Tuesday, January 8th 2013, 5:12 PM EST
Continue the unusual cold spell that for more than two weeks is hitting the states of northern India and much of northern Pakistan, where a number of records have fallen overall in important cities like Lahore. But the more discomfort you are suffering in northern India, where the great cold of these days has caused the death of dozens of people, mostly homeless and beggars. Most of the victims was registered in the state of Uttar Pradesh, where the minimum temperatures fell to near 0 ° C.
The authorities have ordered the closure of schools, which are without heating. The bad weather is tightening siege also about 20 million people in New Delhi, the great capital of modern India. The station in New Delhi last week recorded the coldest day of the last 44 years, with a minimum temperature dropped to +3 ° C only. Still far from the record absolute minimum of -0.6 ° C. A thick blanket of fog has caused severe disruption to rail and air traffic. The Big Chill these days besieged the great plains of northern India is produced by these extensive fog banks, baked by the strong temperature inversion induced robust dynamic Tibetan anticyclone, which has shifted its focus on India north, with maximum baric over the 1020 hpa.
In recent weeks, over the great plateau of Tibet, he settled a block of very cold air and heavy that it has remained almost stationary in the north of the Himalayas, in a context in anticyclonic share. The dry air, together with the lack of ventilation in the lower layers and the total serenity of heaven, facilitates the formation of strong temperature inversion layers near the ground that favor the formation of these dense fog radiation above the plains of ' northern India. Mists, sometimes so thick, causing drastic reductions in visibility, practically blocking the road and rail traffic in the already chaotic metropolis in India.
But the powerful Tibetan anticyclone, with its particular placement is attracting quite cold air masses in the lower and middle strata of the Himalayan regions are poured over the plains states of North India. These pulses cold northerly winds tend to match the dense smog that envelops the great cities of the Asian country, preventing sunlight for most of the day. The significant reduction of sunshine daytime, already at the annual minimum in the month of January, tends to further cool the layers of air present in the vicinity of the soil.
This favors this abrupt cooling of the column of air near the ground, where the humidity stagnated tends to condense with the usual formation of dense mist and fog banks (thin layers based at the ground), while going high masses air tend to become milder, with values often above +10 ° C +12 ° C at 850 hpa (about 1300-1400 meters). Until there will be a greater mixing of air masses existing in the intermediate and lower layers of the states of northern India continue to deal with these extremely low temperatures, even next to +3 ° C +1 ° C.
Meanwhile, due to the strong temperature inversions in India was recorded the first record of this 2013. After an avalanche of absolute record heat finally one of them will fall to the cold. In Kanpur, northern India, was recorded a minimum temperature of -1.1 ° C well, the lowest ever since the existence of the survey.
The -1.1 ° C in Kanpur beat the previous record of -0.9 ° C, dating back to December 27, 1961. Of course it is a weak cold of historical significance for the town, never dropped below -1.0 ° C over the last decades of surveys. Even more remarkable the -3.0 ° C stable two days ago from Narnaul, where it was stored on the first record cold of 2013. But among the lower minimum should be reported, also in India, too, the +5.7 ° C of Anandpur Sahib, Chandigarh +6.5 ° C, +7.4 ° C in Amritsar, Ludhiana and +9.5 ° C to +11.0 ° C Patiala. Really very important values that are unlikely to be re-adjusted.
Some record lowest maximum ever were well beaten on neighboring Pakistan, just to the east, with an exceptional collapse of the thermal values during daylight hours. Among the lower maximum is reported that the city of Lahore. Here as well as on the plains of northern India, the big chill is originated from the strong temperature inversion in the lower layers, linked to the powerful sub-tropical anticyclone who reigns over the Indian sub-continent. Inversions produce, in the lower layers, extended fog that prevent the sun to warm the soil, keeping the temperature even below +12 ° C +10 ° C in the daytime.
Yesterday Peshawar, for example, has been wrapped by the fog and the maximum and collapsed about +10 ° C. Much lower than that of Islamabad, the capital of Pakistan, which is slightly higher. What is affecting the north of Pakistan and India is a kind of very dry and cold anticyclonic incapable of giving rise to snow events attended by reversing only the cold layer near the ground. At most, weak frosts caused by high insolation night can produce choreographic "bragged" that these parts are a true rarity.
The strong inversions with the associated radiation fog continue to affect northern India and northern Pakistan for most of the week, at least until Saturday and Sunday. Between tomorrow and Friday, the cold should move back to the east, again involving Calcutta, with resentment to Nepal and even Bangladesh on the west, where the air is very dry slips from the mountainous eastern Himalayas.