Temporary relief from cold wave likely for north-west

India Meteorological Department (IMD) has warned that cold wave conditions would prevail over isolated pockets of Punjab and Haryana for another 24 hours (Saturday).

Cold day conditions are expected to continue over Uttar Pradesh during the next two days as well, it said in its bulletin issued on Friday.

There have been warnings of fog or dense fog in east Uttar Pradesh, Bihar, sub-Himalayan West Bengal and Sikkim during this period.

SOME RESPITE

Northwest India, however, can look forward to some respite as cold northwesterlies might be replaced by the warmer southwesterlies associated with a feeble western disturbance strolling into the region from Sunday.

A feeble western disturbance is classified as such given its lesser sweep and magnitude, which robs it of the potential to carry moisture required to generate secondary cyclonic circulations.

These circulations are known to cause light to moderate showers if supplemented by residual moisture from the closest seas (the north Arabian Sea, which the western disturbance passes over).

These showers propagated from the northwest and adjoining east are in line with the movement of the causative circulation and the parent western disturbance.

The token presence of moisture, which does not fall as rain, is enough to cause fog or dense fog over the plains especially on days when low-level winds are conspicuous in their absence.

This is exactly the scenario that the IMD is seeking to depict as emerging over northwest India and east India – cold over the next 24 hours over northwest before getting slightly warmer.

DENSE FOG

Dense fog has already been reported from most parts of Uttar Pradesh, Bihar, Sub-Himalayan West Bengal and Sikkim.

Foggy to densely fog conditions are expected to hang over Uttar Pradesh and Bihar for two more days as it would take as many days for the western disturbance to transit these regions on its eastward journey.

But the movement away of the westerly system would only clear the way for colder northwesterlies to fill the plains of the north-west and bring down the mercury appreciably to trigger cold wave conditions yet again from next Tuesday.

On Friday, minimum temperatures were below normal by 2 to 4 deg Celsius over parts of Punjab, Haryana, Madhya Pradesh and Chhattisgarh.

Cold wave conditions continue to prevail over isolated pockets of Punjab and Haryana. The lowest minimum temperature of -0.6 deg Celsius was recorded at Adampur in Punjab.


Maximum temperatures too were below normal over Haryana, Uttar Pradesh, Madhya Pradesh, Bihar, Jharkhand, the North-Eastern States, Punjab, north Maharashtra, Chhattisgarh and West Bengal.

In the south, isolated rainfall may occur over extreme south peninsular India during next three days, the IMD said in its forecast. A trough lay extended from the Lakshadweep area into the mainland but convection had been reduced with the required sea-surface temperature regime getting confined to a narrow stretch.

Isolated rain or snow has been forecast over the western Himalayas from Sunday onwards in association with the arrival of the western disturbance.