FEWS NET scientists explore new ways to forecast extreme heat 

As rising global temperatures drive heatwaves and amplify droughts, scientists with the Famine Early Warning Systems Network (FEWS NET) are developing ways to mitigate future risks and save lives. 

Over the years, FEWS NET’s international science team has worked together to provide early and accurate forecasts of extreme weather and climate. 

Beginning in March 2023, when concerns of a strong El Niño emerged, FEWS NET began anticipating below-average precipitation and above-average temperatures over Southern Africa later in the year and into early 2024. Unfortunately, recent events verified these concerns.

In a January Key Message Update, FEWS NET explained that rainfall will likely remain below average in southern and central Mozambique, Zimbabwe, southern Malawi, southern Madagascar, and southeastern Angola through the end of March. 

"We often see dry seasons that accumulate over many months and have bad outcomes, and that is something that we've developed a lot of tools to track," Dr. Chris Funk, Director of the UCSB Climate Hazards Center (CHC), said. "This season was really scary in the sense that basically, it was about 40 days of bad weather and extreme heat that rapidly emerged and just devastated crops." 

In the realm of extreme heat, the CHC team is further advancing its temperature monitoring and forecasting technologies by implementing a "staged" early warning system, including the Climate Hazards Center InfraRed Temperature with Stations (CHIRTS), CHIRTS-ERA5 (European Centre for Medium-Range Weather Forecasts Re-Analysis, version 5), and CHIRTS-GEFS (Global Ensemble Forecast System) products. 

CHC scientists are currently incorporating these CHIRTS and CHIRTS-ERA5 observations into FEWS NET's routine temperature monitoring to help translate weather and climate shocks into projected impacts on crop production levels. Once CHC researchers fully develop CHIRTS-GEFS, they plan to bring it on board. 

CHIRTS products use data from climate model simulations, meteorological stations on the ground that measure things like temperature and rainfall, and satellites that capture climate temperatures from the Earth’s surface. FEWS NET scientists use these observations to track temperatures and compare them to historical temperature recordings for the region. 

CHC researchers first created CHIRTS as a cutting-edge tool to provide high-resolution temperature estimates with hyper-localized information for FEWS NET-monitored regions. 

A new, more rapidly updated product, CHIRTS-ERA5, is also under development. Despite lacking the satellite inputs that go into CHIRTS, the CHIRTS-ERA5 dataset allows for temperature updates at faster intervals than its predecessor. With daily updates available, CHIRTS-ERA5’s rapid assessments of extreme heat prediction can support early action. 

While still under development, the National Oceanic and Atmospheric Administration (NOAA) Climate Prediction Center (CPC) Global Ensemble Forecast System (GEFS) will impel CHIRTS-GEFS temperature forecasts. 

The CHC is designing the CHIRTS-GEFS forecast system to track heat risks at high resolutions, making the forecasts useful in heavily populated urban areas and areas where agricultural production is vital for both lives and livelihoods. Further development is on the horizon, but these emerging resources will be helpful when they are ready.

The long-term vision for CHIRTS technology is to establish a stream of temperature products similar to the CHC's CHIRPS rainfall products as an integrated monitoring system. FEWS NET scientists plan to apply this technology worldwide. 

"The good news is that we are very much in the process of developing systems to monitor and interpret these shocks," Funk said. "Both NOAA's Climate Prediction Center and the UCSB Climate Hazards Center recognize these risks and are working to monitor and anticipate them." 

In an ongoing effort to implement heat-health early warning systems in Africa, NOAA scientists are experimenting with machine learning to enhance existing forecast technologies. 

To ensure these forecasts are actionable, NOAA works closely with meteorological services, partners, and stakeholders, including the Ministries of Health and other institutions, to translate excessive heat into health impact risks. NOAA provides these forecasts to meteorological services, which map this critical information into existing heat vulnerability data to produce health impact outlooks. 

This mapped information more easily identifies and classifies at-risk areas as high- or moderate-risk for people living in that region. 

“Many people are not aware of the risks they take with prolonged exposure to sunlight and heat," Dr. Wassila Thiaw, NOAA CPC research meteorologist and International Desk team leader, said. "Whether they are trading in the markets or working in the field, they do not necessarily take the precautions they need to reduce risk of illness." 

NOAA scientists work with countries and use this excessive heat-related data to create an experimental Heat Health Early Warning (HHEW) Bulletin that describes regional health conditions and provides impacted groups with preventative actions to mitigate the effects of excessive heat on human health. 

Although the HHEW bulletin is still under development and not yet publicly available, the CPC hopes to collaborate with partners to launch it into operations next year.

The Multidisciplinary Working Group on heat-health plans to disseminate the bulletin to local authorities, governments, community organizations, and the media so decision-makers can take informed, early action. 

NOAA researchers expect to improve heat hazards outlooks through machine learning forecasts, which will ultimately improve the health impact forecasts by providing more accurate insights and raising awareness of potential heat-health risks.

"We have to bring governments to really understand that this is a low-hanging fruit for saving people's lives and to move toward developing national action plans for heat-related illnesses," Thiaw said. 

Advanced technologies and strong adaptation practices unlock promising potential

In addition to recent and future technological innovations, FEWS NET scientists are promoting adaptation practices to help mitigate the impacts of extreme heat. 

"If we think that there's going to be three days of really extreme heat, and you are working with meteorological agencies and health officials in a country, you have an opportunity to get critical risk information to the right cities at the right time," Funk said. “I'm hopeful that some of the worst impacts of these rapidly emerging human heat risks can be adapted to."

With scorching temperatures taking their toll on plant life significantly earlier in the season, micro-irrigation can help plants establish themselves, overcoming the impacts of warmer temperatures, if farmers have enough early warning to take action to adapt their agricultural practices. For example, last year, CHC researchers collaborated with the Kenya Meteorological Department to predict and track heavy rains. A media group, Shamba Shape Up, disseminated videos to farmers that described how to dig water retention pits, saving water for later use. Another preventative measure involves digging a pit and planting a crop in the middle, which helps retain moisture and fortify the crops against heat stress. 

"The goal is to take all of the fantastic products that FEWS NET has developed and make them available to our friends in the global South where they can proactively improve their risk mitigation activities," Funk said. "That is definitely the future, and it's a future that we are already working hard to build today." 

Subscribe to FEWS NET updates to receive agroclimatology and food security forecasts directly in your inbox, and follow FEWS NET on X (formerly known as Twitter) and Facebook for the latest updates.