With weak La Nina, January this year third warmest since 1901: IMD

Meteorologists attributed multiple factors for a warm January, which is normally dominated by cold waves to severe cold waves and cold day conditions. The weak phase of La Nina — the abnormal cooling of the sea waters along the equatorial Pacific Ocean — is one of the reasons why the cool weather evaded large parts of India last month. Moreover, southerly or easterly winds there prevailed for several days.

During the winter season, precipitation (rainfall and/or snowfall) over the plains of the Northwest and the hills of North India is mainly caused by the passing streams of western disturbances — the eastward propagating wind bands that carry moisture. Last month, seven streams of Western Disturbances moved across north India.

“But most of these Western Disturbances remained devoid of moisture being pumped in from the Arabian Sea, hence there was below normal rainfall or snowfall along the western Himalayas, covering Uttarakhand, Himachal Pradesh and Jammu and Kashmir,” said Mrutyunjay Mohapatra, Director General, IMD.

Only during a handful of days, rain and snowfall were realised over North and Northwest India leaving January largely dry. IMD’s rainfall statistics for last month showed that the country received 72 per cent below-normal rainfall. The most rainfall-deficient regions were central India ( -96 per cent) and northwest India (-80 per cent).

The Met Department has forecast a warm February over most parts of the country this year, with both maximum and minimum temperatures expected to remain above normal. This is except for some parts of Eastern Gujarat and adjoining Maharashtra, West Madhya Pradesh, and adjoining Rajasthan, and North Tamil Nadu, where the minimum temperatures could remain below normal. There were below-normal cold wave conditions during the month. Climatologically, February is a dry month (average monthly all-India rainfall is 22.7 mm), and hence, the all-India rainfall forecast for the next month is below normal.

In the wake of the likely dry and warm February, IMD has warned of adverse impacts on the health of standing wheat crops. Chickpea and mustard could experience early maturity due to such weather conditions. Fruits like apples could see early bud break, affecting the yield and quality.

Neutral ENSO conditions likely during summer monsoon

With the weak La Nina conditions setting-in last month, this phase would continue till April, IMD has said. El Nino Southern Oscillation (ENSO) has a warm phase, known as El Nino whose development has been ruled out until September this year. “We expect ENSO neutral conditions to prevail throughout the June – September period this year,” said Mohapatra.