Brace for very hot days and warm nights in NW India this summer
The entire Indo-Gangetic Plains (IGP) region, including Haryana, Chandigarh, Delhi and Uttar Pradesh, is likely to experience both hot days and warm nights during the March to May season, according to India Meteorological Department’s seasonal outlook for the pre-monsoon season on Monday.
Above-normal seasonal maximum and minimum temperatures are likely over most subdivisions of north, northwest and northeast India, few subdivisions of the eastern and western parts of central India and few coastal subdivisions of northern peninsular India according to the outlook. Below-normal maximum temperatures are likely over some subdivisions of the southern peninsula and adjoining central India.
Over the IGP region, there is a 60% to 70% probability that maximum temperatures are likely to be 0.56 to 0.71 degrees Celsius above normal while minimum temperatures are likely to be about 0.12 degrees Celsius above normal. There is a 70% to 100% probability that maximum temperatures in Odisha, Chhattisgarh and the Konkan region in the west coast will be 0.66 to 0.86 degrees Celsius above normal.
The probability forecast for minimum temperatures indicates that above-normal minimum temperatures are likely over most of the subdivisions of north India along the foothills of Himalayas, northeast India, western part of central India and, and southern parts of peninsular India. Most of the subdivisions of east and adjoining central India, and few subdivisions of extreme northern part of the country are, however, likely to experience below-normal minimum temperatures.
Interestingly, the outlook also states that currently, moderate La Niña conditions are prevailing over the equatorial Pacific, and sea surface temperatures (SSTs) are below normal over the central and eastern equatorial Pacific Ocean. The latest Monsoon Mission Coupled Forecasting System (MMCFS) forecast indicates that La Niña conditions are likely to sustain during the upcoming hot weather season from March to May.
“Yes, La Niña has a cooling influence but La Niña is not the only factor that the model considers. There is climate change and other variations which can impact weather. So even if La Niña conditions are moderate, it doesn’t necessarily mean a less warm summer. Frequency of heat waves is likely to be higher in northwest India, Odisha, Jharkhand, Gujarat, Konkan, etc. We also have to remember that this model only gives us an average for the season. There can be large day-to-day variations which will be highlighted in IMD’s daily forecasts,” explained DS Pai, senior climate scientist at IMD, Pune.
El Niño and the Southern Oscillation (ENSO) is a periodic fluctuation in sea surface temperature and the air pressure of the overlying atmosphere across the equatorial Pacific Ocean according to the National Oceanic and Atmospheric Administration (NOAA).
ENSO has a major influence on weather and climate patterns such as heavy rains, floods and drought. El Niño has a warming influence on global temperatures, whilst La Niña has the opposite effect. In India for example, El Niño is associated with drought or weak monsoon while La Niña is associated with strong monsoon and above-average rains and colder winters.
IMD is preparing new policies for better preparedness during summer. It will issue heat wave warnings valid up to five days daily which will be updated by the national weather forecasting centre. Impact-based heat wave warning will also be issued wherein the general public is advised how to protect themselves. For example, if a severe heat wave is likely to persist for more than two days or total number of heat wave days are likely to persist for over six days then extreme care will be suggested for vulnerable people. There will be a high likelihood of developing heat illness and heat stroke among all age groups during such conditions. IMD will also provide meteorological support to states and districts for preparation of heat action plans. A GIS-based web page has been created for heat wave warnings.