Statewide conditions

As the state's lead agency for water supplies, we pay close attention to multiple data sources and monitor them closely. Here you can find:

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Current climate conditions & previous month's data
Expert knowledge, chaired by Dept. of Ecology
Predicted forecasts (based on accumluated data)
Data round-up of latest information from multiple agencies!

What is WSAC?

The Water Supply Availability Committee (WSAC) is a group of experts from state and federal agencies who evaluate statewide water supply conditions. Ecology chairs this group that provides an important consultative role to Ecology. WSAC advises Ecology on current and forecasted water supply conditions and whether the hydrologic drought threshold has been met or is likely to be met: seventy-five percent of normal water supply within a geographic area (RCW 43.83B.405 and WAC 173-166-050).

If you would like to receive notices about WSAC meetings after they are posted to this page, subscribe to the Washington Water Supply Email list.

Tacoma Old Town Dock. Photo by Wayne Hsieh, https://flic.kr/p/2pBqtCX

The Office of the Washington State Climatologist (OWSC) serves as one credible and expert source of climate and weather information for the state. Their monthly newsletter reviews the previous month’s data and details, as well as an introduction to the Natural Resources Conservation Service’s Snow and Water Interactive Map (iMAP), climate summary and outlook, and a link to reporting your observed drought impacts. Check out our Water Supply Monitoring page for additional sources.

Summary of recent conditions

February Climate Outlook: Weak La Niña conditions are expected to persist in the short term, but there is a higher chance (66%) of ENSO Neutral conditions returning during the March-April-May period, according to the CPC.
Last updated: Feb 20; next update (monthly): Mid-March.

The Washington State Climate Office (WASCO) is excited to announce a new website with improved usability and functionality. The most recent climate summary and outlook is in the February issue of the State Climatologist’s Newsletter.

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Climate Outlook from the state climatologist:

El Niño-Southern Oscillation (ENSO): Neutral ENSO conditions, La Niña likely by late fall/early winter

On January 9, the Climate Prediction Center (CPC) issued a “La Niña Advisory” due to La Niña being present in the tropical Pacific Ocean. Over the last month, sea-surface temperature anomalies have remained below normal in the central and east-central tropical Pacific Ocean. There has also been some development of above normal sea-surface temperature (SST) anomalies in the eastern tropical Pacific over the last month despite the status officially becoming La Niña. Below normal SSTs have strengthened below the surface of the ocean, however, and atmospheric conditions have reflected La Niña. The latest ENSO models are suggesting that La Niña will persist through the February-March-April period before potentially shifting back to neutral in the March-April-May period. The probability of La Niña during MAM is 39% compared to 60% for neutral conditions. In almost all scenarios, the event is expected to remain weak, and there can still be an influence on Washington’s average winter and spring conditions. La Niña is one of the many factors taken into account by the CPC outlooks highlighted below.

What does this mean for Washington in the coming months?

The CPC one month temperature outlook for February indicates higher chances of below normal temperatures across all of Washington, with the probabilities between 40 and 50% on the three-tiered scale for a majority of the state. The February precipitation outlook indicates higher chances of above normal precipitation across the state with the odds between 40 and 50% for the entire state.

The February-March-April (FMA) outlook is reflecting the typical La Niña influence on our weather. There’s between a 40 and 50% chance of below normal temperatures and between a 40 and 50% chance of above normal precipitation across the entire state.

For more information, see the Office of the Washington State Climatologist's Climate Outlook.

Last Updated: 2/11/2025

Data round-up: drought conditions summary

Below is a snapshot of wide variety of data sources that helps Ecology to understand evolving drought conditions. This will be updated regulary.

Forecasts continue to predict additional precipitation and colder temperatures for March,
- We see continued streamflow forecasts for April-September less than 75% of normal in parts of the North and Central Cascades, Olympic, Okanagan/ Methow and Yakima Basins.
While La Niña usually means wetter and colder, weak and late means less of an impact on our temperature and precipitation (CPC: ENSO Diagnostic).
- This pattern may depart by March, or stay into May.
The Yakima Basin, North and Central Cascades are an area of particular concern for drought recovery and compounding deficits after back-to-back droughts in 2023 and 2024. While the statewide SWE (snowpack measurement) map shows some better overall averages, there are individual SNOTEL (snow measuring) sites that are at less than 50% of average snowpack for this time in March. BOR reservoirs continue to be at 40% of average storage level, for this day in March (compared to 30-year normals). This is a concerning storage level in order to fill the gap in storage from back to back droughts in 2023 & 2024 and compounding deficits in precipitation for the area since October 2023.
BOR announced at a March 6 briefing that the March estimate for TWSA (Total Water Supply Available) is 48%.

The Washington State Climate Office - Climate Outlook

February Climate Outlook: Weak La Niña conditions are expected to persist in the short term, but there is a higher chance (66%) of ENSO Neutral conditions returning during the March-April-May period, according to the CPC.
Last updated: February 20; Next update (monthly): Mid-March

According to National Resources Conservation Science & U.S. Department of Agriculture

SWE Map – NWCC iMap
80% Statewide (Down 3% from last week), compared to normal Snow Water Equivalent (SWE); By Basin: WA Report or by maps: SWE by Basin – PDF (attached) or Interactive map
84% (Down 1% from last week) = Water YTD precipitation.
Last updated: March 10; Next update (daily): March 11. (Why does “SWE” matter – USDA Factsheet).

Last updated: March 12.

Bureau of Reclamation (BOR)

Yakima River system (Keechelus, Kachess, Cle Elum, Bumping, Rimrock) is at 24% of capacity and storage is at 40.2% of average.
BOR announced at a March 6 briefing that the March estimate for TWSA (Total Water Supply Available) is 48%.
Last updated: March 10; next update (daily): March 11.

Northwest River Forecast Center data and informaiton updates:

10 Day Meteorological Forecasts – Precipitation statewide and expected to be higher accumulation on the Westside in the latter half of the 10-day period.
Forecast report and Forecast map – Areas in North Cascades, Chelan, Okanogan/ Methow, and Central Cascades have April-Sept forecast below 75%. For April-September period, the Okanagan River is forecasted at 44% of normal, Methow at 40%, Stehekin at 62%, and Chelan at 54%.
NOTE: April – Sept forecasts are based on the next 10 days of forecast data, then based on climate normals from 1991-2020 average.

Lasted updated: March 10; Next update (daily): March 11.

National Oceanic and Atmospheric Administration (NOAA), National Weather Service (NWS) and Climate Prediction Center (CPC) data update:

8-14 day Outlook: Slight likelihood of above normal precipitation statewide, with leanin towards below normal temperature statewide.
- Valid: March 18-24, 2025, Issued: March 10, 2025
Three-month Temperature and precipitation outlook (March-April-May):
- Temperature: Probability slightly leaning towards below normal.
- Precipitation: Probability slightly leaning towards above normal.

Last updated: Issued Feb 20, 2025; next update (monthly) March 20, 2025.

National Integrated Drought Information System (NIDIS) Drought monitor

National Drought Monitor – Central and North Cascades, including the Eastside flanks such as the Yakima Basin continue to be in "D1" status, now with much of the Olympic peninsula as well. Full Westside to the eastern flank of the Cascades, along with far NE and far SE corners of the state are in "abnormally dry" status.
Reminder: Tool does not account for anticipated impacts on water supply from snowpack or BOR storage.
Updated: March 6 (U.S. Drought Monitor map is released every Thursday morning, with data valid through Tuesday at 10am PT).

United States Geological Survey (USGS) - WA Water Science Center:

National Water Dashboard –Mostly normal flow statewide.
Last updated: March 10; next update: March 11.

Other data tools used and updated:

Odds of 2024 Water Year Precipitation Reaching 100% - Central and North Cascades: Odds between 25-50% for reaching 100% of normal precipitation for water year 2025.
Climate Mapper – Mean Temperature & Precipitation Anomaly, last 30 days: Higher than normal temperatures in the Cascade and Olympic Mountains, with lower than normal temperatures in the westside valleys and east of the mountains. Precipitation percent or normal varies across the state, from 24-26% of normal in the Central Cascades and Olympic Mountains, to 81% of normal near Spokane.
PRISM Palmer Drought Severity Index – Continued drought concerns for central areas of the state.

Contact information

Caroline Mellor
Statewide Drought Lead
caroline.mellor@ecy.wa.gov
360-628-4666