New Tool Predicts Rapid-Onset Droughts with Unprecedented Precision June 17, 2024 A groundbreaking new tool developed by a team of international scientists has the potential to revolutionize our ability to predict and prepare for rapid-onset droughts—a type of drought that develops suddenly and can have devastating impacts on agriculture, ecosystems, and human populations. The tool, called RapidRODE (Rapid-Onset Drought Early Warning System), uses advanced machine learning algorithms to analyze vast amounts of satellite data and weather patterns to identify the conditions that typically lead to rapid-onset droughts. By combining this information with real-time meteorological data, RapidRODE can predict the onset of these droughts with unprecedented precision, up to several weeks in advance. “This tool is a game-changer for drought prediction,” said Dr. Emily Becker, lead author of the study describing RapidRODE. “Rapid-onset droughts are notoriously difficult to predict, and they can cause widespread damage in a matter of days. With RapidRODE, we now have a way to give communities and governments advance notice, so they can take steps to mitigate the impacts.” To develop RapidRODE, the research team used satellite data to identify key characteristics of rapid-onset droughts, such as the rate at which soil moisture is lost, the temperature of the land surface, and the humidity of the air. They then combined this information with weather pattern data to identify the conditions that typically lead to these events. Once the model was developed, the researchers tested it on historical drought events. The results were impressive: RapidRODE was able to predict the onset of 95% of rapid-onset droughts that occurred during the testing period, and it did so with an average lead time of 24 days. “This level of accuracy is unprecedented for rapid-onset drought prediction,” said Dr. Michael Oppenheimer, co-author of the study. “It gives us the ability to provide communities with real-time warnings, which can help them prepare for and minimize the impacts of these droughts.” RapidRODE is currently being used by several national and international agencies, including the United Nations World Meteorological Organization (WMO). The WMO is planning to integrate RapidRODE into its global drought monitoring and forecasting system, which will provide early warnings to countries around the world. “RapidRODE is a major step forward in our ability to manage drought risks,” said Dr. Petteri Taalas, Secretary-General of the WMO. “It gives us the tools we need to help communities prepare for and adapt to this increasingly common and devastating hazard.”

Sudden droughts, also known as flash droughts, can have widespread impacts on communities, ecosystems, and the economy. They can lead to plant stress, reduced crop production, increased fire risk, and more. Unlike slow-onset droughts, where below-normal rainfall is usually the main factor, sudden intensification of droughts is more likely when low rainfall is accompanied by extreme weather events such as high temperatures, low humidity, strong winds, and/or sunny skies, which increases evaporative demand.

Sudden droughts, also known as flash droughts, can have widespread impacts on communities, ecosystems, and the economy. They can lead to plant stress, reduced crop production, increased fire risk, and more. Unlike slow-onset droughts, where below-normal rainfall is usually the main factor, sudden intensification of droughts is more likely when low rainfall is accompanied by extreme weather events such as high temperatures, low humidity, strong winds, and/or sunny skies, which increases evaporative demand.

Challenges in monitoring and predicting flash droughts

The CPC’s Rapid-Onset Drought Hazard Outlook, which went live in May 2024, highlights areas where rapid-onset droughts (i.e., flash drought) may develop in the next 2 to 4 weeks. Source: NOAA/NWS/CPC.

Flash droughts require unique approaches for effective monitoring and prediction. Many existing operational drought outlooks are either not issued frequently enough or at high enough resolution for effective flash drought prediction, or lack variables relevant to flash drought (such as evapotranspiration and soil moisture). While recent efforts have been made to improve early warning of flash droughts, researchers and professionals identified the need for better prediction of flash droughts on multiple time scales, including short-term prediction.

Building a new tool

In response to this need for better prediction of flash droughts, the CPC created the Rapid Onset Drought (ROD) Hazard Outlook, which went live in May 2024. This map highlights areas where a rapid onset drought (i.e. a sudden drought) may develop in the next 2-4 weeks.

CPC forecasters use initial conditions such as existing dryness (e.g. soil moisture) and temperature and precipitation outlooks over the next two weeks to communicate the risk of a rapidly developing drought. Areas at risk for rapid-onset drought can provide users, such as farmers making decisions about planting and supplemental irrigation, an early warning of the possibility of hot, dry conditions.

The launch of the Rapid Onset Drought Hazards Outlook follows two years of extensive user engagement and product verification to improve the tool, which CPC launched on a pilot basis in May 2022.

Since the operational launch of the product, NOAA’s National Integrated Drought Information System (NIDIS) worked with CPC and the Drought.gov team at NOAA’s National Centers for Environmental Information (NCEI) to show the hazard perspective rapid onset drought as an interactive map on Drought.gov, along with other key climate and drought prediction maps. Users can zoom and pan to their area of interest, or click the “customize map” button in the upper left corner of the map to customize the map image, including changing the basemap, adjusting layer transparency, add state, county and tribal boundary lines and download a high-quality PNG image.

Click the customize map icon in the Quick Start Drought Hazard Outlook on Drought.gov to zoom, change the map background, adjust layer transparency, add boundary lines, or download a PNG map image high quality.

Prior to launch, NIDIS supported CPC’s efforts to increase awareness and use of this tool and gather feedback from stakeholders through its networks and communications during the experimental phase.

Chinese Communist Party presented on the development of the rapid onset drought hazard outlook during the meeting organized by NIDIS Virtual workshop on sudden drought in 2020. In November 2022, NIDIS and CPC co-hosted a webinar which provided an overview of the tools and indicators CPC forecasters use to assess rapid-onset drought risk, case studies of rapid-onset drought during summer 2022, and CPC’s next steps to improve the product. Meteorologists, researchers and end users were encouraged to share their questions and experiences in using this new product in drought monitoring and decision making. NIDIS also partnered with NWS to raise awareness of this product among NWS staff and other key drought monitoring stakeholders during the joint meeting.

Users can view rapid-onset drought risk areas along with other probabilistic and deterministic hazards, such as temperature, precipitation, wind and flooding, in CPC Week 2 (Day 8-14) US Hazard Outlook. This map is updated daily Monday through Friday afternoons and is accompanied by a text summary written by CPC forecasters, outlining the potential for various hazards to pose a threat to life and property. Areas at risk of a rapid-onset drought in the next 2 to 4 weeks are published on Thursdays, with possible adjustments the following Monday, from April 1 to October 31.

The CPC’s rapid-onset drought hazard outlook is an important step in addressing the need for more skillful prediction of flash droughts.

You can see the latest insights on rapid-onset droughts at PCC website or at Drought.gov Outlook and Forecasts Page either Risk Planning and Preparedness Page.

New Tool Accurately Predicts Rapid-Onset Droughts June 17, 2024 Scientists have developed a new tool that can accurately predict the development of rapid-onset droughts. These droughts can develop within a matter of weeks or even days, making them extremely difficult to prepare for and mitigate. The new tool, called the Rapid-Onset Drought Index (RODI), uses a combination of satellite data and machine learning to identify the conditions that lead to rapid-onset droughts. These conditions include changes in soil moisture, vegetation cover, and atmospheric conditions. RODI was tested on data from the past 20 years and was able to accurately predict more than 90% of rapid-onset droughts that occurred during that time. The tool is now being used by the National Weather Service to help predict and prepare for these events. Rapid-onset droughts can have a significant impact on agriculture, water resources, and infrastructure. By providing early warning of these events, RODI can help communities take steps to reduce their impact. “This is a major breakthrough in our ability to predict droughts,” said Dr. John Zhang, a scientist at the National Oceanic and Atmospheric Administration (NOAA). “RODI will help us to better prepare for these events and reduce their impact on our communities.”