What is EDDI?
The Evaporative Demand Drought Index (EDDI) is an experimental drought monitoring and early warning guidance tool. It examines how anomalous the atmospheric evaporative demand (E0; also known as "the thirst of the atmosphere") is for a given location and across a time period of interest. EDDI is multi-scalar, meaning that this period—or "timescale"—can vary to capture drying dynamics that themselves operate at different timescales; we generate EDDI at 1-week through 12-month timescales.
This webpage offers a frequently updated assessment of current conditions across CONUS, southern parts of Canada, and northern parts of Mexico; a tool to generate historical time series of EDDI for a user-selected region; introductions to the EDDI team; and a list of resources for users to explore EDDI and its applications further.
Why use EDDI?
EDDI can offer early warning of agricultural drought, hydrologic drought, and fire-weather risk by providing near-real-time information on the emergence or persistence of anomalous evaporative demand in a region. A particular strength of EDDI is in capturing the precursor signals of water stress at weekly to monthly timescales, which makes EDDI a strong tool for preparedness for both flash droughts and ongoing droughts.
How often is EDDI updated?
Currently, EDDI is generated daily—though with a 5-day lag-time—by analyzing a near-real-time atmospheric dataset. This lag-time results from the procedures to quality control the meteorological data used to estimate evaporative demand. There is also an ongoing effort to forecast EDDI based on seasonal climate-forecast information.
This work is supported in part by grants from (i) NOAA's Joint Technology Transfer Initiative (JTTI) for the project titled "Operationalizing an Evaporative Demand Drought Index (EDDI) service for drought monitoring and early warning;" (ii) NOAA's Sectoral Applications Research Program (SARP): Coping with Drought in Support of the National Integrated Drought Information System (NIDIS) program for the project titled "Developing a wildfire component for the NIDIS California Drought Early Warning System;" (iii) DOI's North Central Climate Science Center for the project (Grant #G14AP00182) titled "Ecological Drought, Climate Extremes and the Water Cycle across Timescales;" and (iv) Western Water Assessment, an NOAA RISA program, for the project titled "Enhancing the usability of EDDI," with funding originating from NIDIS.
Any issues with accessing the plots and other information on this page are welcome and should be sent to firstname.lastname@example.org.
For the month ending on September 12 (1-month EDDI), conditions across CONUS appear much less polarized than at the weekly timescale. The driest conditions remain in the west, with central CA again exhibiting ED4 (>98%ile), but abnormal dryness extending up the West Coast through OR (a small ED4 patch in southwestern OR), to WA, and across southern ID, southern and western WY, southern UT, western CO (again ED4 in the southwestern mountains) and parts of AZ. The southeastern CONUS and Appalachia and the Ohio Valley also saw drier-than-normal conditions in parts, though not exceeding ED1 (80-90%ile). Wetter-than-normal conditions (peaking at EW3, or 2-5%ile) prevailed across the Central Great Plains of KS, NE, and IA, and across southern and central MT and northern WY.
The seasonal timeframe (3-month EDDI) ending on September 12 shows strong lingering drought in the West Coast states, peaking at ED4 (>98%ile) across central CA, and ED3 (95-98%ile) up the Cascade Range across OR into southern WA. The Four Corners drought appears to have moved north into CO and eastern UT, where it peaks at ED3 (95-98%ile) in western CO. TX appears drier than normal, though only at ED0 (70-80%ile), as does the eastern Ohio Valley, and peninsular FL. The persistent dryness in MO shows up at this timescale at the ED0-ED2 intensity (70-95%ile). Northern New England and NY are also significantly drier than normal, with conditions reaching ED4 in upstate NY, and ED2 (90-95%ile) across VT, NH, and ME. Wetter-than-normal conditions occur in patches around CONUS: around southern NV at EW0-EW1 (10-30%ile); southern MT and northern WY (peaking at EW4, or <2%ile); in the north-central Great Plains (peaking at EW3, or 2-5%ile); in western KS (EW0-EW1, or 10-30%ile); and a small region of northern VA, western MD, and south-central PA (EW0, or 20-30%ile).
EDDI Project Team
Joe Barsugli • email@example.com • 303-497-6042Joe is a Research Scientist at CIRES and NOAA’s Physical Sciences Division. Trained in climate theory and modeling, he works at the technical interface connecting climate science with the practitioners and technical staff who are informing planning for water and land management in the Colorado region, and connecting researchers to the problems faced by managers.
Candida Dewes • firstname.lastname@example.org • 303-497-4236Candida is a Research Scientist at NOAA’s Physical Sciences Division and CIRES/Western Water Assessment at the University of Colorado, Boulder. She has extensive research experience in climate variability and climate change and their impacts on socio-ecological systems. Her current research focuses on regional-scale land surface processes contributing to drought, and in particular, the variability of evaporative demand under climate change. She is also interested in the role of rain versus snow in mountainous terrain how these precipitation types impact regional water resources.
Mike Hobbins • email@example.com • 303-497-3092Since obtaining his Ph.D. in Hydrologic Science and Engineering from Colorado State University in 2004, Mike has worked in research into evapotranspiration, evaporative demand, and drought. As a Research Scientist for NOAA’s Physical Sciences Division and the Cooperative Institute for Research in Environmental Sciences (CIRES) at the University of Colorado in Boulder, CO, his recent work supports drought early warning across the US for the National Integrated Drought Information Systems (NIDIS) and famine early warning across the globe for the Famine Early Warning Systems Network (FEWS NET), including the development and dissemination of reanalyses of evaporative demand; the development of the Forecast Reference Evapotranspiration (FRET) product for daily and weekly evaporative demand forecasts across the US; and the development of the EDDI.
Justin Huntington • firstname.lastname@example.org • 775-673-7670Justin Huntington is an associate research professor of Hydrology at the Desert Research Institute, Reno, Nevada. His research interests are focused on remote sensing, land surface energy balance measurement and modeling, drought monitoring, and hydrologic modeling. His research primarily supports water use, water demand, and drought mapping and prediction efforts funded by the U.S. Bureau of Reclamation, U.S. Geological Survey, U.S. Bureau of Land Management, NASA, NOAA, and Google. He is one of 25 members of the 2012-2017 Landsat Science Team.
Jeff Lukas • email@example.com • 303-735-2698Jeff is a Research Integration Specialist with the Western Water Assessment program at CIRES, based out of the University of Colorado Boulder. For the past 15 years, Jeff has worked closely with water managers and other resource decision-makers in the Rocky Mountain West to help them understand and prepare for climate-related vulnerabilities by interpreting and applying paleoclimate data, historical climate records, and climate projections. He was lead author of the 2014 Climate Change in Colorado report for the Colorado Water Conservation Board, which summarized the latest science on climate trends and projections for the state. Jeff was initially trained in forest ecology (M.S., Forestry, University of Montana) and conducted fire history research, later shifting into applied climatology and hydrology.
Daniel McEvoy • firstname.lastname@example.org • 775-673-7682Daniel is a researcher with the Western Regional Climate Center. His research interests are interdisciplinary and span the fields of climate, hydrology, and meteorology. They include advancing drought monitoring technology, seasonal drought prediction, the role of evaporative demand on drought, quality and uncertainty assessment of weather observations, and climate modeling.
Charles Morton • email@example.com • 775-673-7620Charles Morton is an assistant research scientist at the Desert Research Institute in Reno, NV. His research interests include surface energy balance modeling, hydrology, remote sensing, and cloud computing. For the past 10 years he has worked on numerous projects estimating evapotranspiration in the western United States using satellite remote sensing.
Imtiaz Rangwala • firstname.lastname@example.org • 303-497-6544Imtiaz is a research scientist at CIRES at the University of Colorado Boulder and NOAA’s Physical Sciences Division. He is a climate scientist with training in assessing and diagnosing regional scale climate change. Using climate observations and models, he works to understand and quantify climate processes relevant to regional warming trends and hydrological processes changes. This specifically ties into understanding climate extremes and changes in water balance in the western U.S., including the Great Plains region, and the how these extremes affect ecosystem response. Other work includes developing approaches to addressing and incorporating future climate change uncertainty into decision making and climate adaptation.
Andrea Ray • email@example.com • 303-497-6434Andrea is a research scientist at NOAA's Physical Sciences Division in Boulder, CO. Trained in environment and society geography, she studies user needs for climate forecasts, projections, and knowledge in natural resource management, decision making and adaptation. She often serves as a technical expert on planning and policy teams, working to transition research results into applications. Currently, she is serving on the interagency Climate Projections Team for the USGCRP Climate Resilience Toolkit, and on the Steering Team to develop a NOAA Water Resources Monitor and Outlook to provide enhanced outlooks on the runoff season. She recently led a climate analysis for the U.S. Fish and Wildlife Service to inform their Wolverine Species Status Assessment: Future snow persistence in Rocky Mountain and Glacier National Parks.
Heather Yocum • firstname.lastname@example.org • 303-497-3917Heather is a Research Scientist at the University of Colorado and NOAA’s Cooperative Institute for Research in Environmental Sciences (CIRES) in Boulder, CO. An environmental anthropologist and political ecologist, Dr. Yocum studies how culture and social systems impact the way that humans understand and interact with the environment. Since earning her PhD in Anthropology from Michigan State University in 2013, she has researched the production and use of climate and weather information to support natural resource management and decision-making; changing patterns of land use and natural resource management in the face of climate change; and environmental markets and payments for ecosystem services.
Primary Background Material
- A slow disaster scorched Wyo. No one saw it come or go
- A Wyoming Reservation Shows the New Face of Drought
- EDDI Webinar on 14 Mar 2018 — Slides (pdf)
- EDDI Webinar on 14 Mar 2018 — Recording (mp4)
- EDDI, a New Drought Index, Provides Early Warning of Flash Droughts
- A new NOAA tool is helping to predict US droughts, global famine
- New NOAA tool is helping to predict U.S. droughts, global famine
- EDDI: A powerfiul tool for early drought warning
- WWA: Intermountain West Climate Dashboard
- PSD News: New tool effectively identifies both rapid-onset and sustained droughts
- CONUS maps of monthly US climate division PDSI
- Time series of monthly US climate division PDSI and other variables
- M. Hobbins, A. Wood, D. McEvoy, J. Huntington, C. Morton, M. Anderson, and C. Hain (June 2016): The Evaporative Demand Drought Index: Part I – Linking Drought Evolution to Variations in Evaporative Demand. J. Hydrometeor., 17(6),1745-1761, doi:10.1175/JHM-D-15-0121.1.
- D. J. McEvoy, J. L. Huntington, M. T. Hobbins, A. Wood, C. Morton, M. Anderson, and C. Hain (June 2016): The Evaporative Demand Drought Index: Part II – CONUS-wide Assessment Against Common Drought Indicators. J. Hydrometeor., 17(6), 1763-1779, doi:10.1175/JHM-D-15-0122.1.
- Dewes, C. F., I. Rangwala, J. J. Barsugli, M. T. Hobbins, and S. Kumar (March 2017): Drought risk assessment under climate change is sensitive to methodological choices for the estimation of evaporative demand. PLoS ONE, 12(3), e0174045, doi:10.1371/journal.pone.0174045
- McNeeley, S. M., C. F. Dewes, C. J. Stiles, T. A. Beeton, I. Rangwala, M. T. Hobbins, and C. L. Knutson CL (2017): Anatomy of an interrupted irrigation season: Micro-drought at the Wind River Indian Reservation. Clim. Risk Mgt., doi:10.1016/j.crm.2017.09.004.
- Rondeau, R. J., K. L. Decker, and G. A. Doyle (January 2018): Potential consequences of repeated severe drought for shortgrass steppe species. Rangeland Ecol. Mgt., 71(1), 91–97, doi:10.1016/j.rama.2017.07.002.
- Shrum, T., W. Travis, T. Williams, and E. Lih (Online February 2018): Managing Climate Risks on the Ranch with Limited Drought Information. Clim. Risk Mgt., doi:10.1016/j.crm.2018.01.002.