Spring, summer may be warmer: WMO
NEWDELHI: Average temperatures are expected to be above normal in most parts of the world, including India, between March and May, the World Meteorological Organisation (WMO) warned on Monday.
Warmer than usual temperatures are expected even without the presence of El Niño, a global weather phenomenon characterised by warm ocean temperatures in the equatorial Pacific Ocean.
El Niño also causes droughts in many parts of the world (and affects the monsoon rains in India). WMO said that there is a 60% chance of ongoing El Niño neutral conditions to continue for the next few months; and there is a 55% possibility of it remaining neutral in the June to September period.
The WMO said above-average sea surface temperatures are likely to rise both in the tropics and extra-tropics. “The forecast for March to May leans towards above-normal land temperatures, particularly at tropical latitudes. The global warming trend is also contributing to above-average sea surface and air temperatures,” it said.
Maps shared by the WMO -- on the forecasts of surface air temperature and rainfall for the March to May season -- indicate that the country’s western coast will be impacted significantly by above-normal average temperatures, while the rest of the country will also experience warmer than usual air temperature. The precipitation map shows below normal to normal rains in India.
“Even El Niño-southern Oscillation neutral months are warmer than in the past, as air and sea surface temperatures and ocean heat have increased due to climate change,” said Petteri Taalas, secretary-general, WMO.
“With over 90% of the energy trapped by greenhouse gases going into the ocean, ocean heat content is at record levels. 2016 was the warmest year on record, as a result of a combination of a strong El Niño and human-induced global warming. 2019 was the second-warmest year on record, even though there was no strong El Niño effect. We just had the warmest January on record. The signal from human-induced climate change is now as powerful as that from a major natural force of nature,” he added.
India Meteorological Department (IMD), in its seasonal forecast for the pre-monsoon or summer season, said last Friday that average temperatures are likely to be warmer than normal over most sub-divisions of northwestern, western and central India and some parts of peninsular India. The forecast for the March to May season said that abovenormal heatwave [HW’] conditions are likely to persist in the core HW zone.
The season’s average maximum temperature is likely to be warmer than normal by less than 1 degree Celsius over Himachal Pradesh, Uttarakhand, West Rajasthan and Arunachal Pradesh. It is also likely to be warmer than normal by -0.5 degree Celsius to 1 degree Celsius over Uttarakhand, the IMD said.
Above-normal rains are expected north of the equator in the central tropical Pacific and south-western Indian Ocean extending into eastern equatorial Africa. Elevated probabilities of below-normal rains are over much of the rest of the western tropical and extratropical Pacific. Below-normal precipitation is also likely for northern South America, Central America, the Caribbean and southern Africa, according to WMO’S Global Seasonal Climate Update. An outlook for persistent dry conditions in these sub-regions suggests that they should be closely monitored in the coming months, the WMO said.
“Above-average surface air temperature is not linked to El Niño or global warming every time. Though global warming is causing a rise in average temperatures in most years, there is year-on-year variation. Day-today factors such as clear sky, moisture etc also have an impact which is why we are going to see some days with maximum temperatures considerably above normal and on some days below normal depending on local factors. The overall rise in average temperature is lower than what we are experiencing globally. In 2016, we recorded the highest rise in average temperatures of .71 degree Celsius compared to preindustrial levels, while the annual global temperature last year was 1.1 degrees Celsius warmer,” said DS Pai, senior scientist, IMD Pune.
In India, a fresh western disturbance is likely to affect western Himalayan region and plains in the north-west from Wednesday. Fairly widespread to widespread rainfall or snowfall is likely to occur over the region between Thursday and Saturday. It is also likely to cause rainfall over Punjab, Haryana, Chandigarh, Delhi and Uttar Pradesh.