Although the wind pattern and the cloud conditions were fulfilled setting the stage for a slightly early advent of the monsoon, it was only on Wednesday that the rainfall was sufficient to warrant confirmation of the arrival of the monsoon, V K Gangadharan, Director, Meteor-ological Centre, Thiruvanant-hapuram told FE.
Depression in the Arabian Sea moving in a northwesterly direction is the first pointer to the arrival of monsoon. Starting from May 10, if at least five out of ten meteorological stations in Kerala report 24-hour rainfall amounts of 1 mm or more for two consecutive days, the monsoon is declared on the second day. If three or more out of seven stations in Kerala report no rainfall for the next three days, a temporary recession of the monsoon is indicated.
According to Mr Gangad-haran, all signs point to the monsoon actively spreading to the North Kerala in a couple of days. The South West Monsoon is expected to move to Mangalore in four days, sweep Maharasthra and the Gangetic West Bengal in the next five days, cover the Delhi latitude by June and then reach Rajasthan. On Sunday, the Meteorological Centre, Thiruv-ananthapuram had predicted the breaking of the monsoon in the next 72 hours.
Kerala is expected to get 215 mm rainfall in the monsoon season. This is 99 per cent of the states usual share, Mr Gangad-haran said.
According to the IMD director in Delhi, Dr HR Hatwar, after the onward march of the monsoon was halted since May 18, peculiar conditions developed on May 28 which advanced the monsoon to cover southern parts of the Arabian Sea and more parts of southwest and east central Bay of Bengal. FE had earlier reported that monsoon system was halted since May 18 and was unable to enter Sri Lanka.
The monsoon entered Sri Lanka on May 28, three days later than the scheduled date, causing showers in the western, southern, central and Sabaragamuwa provinces. The wind speed was between 15 and 30 km per hour with westerly to southwesterly direction. The wind speed is expected to increase to 40 to 50 km per hour over southern and western coasts of Sri Lanka.
The northern limit of the monsoon on May 29 lay at five points - 10 degree north latitude and 60 degree east longitude, 10 degree north latitude and 70 degree east longitude covering Kochi and Nagapattinam, 13 degree north latitude and 86 degree east longitude, 17 degree north latitude and 93 degree east longitude and 18 degree north latitude and 95 degree east longitude.
The IMD has said that conditions are favourable for further advance of the monsoon into northern parts of Kerala and Lakshadweep during the next 48 hours.
The monsoon entered the southern part of Anandam & Nicobar Islands on May 14, a day earlier than the scheduled and covered the entire island segment by May 18. Thereafter the monsoon system bacame static and revived on May 28.
In Kerala, the state government has an arrangement with the Thiruvananthapuram Meteorological Centre by which crop experts and weather scientists put their heads together to form an agro-meteorological advisory unit. Following the counsel of this unit last week, the state agriculture department has warned coconut, paddy and rubber farmers in the state to refrain from spraying pesticides on their farms in the next two weeks.