Tuesday, March 09, 2010

Westerlies seen capping heat until March 20

International weather models are of the view that western disturbances would keep rolling in, one after the other, to extend their calming influence on weather over north-west India until March 20, if not beyond.

India Meteorological Department (IMD) said, in its outlook on Monday, that a “feeble western disturbance” may check into the region around Friday.

The European Centre for Medium-Range Weather Forecasting (ECMWF) seems to suggest that a weak system might already be impacting the region.

Strong system

This will be followed by a relatively stronger system by Wednesday/Thursday, which would be active for a day or two. Passage of the system to the east would let in strong north-westerly to westerly currents for the next few days.

According to the ECMWF, a much stronger system, an exceptionally strong one at that, might break into the region from March 16. The system is shown spinning up a low-pressure area the very next day, which could go on to become even a depression, over Rajasthan. This could potentially throw up the threats of heavy rains, high wind and hail to the standing wheat crop in the north-west.

On Monday, strong north-westerly to westerly winds were prevailing over parts of the Indo-Gangetic plains, the IMD update said.

Minimum temperatures were above normal over many parts of Gujarat, east and central India, some parts of peninsular and northeast India and isolated pockets of East Rajasthan.

Maximum temperatures, too, were above normal over many parts of Himachal Pradesh, Uttarakhand, Chhattisgarh, Vidarbha, and east, north-east and peninsular India.

Cloud imagery

Satellite imagery on Monday showed the presence of low to medium clouds (partly cloudy conditions) over parts of western Himalayan region and the north-eastern States.

Isolated rain or thundershowers are likely to occur over parts of the north-eastern States during the next three days. A fall in minimum temperatures is expected over parts of northwest and adjoining central and east India.

A fall in maximum temperatures also is expected over parts of north-west and adjoining central and east India during this period.

Rains for south

Forecast until the weekend said that isolated rain or thundershowers are likely over the Andaman and Nicobar Islands, Arunachal Pradesh and extreme south peninsula. Isolated rain or snow would occur over western Himalayan region.

The trough or wind discontinuity from Orissa to south Tamil Nadu through interior Andhra Pradesh persisted on Monday. An outlook from the Chennai Regional Met Centre said that isolated rain or thundershowers may occur over Kerala and interior Tamil Nadu, over the next two days.