GUWAHATI, Feb 28 – Since the dry spell is more, winter rainfall as a whole has failed to keep the surface wet, which is leading to the warm day. Moreover, as there are enough sand dunes in the form of chars over the riverbed and exposed hills are also there around the city, the dust raising gusty winds (pachowa) during the daytime have been causing the uncomfortable hazy condition, specially in Guwahati and its neighbourhood.
This is the explanation provided by the weather office for the warm day and dusty condition that have been making life miserable here. This condition is however, expected to be over within a day or two.
The weather office here has said that a cyclonic circulation over North Assam and adjoining Arunachal Pradesh with a trough aloft extending up to 3.1 kilometres above mean sea level was witnessed today. Under its influence, rain or thundershower may occur over isolated places in Arunachal Pradesh and NE part of Assam during the next 24 hours since today morning, Weather will be dry over the rest of the region during the period, said the weather office.
In Guwahati, dust covered hazy sky during the daytime and development of thunder clouds towards the evening/night hours during the next 24 hours have been predicted by the weather office today.
According to Director, Regional Meteorological Centre (RMC), H Pathak, usually, there is less rainfall in the region during the winter season as compared to the other seasons. However Arunachal Pradesh gets more rain during the winter in comparison to the rest of the region.
The effective weather system, which brings rainfall over the region are normally seen as cyclonic circulation and trough in lower level of atmosphere over Gangetic West Bengal and adjoining sub-Himalayan West Bengal, West Assam, West Meghalaya and North West Bangladesh. Such types of weather systems persist for two to three days over this region producing rainfall. But if such systems pass away within a day, rainfall cannot be expected over the region.
Frequency of such systems observed over this region reflects the frequency of rainfall here. Practically, in most part of the winter season, easterly and northeasterly winds prevail in the lower level of atmosphere, which contribute to fair weather — that is sunny days or partly cloudy sky. That means, to get rainfall over the region the weather system must change the direction of easterly-northeasterly wind to southerly/southwesterly wind, which carry moisture form the Bay of Bengal to the region.
This winter, on most of the occasions, passing away of weather systems (cyclonic circulation/ trough in lower level of atmosphere) were mainly observed. This has resulted in less amount of rainfall, leading to a practically dry winter season, said the RMC Director.
Subscribe to:
Post Comments (Atom)
No comments:
Post a Comment