Thiruvananthapuram witnessed heavy rain on Monday
KOCHI: Even though large parts of Kerala were left looking into the skies for some rains, the India meteorological department (IMD) declared the onset of southwest monsoon over Kerala on June 1 based on the parameters fixed for declaration of an onset.
To declare an onset, IMD looks at certain parameters like rainfall, wind field and outgoing longwave radiation (OLR). If after May 10, 60% of the available 14 stations, viz. Minicoy, Amini, Thiruvananthapuram, Punalur, Kollam, Alappuzha, Kottayam, Kochi, Thrissur, Kozhikode, Thalassery, Kannur, Kudulu and Mangalore report rainfall of 2.5mm or more for two consecutive days, the onset over Kerala will be declared on the second day.
On Monday, IMD said that widespread rainfall occurred over Kerala during the past two days.
More than 70% of the 14 rainfall monitoring stations for monsoon onset over Kerala have reported rainfall during the last 48 hours.
There is an orange alert for Kozhikode with a warning of very heavy rainfall of 11-20cm. Vadakara had recorded 15cm of rain on Sunday. Several districts including Kollam, Ernakulam, Idukki, Thrissur, Malappuram, Kannur, Kasaragod will receive isolated heavy rainfall.
Three shutters of Malankara dam were opened at 40cm each as the water level was at 40.32m against the full reservoir level of 42m. While at the Bhoothathankettu reservoir, five shutters remained opened at 50cm each. Other than Vadakara which received the state’s highest of 15cm, Quilandy (Kozhikode) got 9cm while Thiruvananthapuram city and airport, Kannur, Mavelikkara and Ponnani got 5cm each. Kayamkulam got 4cm of rainfall.
IMD has also predicted the possibility of a thunderstorm with lightning and wind speed reaching 40kmph accompanied by moderate rainfall is very likely to occur at one or two places in Thiruvananthapuram, Kollam, Ernakulam, Thrissur, Kozhikode, Malappuram, Kasaragod and Kannur districts.