Hot
Weather Conditions over Northwest and Central India
The pre-monsoon season in India comprising of the months
of March, April and May is also popularly known as Hot Weather or Summer Season. The temperatures, particularly the maximum, during
this season are very high over most parts of country especially over central
and northwest India. The maximum temperatures when become 4-5°C above normal are
called as heat wave conditions causing heat discomfort. During this season,
northwest & adjoining central India is usually affected by dust storms
locally known as ‘ANDHI’ and also by dust raising winds adding to the
discomfort. The eastern parts of the country are affected by violent storms called
Norwesters (popularly known as Kal
Baisakhis) during this season.
During the April 2008, maximum temperatures were
considerably below normal during 1st week and nearly normal in the second
week. However, there was gradual increase in the maximum temperatures during the
2nd fortnight over most parts of northwest and central India. The
mean maximum temperatures during the period 17-23 April were 40-42°C over
central and isolated pockets of northwest India. They were above normal by
2-4°C. However, during the last week (24th -30th April), this
zone of high temperatures extended northwestwards covering most parts of central
& northwest India. The mean maximum temperatures became 42-44°C, which were
3-5°C above normal. Some of the stations
recorded maximum temperatures even in excess of 45°C on a few days. Heat wave conditions also prevailed over
isolated pockets of Madhya Maharashtra, Vidarbha,
Madhya Pradesh, Uttar Pradesh, Rajasthan, Haryana, Delhi, Chandigarh, Punjab,
Himachal Pradesh, Jammu & Kashmir and Uttarakhand on some days during this
period.
This phenomena of continuous hot
weather conditions over northwest & central India during 2nd
fortnight of April was mainly due to the absence of any significant thunderstorm
activity over the entire region and also due to advection of heat from west caused
by prevailing northwesterly winds. The rainfall and temperature scenario
including heat wave conditions is given in figures 1-3 and
tables 1-2.
Weather
Forecast for the next one week
The current meteorological analysis and interpretation of available Numerical Weather Prediction models suggest that mainly hot weather with maximum temperatures above 40°C is likely to prevail over northwest & central India. Some of the areas are also likely to experience heat wave conditions during next 3 days. However, in view of likely thunderstorm activity during 5th-7th May, a temporary respite from hot weather conditions is expected.
Fig-1:
Mean Maximum Temperature and departure during 17-23 April 2008
Fig-2:
Mean Maximum Temperature and departure during 24-30 April 2008
Fig 3: Rainfall
during the week 17-23 and 24-30 April 2008