The Kerala State Disaster Management Authority on Thursday evening issued an orange alert in Kollam, Alappuzha, Ernakulam and Thiruvanathapuram district on June 10. The KSDMA said there was a possibility of heavy to very heavy rainfall, between 115 mm to 204.5 mm, in these places.

The KSDMA also issued an orange alert for Kollam and Alappuzha districts for June 9, a yellow alert for seven districts on the same day, and for five districts on June 10. An “orange alert” is usually issued to forecast extremely bad weather, warning citizens to be prepared for evacuation. A “yellow alert” indicates severely bad weather over a number of days.

The India Meteorological Department in its 8 pm bulletin on Thursday forecast that the southwest monsoon will hit Kerala within 48 hours. “An off shore trough is very likely to develop around 8th June, off Maharashtra coast to Kerala coast,” the Met department said. “In association with these favourable conditions, Southwest Monsoon is very likely to set in over over Kerala during next 48 hours.”

There has been good rainfall over Kerala and coastal Karnataka and parts of Lakshadweep Islands during the last 24 hours, The Times of India reported late on Thursday. However, the onset of monsoon has been delayed by a week, which has caused a 70% deficiency in the rainfall in the first five days of June.

“This deficiency in the rainfall will reflect more on Kerala and Karnataka than in other states where the monsoon would have just started,” S Abhilash, associate director of ST-Radar facility, Cochin University of Science and Technology, told the daily.

The pre-monsoon season – March, April and May – ended with a rainfall deficiency of 25%, which is the second lowest in 65 years, the IMD had said on June 4. The country received only 99 mm of rainfall from March 1 to May 31.