The 24 hours ending Sunday morning saw rain or snow being reported at many places over western Himalayan region, central and east India.
Among the regions which recorded light to moderate rainfall were north Madhya Pradesh, Jharkhand, Uttar Pradesh, Chhattisgarh and Gangetic West Bengal.
MERCURY DROPS
But northwest India saw minimum temperatures drop by 2 to 5 deg Celsius in Punjab, Haryana and Gujarat and isolated pockets of East Rajasthan, west Madhya Pradesh and interior Maharashtra.
This signals the fact that these border areas are now behind the eastward-bound system – importantly its low-pressure vanguard weather-head that generates rain, snow and associated warmth.
An India Meteorological Department (IMD) update on Sunday evening said that the western disturbance has been reduced to being an upper air cyclonic circulation in the upper levels.
The induced upper air cyclonic circulation, which is the principal weather-maker, was firmly entrenched in the lower levels over northwest Uttar Pradesh.
CHILL BACK
The rear of the western disturbance is marked by ‘sinking motion’ of air, higher pressure and chill provided by the northwesterly winds blowing in from across the border.
The front of the system is now influencing mainly the east of the country, which has witnessed mercury rise by 5 to 8 deg Celsius of the normal.
Among the areas being affected by associated fog or rain the most are east are north Madhya Pradesh, Chhattisgarh, Jharkhand, Orissa, Telangana, Mizoram and Tripura. Some parts of Haryana, east Rajasthan, west Uttar Pradesh and Bihar too have been affected though not as markedly.
The lowest minimum temperature of 1.8 deg Celsius was recorded at Bhatinda in Punjab in the plains of the country.
DENSE FOG
Meanwhile, a weather warning issued by the IMD said that fog to dense fog may reduce visibility over some parts of east Uttar Pradesh, Bihar and sub-Himalayan West Bengal during next two days.
Towards the northwest, cold wave conditions have been forecast during this period.
This would happen along with skies clearing up and the ‘sinking motion’ of the air brings colder air to ‘sit over’ the surface.
In this manner, minimum (night) temperatures would fall by 4 to 6 deg Celsius over some parts of northwest and adjoining central India.
RAINS FOR TN
The resulting cold wave conditions would prevail through the next three days over some parts of northwest and adjoining central India.
As for the South, the IMD has said that rain or thundershowers may break out over Tamil Nadu on Monday before scaling up.