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2023 Western Drought Webinar: May 9, 2023

Event Date
May 9, 2023
Event Time
12:00 pm - 1:30 pm

NOAA’s National Integrated Drought Information System (NIDIS), in partnership with NOAA’s National Centers for Environmental Information (NCEI) and National Weather Service’s Climate Prediction Center, hosted the 2023 Western Drought Webinar on May 9 to provide the latest information on current drought conditions and outlooks. Speakers from the U.S. Geological Survey, National Weather Service's Colorado Basin River Forecast Center, and NOAA’s Physical Sciences Laboratory (PSL) also provided updates on groundwater conditions, the Colorado River Basin, and how the wet winter will or will not impact long-term drought in the West.

On December 20, 2022, 64.6% of the West was in drought, according to the U.S. Drought Monitor. Over the 3-week period starting on December 26, a series of 9 atmospheric rivers (ARs) brought significant amounts of rain and snow to California, the Great Basin, and parts of Colorado River Basin. Strong storms continued throughout the winter, leaving record snowpack in large parts of the West. Many reservoirs, especially in California, filled fairly quickly to levels not seen in years. As a result, flooding eclipsed drought as an immediate concern in many areas, and continues to be a concern as the snow melts. The percentage of the West in drought plummeted to 27.1% by April 11, 2023. The winter deluge occurred in the context of large parts of West having been ensnared in continuous drought since 2020 as well as a climate-driven megadrought since the early 2000s. 

While the extreme precipitation improved and removed drought (according to the U.S. Drought Monitor) in many parts of the West, issues remain in parts of the Pacific Northwest and Colorado. The AR events over the winter months didn’t reach every drought-burdened Western state, with some receiving below-normal precipitation over the winter. Additionally, it will take more than one wet winter, even with record-breaking precipitation, to replenish groundwater in many areas as well as Lakes Powell and Mead, which are still near record low levels.


Welcome to the 2023 Western U.S. Drought Webinar & Introduction to NIDIS

Speaker: Veva Deheza | NOAA's National Integrated Drought Information System (NIDIS)

  • The National Integrated Drought Information System (NIDIS) was established by Congress in 2006.
  • Mission: 
    • Develop and provide a national drought early warning system. 
    • Coordinate and integrate as practicable, Federal research in support of a drought early warning system.
    • Build upon existing forecasting and assessment programs and partnerships.
  • Learn more at



Drought Conditions

Speaker: Joseph Casola | NOAA's National Centers for Environmental Information

  • There has been substantial improvement in drought conditions across most of the West.
  • Drought improvements were a consequence of above-average precipitation, colder-than-average temperatures, and abundant snowpack.
  • Smaller areas of drought remain in parts of the Pacific Northwest, southern Nevada, and eastern New Mexico.
  • Reservoir levels in the Colorado River Basin continue to reflect multi-year deficits in precipitation.



Drought Outlook

Speaker: David Dewitt | NOAA National Weather Service's Climate Prediction Center

  • The heavy western snowfall this past winter has ameliorated drought conditions across much of the western U.S.
  • Drought development is predicted for eastern Washington, western Texas, eastern Kansas, and north-central New Mexico. 
  • Predictions for the upcoming fall and winter will be strongly influenced by the expected onset of El Niño conditions. El Niño conditions in winter favor an enhanced probability for above-normal precipitation for the southern third of the U.S., and below-normal precipitation for the northern third of the U.S.
  • Predictions with more specificity as to the strength of the El Niño, its expected impacts, and other relevant climate modes will be made closer to the winter season.



Groundwater Update

Speaker: Jon Traum | U.S. Geological Survey

  • The interconnection of groundwater and surface water, on both the demand and supply side, is an important aspect of water management in the West. Groundwater systems recharge is limited by several factors, and groundwater levels do not recover as quickly as surface supplies.
  • Change in groundwater levels and change in storage from recent wet periods:
    • Groundwater level measurements are useful data but only represent one point in the aquifer. Numerical model simulations are used to estimate the change in groundwater storage as well as the entire groundwater budget.
    • View provisional groundwater data via USGS.
  • Even if we recover groundwater levels, land subsidence is a permanent effect of groundwater pumping and drought.
    • Irreversible land compaction results from groundwater pumping and causes damage to infrastructure and the environment. 
    • Subsidence is often delayed, resulting in continued subsidence even during wet periods.
  • How to achieve increased groundwater recharge?
    • Managed Aquifer Recharge (MAR) and conjunctive use of surface water and groundwater has been practiced for decades in the West. 
    • Increased surface water use in lieu of groundwater pumping
    • Increased local storage
    • Artificial recharge by surface infiltration
    • Protection of natural recharge areas
    • Aquifer storage and recovery systems
    • Reservoir reoperation
    • Overcoming water rights issues.



Colorado River Basin Update

Speaker: Paul Miller | NOAA National Weather Service's Colorado Basin River Forecast Center

  • Multiple Atmospheric River events brought frequent precipitation events to the Colorado River Basin, especially Utah, central Arizona, and western Colorado.
  • Water year to date precipitation was >150% of average across the majority of the Colorado River Basin. NRCS SNOTEL stations recorded similar values.
  • Colder-than-normal temperatures across the region led to additional snow accumulation across lower elevations, with minimal snowmelt occurring.
  • Forecasts throughout the Colorado River Basin and Great Basin are well above average, with some exceptions, such as the westernmost portions of the Gunnison and Colorado River headwaters. Forecast seasonal (April–July) unregulated inflow is 11.0 million acre-feet, or 172% of average, into Lake Powell.
  • The Southern Sierra is still showing record snowpack for this time of year. This includes the Tulare Lake area; other parts of the Sierra are falling below record conditions. Forecasted seasonal runoff for much of the Southern Sierra are at record levels.
  • Colorado Basin River Forecast Center website
  • NWS western water supply forecasts



Long-Term Drought in the West

Speaker: Andrew Hoell | NOAA Physical Sciences Laboratory

  • 2000-2022 in the Western United States: Compound low precipitation and high temperatures prevailed.
  • Temperature and precipitation relationship varies spatially. Higher temperatures recently led to more compound annual extremes.
  • Copious precipitation in the 2022–2023 wet season mildly alleviated precipitation deficits from the prior 23 years.
  • The 2022–2023 wet season has made Water Year 2023 one of the wettest water years since 2000.
  • 2000-2023 wet interludes in the midst of drought occurred in the presence of anomalously high temperatures.
  • 1980–1999 dry interludes in the midst of wetness occurred in the presence of lower temperatures compared to post-2000.
  • The El Niño–Southern Oscillation (ENSO) is not always a reliable predictor of Basin precipitation. However, the highest precipitation years in California and the Upper Colorado Basin are related to strong El Niño events.



Question & Answers




Speaker: Veva Deheza | NOAA's National Integrated Drought Information System (NIDIS)