Climate Change making Weather prediction difficult

• IMD Director General recently stated that climate change has made weather prediction a difficult task for the forecasting agencies

• A recent Standford University study has found that rising temperatures could have an impact on weather prediction

• Another study from Stockholm University has found that the ongoing climate changes make it increasingly difficult to predict summer rainfall

• There is a need for localized forecasts and improving the detection plus real-time monitoring of weather events

• IMD has announced recently that it is planning to meet the challenges of climate change in terms of weather prediction by strengthening its observational network

Recently the Indian Meteorological Department (IMD) Director General stated that climate change has made weather prediction a difficult task for the forecasting agencies to accurately predict severe weather events. Director Mrutyunjay Mohapatra said that ‘weather bureaus across the world are focusing on augmenting the observational network density and the weather prediction modeling to improve predictability.’ Mohapatra further said that the IMD is thus installing more radars and upgrading its technology to meet the challenge. 

How Climate Change could make weather harder to predict

A recent Stanford University study has found that rising temperatures could have an impact on how far meteorologists can see into the future. The study has pointed to the fact that warmer climates are harder to predict than colder climates. Thus predicting weather in an increasingly warmer world owing to climate change could prove to be harder. 

“It seems that colder climates are just inherently more predictable than warmer ones,” Aditi Sheshadri, an atmospheric scientist at Stanford University and also the lead author of the study said to The Washington Post.

The study focused on the middle latitudes, which included the United States, Europe and China. It was found that, in warmer climates, storms grow more quickly and errors happen faster. 

“The new research, based on computer simulations of a simplified Earth system and a comprehensive global climate model, suggests the window for accurate forecasts in the midlatitudes is several hours shorter with every degree (Celsius) of warming. This could translate to less time to prepare and mobilize for big storms in balmy winters than in frigid ones,” said a report on the study. 

“For precipitation, predictability falls by about a day with every 3 C rise in temperature. The effect is more muted for wind and temperature, with one day of predictability lost with each 5 C increase in temperature,” the report further mentioned. 

Another study from Stockholm University has found that the ongoing climate changes make it increasingly difficult to predict certain aspects of weather like the volume of summer rainfall. The decrease in the temperature difference between the North Pole and the equator is a major factor, the study concluded.

The study, focusing on weather forecasts in the northern hemisphere spanning 3-10 days ahead found that the greatest uncertainty is regarding summer rainfall. This is vital in terms of our ability to predict and prepare for flooding in countries like India. 

“Reliable weather forecasts are tremendously important for almost all of society, and summer flooding in the northern hemisphere especially is one of the great challenges as the climate is getting warmer,” says Sebastian Scher, the main author of the study. “It is very important that meteorological institutes around the world are given the opportunity to develop their tools and methods as conditions change.”

A doctoral researcher in the Department of Meteorology, University of Reading, UK explained to The Indian Express in an interview, “…climate change is making certain aspects of weather forecasting challenging. Of course, the most visible impact of global warming is on temperature (e.g., increasing frequency, intensity and duration of heatwaves). However, models do a decent job at predicting temperatures than predicting rainfall. We know that global warming can intensify extreme rainfall events, thereby increasing the risk of hydrological disasters.”

He further stressed the need for localized forecasts and improving the detection plus real-time monitoring of weather events.  

“In India, we do not need such forecasts for temperatures, but rainfall forecasts specific to an administrative ward will certainly benefit everyone. However, producing such a local-level forecast could be a challenging and costly task. Moreover, such forecasts need to be accurate; otherwise, there will be a lot of inconvenience due to false alarms,” he added. 

Meeting the challenge

The Indian Meteorological Department has announced recently that it is planning to meet the challenges of climate change in terms of weather prediction by strengthening its observational network with the ‘augmentation of radars, automatic weather stations and rain gauges and satellites to improve predictability’.

According to reports, ‘its forecast accuracy has improved by about 30 to 40 percent for severe weather events like cyclones, heavy rains, thunderstorms, heat waves, cold waves and fog in the last five years due to an improvement in the observational network, modeling and computing systems of the IMD and the Ministry of Earth Sciences (MoES)’.

The IMD Director said that the accuracy of heat wave forecasts is 92 percent while heavy rainfall forecast accuracy at the sub-divisional level has improved to 79% at present from 60% five years ago.

Use of radars

Radars are preferred for accurate weather prediction because they have a higher resolution. They can also provide observations after every 10 minutes.

“We have put up six radars in the northwest Himalayas and four more will be installed this year. The procurement process is on for eight radars in the northeast Himalayan region,” Mohapatra said “There are certain gap areas in the rest of the country that will be filled up with 11 radars. The number of radars will increase from 34 at present to 67 by 2025”.

Localized forecast 

The MoES also plans to upgrade its computing system which will help in assimilating more data into the model so that it can then be run at higher resolutions.

The present, resolution of the IMD/MoES weather modeling system is 12 km and the target is to make it 6 km. In the same way, the resolution of the regional modeling system will be upgraded to 1 km from 3 km.

The lower the range of a weather model, the higher its resolution. Greater precision can be achieved by higher resolution. 

“We are providing forecasts up to the district and block levels currently. Going ahead, we will provide forecasts up to clusters at the panchayat level and specific locations within cities,” Mohapatra further said.