Winter Kicks Off With a Mix of Snowpack Conditions in the West
Key Points
- Substantial snow water equivalent (SWE) deficits emerged across areas in the Rocky Mountains, where above-average temperatures and drought persisted into the new water year.
- Snow drought is most prevalent across Wyoming, Arizona, New Mexico, and southwest Montana. Low precipitation is driving snow drought across these states.
- An active weather pattern across the Cascade Range and Sierra Nevada in November buffered snowpack conditions despite a recent multi-week dry spell.
- Temperature will play a key role in snow drought development. Current National Weather Service outlooks favor above-normal temperatures for all of the western states through December.
- Early season snow drought conditions can change rapidly, especially at lower elevations, with increased variability in weather patterns during late fall and early winter. Early in the season, snow drought recovery can be rapid. Recovery from snow drought in late winter and early spring, when snowpack is typically near peak, can be slower.
Snow Telemetry (SNOTEL) snow water equivalent (SWE) values for watersheds in the western U.S. as a percentage of the 1991–2020 median recorded by the USDA Natural Resources Conservation Service (NRCS). Only stations with at least 20 years of data are included in the station averages.
The SWE percent of median, in this figure and in the text, represents the current SWE at selected SNOTEL stations in or near the basin compared to the median value for those stations on the same date from 1991–2020. This map is valid through the end of the day December 8, 2024.
For an interactive version of this map, please visit NRCS.
Snow Telemetry (SNOTEL) and snow course snow water equivalent (SWE) values for watersheds in Alaska as a percentage of the 1991–2020 median recorded by the USDA Natural Resources Conservation Service (NRCS). Only stations with at least 20 years of data are included in the station averages.
The SWE percentage of median, in this figure and in the text, represents the current SWE at selected SNOTEL stations in or near the basin compared to the median value for those stations on the same date. This map is valid through the end of the day December 8, 2024.
For an interactive version of this map, please visit NRCS.
Drought is defined as the lack of precipitation over an extended period of time, usually for a season or more, that results in a water shortage. Changes in precipitation can substantially disrupt crops and livestock, influence the frequency and intensity of severe weather events, and affect the quality and quantity of water available for municipal and industrial use.
Learn MoreSnow drought is a period of abnormally low snowpack for the time of year. Snowpack typically acts as a natural reservoir, providing water throughout the drier summer months. Lack of snowpack storage, or a shift in timing of snowmelt, can be a challenge for drought planning.
Learn MorePeriods of drought can lead to inadequate water supply, threatening the health, safety, and welfare of communities. Streamflow, groundwater, reservoir, and snowpack data are key to monitoring and forecasting water supply.
Learn MoreIn a drought, lower water levels or snowpack can affect the availability of recreational activities and associated tourism, and a resulting loss of revenue can severely impact supply chains and the economy. Drought—as well as negative perceptions of drought, fire bans, or wildfires—may also result in decreased visitations, cancellations in hotel stays, a reduction in booked holidays, or reduced merchandise sales.
Learn MoreDrought is defined as the lack of precipitation over an extended period of time, usually for a season or more, that results in a water shortage. Changes in precipitation can substantially disrupt crops and livestock, influence the frequency and intensity of severe weather events, and affect the quality and quantity of water available for municipal and industrial use.
Learn MoreSnow drought is a period of abnormally low snowpack for the time of year. Snowpack typically acts as a natural reservoir, providing water throughout the drier summer months. Lack of snowpack storage, or a shift in timing of snowmelt, can be a challenge for drought planning.
Learn MorePeriods of drought can lead to inadequate water supply, threatening the health, safety, and welfare of communities. Streamflow, groundwater, reservoir, and snowpack data are key to monitoring and forecasting water supply.
Learn MoreIn a drought, lower water levels or snowpack can affect the availability of recreational activities and associated tourism, and a resulting loss of revenue can severely impact supply chains and the economy. Drought—as well as negative perceptions of drought, fire bans, or wildfires—may also result in decreased visitations, cancellations in hotel stays, a reduction in booked holidays, or reduced merchandise sales.
Learn MorePercent of Median Snow Water Equivalent
< 50% of Median
Current snow water equivalent (SWE) is less than 50% of the median SWE value for this day of the year, compared to historical conditions from 1991–2020.
50%–70% of Median
Current snow water equivalent (SWE) is between 50%–70% of the median SWE value for this day of the year, compared to historical conditions from 1991–2020.
70%–90% of Median
Current snow water equivalent (SWE) is between 70%–90% of the median SWE value for this day of the year, compared to historical conditions from 1991–2020.
90%–110% of Median
Current snow water equivalent (SWE) is between 90%–110% of the median SWE value for this day of the year, compared to historical conditions from 1991–2020.
110%–130% of Median
Current snow water equivalent (SWE) is between 110%–130% of the median SWE value for this day of the year, compared to historical conditions from 1991–2020.
130%–150% of Median
Current snow water equivalent (SWE) is between 130%–150% of the median SWE value for this day of the year, compared to historical conditions from 1991–2020.
>150% of Median
Current snow water equivalent (SWE) is greater than 150% of the median SWE value for this day of the year, compared to historical conditions from 1991–2020.
Percent of Median Snow Water Equivalent
< 50% of Median
Current snow water equivalent (SWE) is less than 50% of the median SWE value for this day of the year, compared to historical conditions from 1991–2020.
50%–70% of Median
Current snow water equivalent (SWE) is between 50%–70% of the median SWE value for this day of the year, compared to historical conditions from 1991–2020.
70%–90% of Median
Current snow water equivalent (SWE) is between 70%–90% of the median SWE value for this day of the year, compared to historical conditions from 1991–2020.
90%–110% of Median
Current snow water equivalent (SWE) is between 90%–110% of the median SWE value for this day of the year, compared to historical conditions from 1991–2020.
110%–130% of Median
Current snow water equivalent (SWE) is between 110%–130% of the median SWE value for this day of the year, compared to historical conditions from 1991–2020.
130%–150% of Median
Current snow water equivalent (SWE) is between 130%–150% of the median SWE value for this day of the year, compared to historical conditions from 1991–2020.
>150% of Median
Current snow water equivalent (SWE) is greater than 150% of the median SWE value for this day of the year, compared to historical conditions from 1991–2020.
Snow Telemetry (SNOTEL) snow water equivalent (SWE) values for watersheds in the western U.S. as a percentage of the 1991–2020 median recorded by the USDA Natural Resources Conservation Service (NRCS). Only stations with at least 20 years of data are included in the station averages.
The SWE percent of median, in this figure and in the text, represents the current SWE at selected SNOTEL stations in or near the basin compared to the median value for those stations on the same date from 1991–2020. This map is valid through the end of the day December 8, 2024.
For an interactive version of this map, please visit NRCS.
Snow Telemetry (SNOTEL) and snow course snow water equivalent (SWE) values for watersheds in Alaska as a percentage of the 1991–2020 median recorded by the USDA Natural Resources Conservation Service (NRCS). Only stations with at least 20 years of data are included in the station averages.
The SWE percentage of median, in this figure and in the text, represents the current SWE at selected SNOTEL stations in or near the basin compared to the median value for those stations on the same date. This map is valid through the end of the day December 8, 2024.
For an interactive version of this map, please visit NRCS.
View an updated, interactive version of this map from the USDA's Natural Resources Conservation Service. You can also view SWE data on Drought.gov.
View an updated, interactive version of this map from the USDA's Natural Resources Conservation Service. You can also view SWE data on Drought.gov.
Drought is defined as the lack of precipitation over an extended period of time, usually for a season or more, that results in a water shortage. Changes in precipitation can substantially disrupt crops and livestock, influence the frequency and intensity of severe weather events, and affect the quality and quantity of water available for municipal and industrial use.
Learn MoreSnow drought is a period of abnormally low snowpack for the time of year. Snowpack typically acts as a natural reservoir, providing water throughout the drier summer months. Lack of snowpack storage, or a shift in timing of snowmelt, can be a challenge for drought planning.
Learn MorePeriods of drought can lead to inadequate water supply, threatening the health, safety, and welfare of communities. Streamflow, groundwater, reservoir, and snowpack data are key to monitoring and forecasting water supply.
Learn MoreIn a drought, lower water levels or snowpack can affect the availability of recreational activities and associated tourism, and a resulting loss of revenue can severely impact supply chains and the economy. Drought—as well as negative perceptions of drought, fire bans, or wildfires—may also result in decreased visitations, cancellations in hotel stays, a reduction in booked holidays, or reduced merchandise sales.
Learn MoreDrought is defined as the lack of precipitation over an extended period of time, usually for a season or more, that results in a water shortage. Changes in precipitation can substantially disrupt crops and livestock, influence the frequency and intensity of severe weather events, and affect the quality and quantity of water available for municipal and industrial use.
Learn MoreSnow drought is a period of abnormally low snowpack for the time of year. Snowpack typically acts as a natural reservoir, providing water throughout the drier summer months. Lack of snowpack storage, or a shift in timing of snowmelt, can be a challenge for drought planning.
Learn MorePeriods of drought can lead to inadequate water supply, threatening the health, safety, and welfare of communities. Streamflow, groundwater, reservoir, and snowpack data are key to monitoring and forecasting water supply.
Learn MoreIn a drought, lower water levels or snowpack can affect the availability of recreational activities and associated tourism, and a resulting loss of revenue can severely impact supply chains and the economy. Drought—as well as negative perceptions of drought, fire bans, or wildfires—may also result in decreased visitations, cancellations in hotel stays, a reduction in booked holidays, or reduced merchandise sales.
Learn MoreSnow Drought Conditions Summary
This update is based on data available as of Monday, December 9, 2024 at 12:00 a.m. PT. We acknowledge that conditions are evolving.
Early season snow drought conditions are widespread throughout northern Utah, Wyoming, and southwestern Montana due to a warm, dry start to the water year (starting October 1). Drought has persisted in the region for the past year, partially due to low snowpack from the previous water year. The mountains in Northern Arizona have also started the season with below-normal snowpack. Elsewhere across the West, early season snowpack generally started near to above normal, but dryness over the past two weeks quickly brought many locations closer to normal or below normal, particularly in the northern Cascade Range.
Jump to conditions for your region:
- Rocky Mountain Snow Conditions (Colorado, Idaho, Montana, Utah, Wyoming)
- New Mexico and Arizona Snow Conditions
- Oregon and Washington Snow Conditions
- California and Nevada Snow Conditions
- Alaska Snow Conditions
Stations with SWE Below the 30th Percentile in the Western U.S.
Key Takeaway: Snow drought conditions developed across the northern Rocky Mountains, where snow water equivalent (SWE) is below the 10th percentile at many SNOTEL stations. Some SNOTEL stations in southwestern Montana and in Wyoming are reporting record low SWE.
30-Day Precipitation as a Percentage of Normal Across Basins in the Western U.S.
Key Takeaway: A recent dry spell has left many basins in the Rocky Mountains with less than 70% of average precipitation. Precipitation totals and snow water equivalent (SWE) are substantially below average in Wyoming, Arizona, and New Mexico.
Rocky Mountain Snow Conditions (Colorado, Idaho, Montana, Utah, Wyoming)
The Rocky Mountains started the water year with an extremely warm and dry October. According to the U.S. Drought Monitor, drought in this region persisted from the last snow season. A poor start to this water year could lead to expanded drought conditions and potential cascading impacts, including wildfires, and low river and reservoir levels.
Northern Rockies
Snowpack accumulation is off to a slow start throughout northern Utah, Wyoming, and southwestern Montana. Many locations reported less than 60% of normal snow water equivalent (SWE) for this time of year, with nine Snow Telemetry (SNOTEL) stations in Wyoming and one station in Montana reporting record low SWE. November brought scattered weak storms and near-normal temperatures. Conditions in central and northern Idaho and northwest Montana report near to above normal SWE generally.
Central Rockies
In central Utah and most of Colorado, snowpack is near-to-above normal. Notable snow storms in late October and another significant storm in late November, established average to above-average early season SWE. However, the mountains in far southwestern Utah did not receive these early season storms, leading to below-normal SWE.
Water Year Accumulated Snow Water Equivalent in the Snake River Headwaters HUC 6 Basin
Key Takeaway: Persistent drought conditions and above average temperatures across the Snake River headwaters region led to nearly record low snow water equivalent (SWE) for this time of year. Early season snowpack is significantly below normal.
Arizona and New Mexico Snow Conditions
All SNOTEL stations in Arizona, with the exception of Snowslide Canyon north of Flagstaff, report below-normal snow water equivalent (SWE). Most stations have SWE below 25% of normal, largely driven by minimal precipitation to date. A few isolated locations received precipitation in October and early November, but most locations went without. These high elevation precipitation events fell as rain instead of snow
Large storms in northern New Mexico in mid-October and early November boosted the early season snowpack, but little precipitation occurred since early November. Snowpack conditions vary across the state, with mostly below normal SWE in the Upper Rio Grande basin (76%), Rio Grande-Elephant Butte basin (80%), and Upper Canadian basin (91%). The Taos SNOTEL station received over 20 inches of snow from October 1 through November 9. Since then it has been dry, reporting less than a half of an inch of precipitation.
Water Year Accumulated Snow Water Equivalent in the Salt River HUC 6 Basin
Key Takeaway: Above-average temperatures and below-normal precipitation have greatly reduced snow water equivalent (SWE) values in the Salt Basin.
Oregon and Washington Snow Conditions
An active weather pattern from the end of October through the third week of November brought significant snowfall throughout the Cascade Range in Oregon and Washington. Snow water equivalent (SWE) quickly climbed to above normal for most of the region. This increase exhibited a pronounced north-south gradient, with SWE surpassing 240% of median in the southern Oregon Cascades and gradually decreasing to near-normal levels toward the northern Washington Cascades.
A typical Pacific Northwest winter dry spell then set in for about two weeks, and some snow melted at lower elevations, leading to localized snow drought conditions in early December. Several locations in the central Washington Cascade Range, near the Stampede Pass area, are now reporting below normal SWE, with a few sites reporting less than 50% of normal. Similarly, a cluster of three lower elevation stations in the Central Oregon Cascade Range (Daly Lake at 3,690 feet; Jump Off Joe, 3,520 feet; and Marion Forks, 2,590 feet) lost SWE over the past two weeks, falling below 50% of normal. SWE levels in Oregon and Washington are currently above normal. Active weather, including more snowfall, is expected to return to the Cascade Range later this week.
California and Nevada Snow Conditions
After a dry start to the water year, late November storms brought the first significant snowfall to the Sierra Nevada. Mid-to-high elevation locations on the west slope of the northern Sierra Nevada received substantial snow in the third week of November and above normal snow water equivalent (SWE) has persisted since then. Areas to the east of the Sierra Nevada crest, such as the Carson Range, were in a strong rain shadow and received much less snow. A second storm during the last week of November favored the central and southern Sierra Nevada from about Mammoth to Bishop. Mammoth Pass gained seven inches of SWE from November 23 through November 27.
Despite recent dry conditions, SWE is above normal in most areas, but below normal at lower elevation stations. In the Great Basin, snowpack is generally above normal in central and northern Nevada. The Humboldt Basin is currently reporting 138% of normal SWE and Central Nevada Deserts Basins are reporting 144% of normal SWE.
Alaska Snow Conditions
In south-central Alaska, a storm cycle from the end of October through the first week of November initially led to above normal snowpack for the entire region. Conditions in November were drier than Normal, but changed abruptly December 1, when above-normal temperatures and rain were recorded at many stations, resulting in a loss of snowpack. Currently the Kenai Peninsula, Knik Arm, and Prince William Sound basins are at 99%, 82%, and 71% of normal snow water equivalent (SWE), respectively. The Susitna Basin, with two SNOTEL stations reporting, is currently at 55% of normal SWE. A substantial late October storm in interior Alaska around the Fairbanks area brought above normal snowfall to the region, and SWE has been above normal since then. A substantial late October storm brought near-record SWE increases to the higher elevations around Fairbanks, and has contributed heavily to the above normal SWE in the region. Mt. Ryan SNOTEL and several December 1 Snow Course measurements are reporting the highest SWE on record for the date.
* Quantifying snow drought values is an ongoing research effort. Here we have used the 30th percentile as a starting point based on partner expertise and research. Get more information on the current definition of snow drought.
For More Information, Please Contact:
Daniel McEvoy
Western Regional Climate Center
Daniel.McEvoy@dri.edu
Jason Gerlich
CIRES/NOAA/NIDIS Pacific Northwest and Missouri River Basin Regional Drought Information Coordinator
Jason.Gerlich@noaa.gov
Gretel Follingstad
CIRES/NOAA/NIDIS Intermountain West Regional Drought Information Coordinator
Gretel.Follingstad@noaa.gov
Amanda Sheffield
CIRES/NOAA/NIDIS California-Nevada Regional Drought Information Coordinator
Amanda.Sheffield@noaa.gov
NIDIS and its partners launched this snow drought effort in 2018 to provide data, maps, and tools for monitoring snow drought and its impacts as well as communicating the status of snow drought across the United States, including Alaska. Thank you to our partners for your continued support of this effort and review of these updates. If you would like to report snow drought impacts, please use the link below. Information collected will be shared with the states affected to help us better understand the short term, long term, and cumulative impacts of snow drought to the citizens and the economy of the regions reliant on snowpack.
Report Your Snow Drought Impacts
Data and Maps | Snow Drought
Research and Learn | Snow Drought
