India Meteorological Department (IMD) has predicted heavy rainfall over Arunachal Pradesh, plains of West Bengal, Bihar, Jharkhand, Odisha and Coastal Andhra Pradesh on Thursday as monsoon showed signs of revival. Heavy to very heavy rainfall with extremely heavy falls is likely over the hills of West Bengal, Sikkim, Assam and Meghalaya.
Revival in South
Squally winds speeding to 45-55 km/hr and gusting to 65 km/hr may prevail over West-Central and South-West Arabian Sea and the Gulf of Mannar. Similar winds are are also predicted along and off Kerala-Karnataka coasts, the Lakshadweep area, South-West and adjoining South-East Bay and along off the Tamil Nadu-South Andhra Pradesh coasts. Fishermen are advised not to venture into these areas.
Anchoring system absent
This represents a broad-based strengthening of the current along the usual routes in both the Arabian Sea and the Bay of Bengal, but it will need a cyclonic circulation to anchor and drive up to the heights and draw out rain. There is hope that one such would materialise over the Odisha-Bengal coasts over the next three-four days, as depicted in IMD’s short-term numerical model projections.
Cyclonic circulation seen
This cyclonic circulation is forecast to take the most suited track over land towards East-Central India and North-West India gathering strength along the way. It is believed that this West-North-West track will allow the rains to expand into the monsoon core regions over Central and North-West India.
If proven true, it would mark a decisive break from the lull brought in the wake of the erstwhile cyclone Biparjoy whose remnant is still active over land in Central Uttar Pradesh close to two weeks after genesis in the Arabian Sea. It took the sails out of the monsoon after it made a weak and delayed onset on June 8. The kinetic energy lost in the process is being made good as it enters the last 10 days of June.
All-India rain deficit
The all-India rain deficit as on Wednesday (June 21) stood at -33 per cent with Gujarat, Rajasthan, Punjab, Himachal Pradesh and Jammu and Kashmir receiving non-seasonal surplus from a rampant Biparjoy while Tamil Nadu (+13 per cent) in the South Peninsula; hills of West Bengal and Sikkim (+23 per cent) in the East too made gains from localised heavy rain during the period.