Chennai and suburbs have received moderate showers yesterday afternoon and evening. Base observatory at Regional Meteorological Center Nungambakkam recorded 32mm of rainfall in 24hr. Airport Meenambakkam measured only 6mm rainfall during the same period. More showers are likely over the next 3 days.
Unlike most locations over central and northern parts of the country, month of September is more rainiest than July and August for Chennai. In anticipation of Northeast Monsoon, the rainfall increases further in October and peaks in November. Month of September has a modest normal of 146.2mm rainfall and the city has received 92mm, so far. Light to moderate showers are expected in the remaining days, possibly amounting to 20-30mm rainfall. Therefore, it may fall short of the monthly target, albeit by small margin.
Cyclonic circulation is marked over West-Central Bay of Bengal, up to mid-tropospheric levels. Trough line is extending along the east coast from Odisha to Tamil Nadu, across coastal Andhra Pradesh. This feature will persist for the next 3 days. Factually, another system may evolve over Bay of Bengal over the same area anytime around 01stOct and prevail for the subsequent 3-4days. Therefore, even after cessation of the current spell, light rains may continue later as well.
Most of the weather activity is expected during evening and night hours. The spread, intensity and duration could be more on 28th& 29th Sep. Maximum and minimum temperatures will range around mid 30’s and mid 20’s respectively. Warm and sultry conditions are likely during the day. Southwest Monsoon seasonal rains get over on 30th September but the southern parts, including Chennai remain under the influence of retreating monsoon, at least till mid October. City awaits the onset of Northeast Monsoon, the rainiest period, anytime from 20th October onward.