Strong western disturbances bring North, East under wet spell

A train of active or intense western disturbances visiting North-West India and moving to the East have precipitated large amounts of excess rainfall for the country as a whole during the first 11 days of the pre-monsoon season (March 1 to 11).

International models suggest that yet another wave of rain, snow, hail and thunderstorms may enter the North-West through the familiar Iran-Afghanistan-Pakistan route in the next five to seven days.

Widespread rainfall, snow

The India Meteorological Department (IMD) said that the latest intense disturbance has already caused fairly widespread to widespread rainfall/snowfall activity over the hills of North-West India (Jammu & Kashmir, Himachal Pradesh and Uttarakhand) during the first half of the past week (March 5 to 11).

Fairly widespread to widespread rainfall/thunderstorm has been reported from the adjoining plains (Rajasthan, Punjab, Haryana, Chandigarh, Delhi and West Uttar Pradesh) during this period. In association with this system, isolated to scattered hailstorm activity also have occurred over these regions.

Rain for Central, East India as well

The confluence between the incoming westerlies from the western disturbances with moist easterlies from the Bay of Bengal triggered fairly widespread rainfall/thunderstorm activity along with isolated hailstorm and isolated intense precipitation over parts of Central and East India, the IMD said.

Heavy to very rainfall was reported from isolated places over Telangana on one day. At the same time, it was heavy over West Uttar Pradesh on two days. East Rajasthan, Jharkhand, Himachal Pradesh and Odisha too saw heavy rain on one day during the week, and so did Tamil Nadu and Puducherry in the South.

As a result, North-West and Central India received 145 per cent and 305 per cent above the long-period average respectively during the week while the country as a whole received excess rainfall of 131 per cent.

The cumulative rainfall during so far during this pre-monsoon season (March 1 to 11), is 82 per cent above the long-period average. Details of the rainfall distribution over the four broad geographical regions of the country as below:

The US National Centres for Environmental Prediction tends to agree with the forecast for the next western disturbance and precipitation over North-West India as well as adjoining Central India from March 23 to 31.

The intervening week (March 15 to 23) may see a wet spell persisting over East-Central India and breaking fresh over the South Peninsula. Many parts of Tamil Nadu and adjoining Kerala; Andhra Pradesh, Odisha, Chhattisgarh, Jharkhand, Bengal and the North-Eastern States may benefit from this spell.