Event Date & Time
The Evaporative Demand Drought Index, or EDDI, is a drought index that can serve as an indicator of both rapidly evolving “flash” droughts (developing over a few weeks) and sustained droughts (developing over months but lasting up to years) and that has been shown to provide earlier warning of drought than many established drought indices, such as the US Drought Monitor. EDDI is currently under development at NOAA’s Physical Sciences Division and the Desert Research Institute and is slated for operationalization at the National Water Center by May, 2019. However, it is currently available on a quasi-operational basis from PSD for the whole of CONUS, and it may be tailored to your specific region on request.
EDDI examines how anomalous the atmospheric evaporative demand (E0; also known as "the thirst of the atmosphere") is for a given location at various timescales from 1 week through 12 months. By using a fully physical E0, EDDI captures drought dynamics from the demand perspective. This approach offers both early warning and a more-nuanced appreciation of the meteorological drivers of drought beyond the traditional reliance on precipitation and temperature. More information on EDDI, including current conditions and a user manual, is available in this 2-page handout and on the EDDI webpage.
During the webinar, we’ll briefly summarize the physical underpinnings of EDDI and its use as a drought monitor and early warning indicator, using examples from past droughts. We will focus on applications, including: using EDDI as a monitor of agricultural and hydrologic drought; using EDDI as a predictor of wildfire risk (showing early results from CA/NV); and how you can access both historical and up-to-date EDDI for your region.
We’ll also discuss new updates to the EDDI product, including: Webpage: a new EDDI webpage that includes current conditions, a nearly 40-year archive, a User Manual, and a tool to plot timeseries of EDDI for a specified region. Attribution: the ability to determine to what extent each of the drivers of E0 is driving its anomalous behavior, and so potentially driving drought. EDDI change maps: mapping the changes in EDDI-category across a given time period, designed to assist users in recognizing emerging drying (and wetting) events.
The intended audience for the webinar includes:
- Drought information providers including boundary organizations such as RISAs, USDA Climate Hubs, and USGS Climate Science Centers;
- NIDIS Drought Early Warning Systems teams;
- US Drought Monitor authors;
- Federal, state, regional, and tribal water managers;
- NOAA River Forecast Centers and Regional Climate Service Directors; State climatologists;
- and current users of EDDI.
The webinar will last 45 minutes, with 15 minutes for questions. The slides and audio will be recorded and made available afterwards on the EDDI website.
NIDIS, along with NOAA Earth Systems Research Laboratory, Western Water Assessment, CIRES, Colorado University, Desert Research Insititute and North Central Climate Center, has been supporting the development of EDDI.