Extended reign of N-E monsoon drawing to close

The India Meteorological Department (IMD) has said that conditions are becoming favourable for cessation of the North-East Monsoon rains over Tamil Nadu, Puducherry, Karaikal, Kerala, Mahe and adjoining areas of Coastal Andhra Pradesh, Yanam, Rayalaseema and South Interior Karnataka from Tuesday.

Weather blogger @ChennaiRains notes that January 2021, has become the wettest (133.9 mm) for Tamil Nadu and Puducherry in a century. The wettest January till now has been in 1921 with 141.2 mm. The region has received as much as two-thirds of the average rains for the first six months of the year already. This is also only the sixth time since 1901 when January rains have crossed 100 mm here.

Wet spell set to return

Tamil Nadu received 959 per cent more than the normal, while it was 746 per cent for Puducherry. The overall rain surplus for the country as a whole, during the first two weeks of January (January 1 to 13), is at 95 per cent with North-West India and the South Peninsula being runaway beneficiaries. Central India, too, has done reasonably well; while East and North-East has drawn practically nil rain during the period.

An extended forecast by the IMD for the next two weeks suggests that the region would remain largely dry during the week from January 22-28 but normal to above normal rain would return during the subsequent two weeks (January 29 to February 4 and February 5-11). A number of global models are also suggesting the same, with an unlikely low-pressure area thrown in for good measure.

Wind shifts direction in North

As for North-West India, winds have shifted to being easterly over the plains. Reversal of winds to westerly/northwesterly would take place from late on Monday night as a western disturbance marches in, bringing down night temperatures by 2-4 degrees Celsius during next three days, the IMD said.

This could also trigger cold wave conditions over parts of East Uttar Pradesh, Punjab and Haryana, Chandigarh and Delhi until Wednesday, and over West Uttar Pradesh and North Rajasthan from Tuesday to Thursday.

Dense to very dense fog

Dense to very dense fog may envelop parts of Punjab, Haryana, Chandigarh, Delhi, Uttar Pradesh, North Rajasthan, Bihar and Odisha until Tuesday morning and reduce in spread and density thereafter till Friday. Cold day (with maximum temperatures at 16 degrees Celsius or below) conditions may set in over parts of Punjab, Haryana, Chandigarh, Delhi, Uttar Pradesh and Bihar during the next two days.

The western disturbance may interact with low-level easterlies from Saturday, sparking off scattered to widespread rain/snow over the hills of North-West India until Sunday and isolated rain/thundershowers over the adjoining plains of North-West India on Saturday and Sunday, the IMD added.