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, but not with a high probability - and equal chances of above or below normals after 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.
- However, we have seen improvements in some (but not all) of the higher elevation sites in north and central Cascades. Lower elevation sites continue to be of concern.
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, the Methow/Okanogan and somewhat 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 have only risen to 41% of average storage level, for this time in March after being around 32% for much of the winter (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 May 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

March Climate Outlook: Weak La Niña conditions are expected to transition to neutral conditions in the next month. La Niña conditions continue to weaken driven in large part by warming sea surface temperatures in the central and eastern Tropical Pacific.
Last updated: March 20; Next update (monthly): Mid-April.

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

SWE Map – NWCC iMap
96% Statewide (Up 7% 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
89% (Up 4% from last week) = Water YTD precipitation.
Last updated: March 24; Next update (daily): March 25. (Why does “SWE” matter – USDA Factsheet).

Last updated: March 17.

Bureau of Reclamation (BOR)

Yakima River system (Keechelus, Kachess, Cle Elum, Bumping, Rimrock) is at 28% of capacity and storage is at 42.7% of average.
BOR announced at a March 6 briefing that the March estimate for TWSA (Total Water Supply Available) is 48%.
Last updated: March 24; next update (daily): March 25.

Northwest River Forecast Center data and informaiton updates:

10 Day Meteorological Forecasts – Precipitation throughout the next 10 days, with statewide reach in the later half of the period. High accumulation expected in the middle of the period, with the least amount in central and with temperatures turning from winter to spring.
Forecast report and Forecast map – Areas in Chelan and Okanogan/ Methow have April-Sept forecast below 75%. For April-September the period, the Okanagan River is forecasted at 56% of normal, Methow at 46%, Stehekin at 70%, and Chelan at 65%.
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 24; Next update (daily): March 25.

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 and temperature statewide.
- Valid: March 31-April 6, 2025, Issued: March 23, 2025
Three-month Temperature and precipitation outlook (April-May-June): equal chances of slightly below or above normal temperature and precipitation

Last updated: Issued March 20, 2025; next update (monthly) April 17.

National Integrated Drought Information System (NIDIS) Drought monitor

National Drought Monitor – Less of the Olympics are indicated as abnormally dry under this tool. Central and north Cascades, including now the western and eastside flanks continue to be in "D1" status. Portions of the westside, along with far NE and far SE corners of the state are also in "abnormally dry" status.
Reminder: Tool does not account for anticipated impacts on water supply from snowpack or BOR storage.
Updated: March 20 (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, with some lower than normal flow in the Okanogan.
Last updated: March 17; next update (daily): March 18.

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 across the state, with a higher magnitude in the Cascade and NE of the state. Precipitation slightly higher than normal across the state, with higher magnitudes in the farther north and south of the Cascade Mountains, and the Olympics, with some areas of below normal precipitation in the eastern flank of the Cascades.
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