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 email@example.com.
For the month ending on October 10 (1-month EDDI), conditions across CONUS show continued intense dryness (ED4, or >98%ile) persisting across a region that includes almost all of UT, parts of southwestern WY, the western half of CO, parts of southern NV and eastern CA. This region is surrounded by a larger region of ED3-ED2 (90-95%ile) that extends over about twice the area, including all of eastern CO, parts of northeastern NM, the southwestern quadrant of WY, and southeastern ID. In this region, conditions are improving over CA, NV, southern ID, WY, and western areas OR and WA. Meanwhile, conditions around the lower Colorado River (southern NV, southeastern CA, and southwestern AZ), a region of southeastern CO and northeastern NM are degrading. Another area of abnormal dryness generally at ED0 (70-80%ile) to ED1 (80-90%ile), stretches in patches from MO northeastward across the Ohio Valley into western NY. Conditions here are deteriorating relative to last week. Also dry and deteriorating is FL, where dryness peaks at ED3 in far-southern parts around Miami. Note again, that this period does not include the effects of the landfall of Hurricane Michael on October 10. Wetter than normal or neutral conditions prevail across much of the rest of CONUS—particularly in the Gulf Coast of TX, central MT, the southern Great Plains, IA and southern MN, and the mid-Atlantic Seaboard.
The seasonal timeframe (3-month EDDI) ending on October 10 shows strong lingering drought in two regions of the west: a region from central CA, where ED4 (>98%ile) conditions prevail, stretching northward at ED1 (80-90%ile) to ED2 (90-95%ile) up across CA, northwestern NV, southern ID, most of OR, and through western WA to Canada; meanwhile, the drought in CO, UT, and southwestern WY lingers at ED3-ED4 (>95%ile), and stretches at ED1-ED2 (80-95%ile) across western CO, eastern UT, southwestern WY, and southern ID. Strong and lingering drought remains over northern NY (ED3, or 95-98%ile), and across northern New England (peaking at ED2, or <95%ile) in eastern ME. Southern MO remains in drought at ED0-ED2 (70-95%ile). Other regions in drier-than-normal conditions include, the Red River of the North in eastern ND and northwestern MN (peaking at ED2, or 90-95%ile), and peninsular FL, where ED2 (90-95%ile) conditions now cover the peninsula, a deepening of drought over last week. Wetter-than-normal conditions continue to prevail across a region stretching from southern MT across northeastern WY, down the central Great Plains, and a small region of wetter-than-normal conditions around the DC area. The most significant changes since this time last week appear to be a lessening in intensity around the drought area of UT and CO, in NY and northern New England, and along the northern CA coast. While the dryness in peninsular FL appears to be increasing, this does not reflect any recent impacts from Hurricane Michael which made on October 10, after these latest data became available.
EDDI Project Team
Joe Barsugli • firstname.lastname@example.org • 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 • email@example.com • 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 • firstname.lastname@example.org • 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 • email@example.com • 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 • firstname.lastname@example.org • 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 • email@example.com • 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 • firstname.lastname@example.org • 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 • email@example.com • 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 • firstname.lastname@example.org • 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 • email@example.com • 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.