till Sunday, when rain is expected at isolated places, while gusty winds of 50-60 kmph are expected at isolated locations on Saturday. The temperature is likely to drop by 6degC to 8degC over thenext four days, Met officials said....