• FEWS NET accurately warned of a fourth consecutive poor rainy season months in advance, highlighting the growing risk of drought and worsening food insecurity in the eastern Horn of Africa.
• Scientists developed this outlook by analyzing climate models and ocean temperature patterns, comparing current conditions with past years to understand how the rains might perform.
• FEWS NET encouraged early action, urging governments and aid groups to prepare for potential worsening drought and rising humanitarian needs.

USAID Responds to Drought Warnings in the Eastern Horn of Africa

Following a Joint Alert on exceptional drought conditions and related acute food insecurity risks in the eastern Horn of Africa, USAID announced it will provide more than $39 million in additional humanitarian aid to the region, urging other donor organizations to follow suit.

The Famine Early Warning Systems Network (FEWS NET), one of four agencies that issued the Joint Alert, has warned since late 2021 that very high humanitarian assistance needs are likely to persist in the eastern Horn of Africa throughout 2022. In a regional consultation on the March-April-May (MAM) rainy season in January, FEWS NET stressed that a below-average rainy season in 2022 is likely.

Ahead of USAID's announcement, FEWS NET urged a "no-regrets approach" in responding to a predicted fourth consecutive below-normal rainfall season and consequential increases in acute food insecurity.

FEWS NET Agroclimatologist Explains Science Behind Seasonal Rainfall Outlooks

Forecasting potential instances of severe drought and related food insecurity requires a rigorous approach to developing outlooks for seasonal rainfall performance. Senior agroclimatologist, Dr. James Verdin, explained how FEWS NET developed its seasonal rainfall outlook for the eastern Horn of Africa.

According to Verdin, averaged "ensemble" models simulate the circulation of the oceans and atmosphere, providing insight into the potential for rainfall in the months ahead. In the Horn of Africa, while models do well forecasting the performance of October-November-December rains, they are not as skillful in predicting performance of the MAM rains. However, by analyzing large-scale patterns of ocean temperatures, agroclimatologists can explain much of the variability in seasonal rainfall in the Horn of Africa.

"Ocean water is much denser than air, so it moves and changes temperature more slowly than air, making its movements and temperature changes easier to simulate," Verdin said. "The idea is to identify years in the past that had sea surface temperature (SST) patterns in the tropical Pacific and Indian Oceans similar to model forecast SST patterns, and then examine the MAM precipitation outcomes for those analog years."

This technique of comparing oceanic temperature patterns to precipitation was used to predict a fourth consecutive below-average rainfall season across the eastern Horn of Africa in MAM 2022, according to Verdin. While precipitation maps from the last 11 analog years display varied wet/dry patterns, only 2006 and 2018 showed predominantly wet outcomes.

"MAM 2022 will see an outcome with its own unique wet/dry pattern. We don't know what it will be," Verdin said. "It could look like 2006 or 2018, but it's more likely to have significant areas of drought like the other nine analog years."

Despite the uncertainty, Verdin explained that taking a "no-regrets approach" in responding to the potential for continued drought in the region would be the safest bet.

"We would be better off preparing for a dry outcome and being pleasantly surprised if the rains perform well, rather than counting on good rains only to experience a fourth consecutive drought," he said.

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