Drought Information Statement for Eastern OR & South Central WA Valid April 12, 2024 Issued By: NWS Pendleton Contact Information: pdt.operations@noaa.gov This product will be updated if drought conditions change significantly. Please see all currently available products at https://drought.gov/drought-information-statements. Please visit https://www.weather.gov/pdt/DroughtInformationStatement for previous statements Please visit https://www.drought.gov/drought-status-updates/ for regional drought status updates. Moderate drought is affecting portions of central Oregon and central WA Cascades Mountain snowpack is below normal across south central Washington to southeast WA Northwest Geographic Area denotes the potential for significant fires will remain minimal or low risk until late June or July 1 Link to the latest U.S. Drought Monitor Drought intensity and Extent D1 (Moderate Drought): Portions of central Oregon and portions of the central Washington Cascades D0: (Abnormally Dry): Northern Blue Mountains of OR and WA, Wallowa county, the Grande Ronde Valley, parts of central OR, north central OR, and much of the eastern slopes of the Washington and Oregon Cascades U.S. Drought Monitor Link to the latest 4-week change map for the Pacific Northwest National Weather Service Pendleton, OR One-Week Drought Monitor Class Change Drought Improved: Eastern Wallowa county Four-Week Drought Monitor Class Change Drought Worsened (1 Class Degradation): Portions of the upper eastern slopes of the Washington Cascades Drought Improved: Limited portions of central and north central Oregon and eastern Wallowa county Image Captions: Right - 4 Week Drought Class Change Left - 1 Week Drought Class Change Data Courtesy U.S. Drought Monitor and Drought.gov Recent Change in Drought Intensity Above to near normal precipitation across north central OR and the western Lower Basin While there has been rounds of rain and mountain snow, they have been mainly light with below normal precipitation seen across much the Cascades, eastern mountains and central OR mountains While weather systems and their attendant atmospheric rivers have mainly impacted the Pacific NW coast central and southern CA, the Blue mountains and Wallowa have seen near to above normal precip the last two weeks Image Captions: Right - Precipitation Amount for Pacific NW Left - Percent of Normal Precipitation for Pacific NW Data Courtesy High Plains Regional Climate Center Data over the past 30 days ending April 10, 2024 Precipitation - Last 30 Days Image Captions: Right - Precipitation Amount for Pacific NW Left - Percent of Normal Precipitation for Pacific NW Data Courtesy High Plains Regional Climate Center Data for the current water year ending April 10, 2024 Below normal precipitation seen over October and November 2023 continue to affect the current water year as a whole, especially across the WA Cascades were deficits exceeded 2-4 inches in spots each month Areas of above normal precipitation across the lower elevations of the interior Pacific NW could largely be attributable to January 2024 where percent of normal precipitation commonly exceeded 150% (surpluses of 0.5-1 inches and more) Precipitation - Current Water Year Predominantly near normal to above normal average temperature the last 30 days Average low temperatures were slightly above normal except for slightly below normal in central and north central OR and the Ochoco Mountains Average high temperatures were near to a few degrees above normal, except for a pocket of below normal temperatures across portions of north central OR Image Captions: Right - Temperature for Pacific NW Left - Percent of Normal Precipitation for Pacific NW Data Courtesy High Plains Regional Climate Center Data for the last 30 days ending April 10, 2024 Temperature - Last 30 Days Hydrologic Impacts Below normal streamflow (70-95%) for some streams and rivers across portions of Washington and eastern Oregon, including Upper Columbia-Priest Rapids and Lower Yakima basins, as well as low reservoir levels for some area reservoirs - this may affect fish and other aquatic species as well as recreation activities through spring and into summer. Further south, near to slightly above normal streamflows in Oregon Snowpack Impacts There are no known impacts at this time with sites reporting below normal mountain snowpack (70-80%) across the Washington Cascades with the exception of 56% for the Lower Yakima Basin Agricultural Impacts There are no known impacts at this time Fire Hazard Impacts There are no known impacts at this time Other Impacts Oregon - Jefferson County has requested a Drought Declaration Washington Drought Emergency declared for portions of Kittitas, Yakima, Benton, Klickitat, Walla Walla and Columbia Counties Mitigation actions Please refer to your municipality and/or water provider for mitigation information See/submit Condition Monitoring Observer Reports (CMOR) and view the Drought Impacts Reporter Summary of Impacts Image Captions: Right - USGS 7-day average streamflow station map valid April 10, 2024 Left - USGS 7-day average streamflow HUC map valid April 10, 2024 Data Courtesy USGS Water Watch Main Takeaways The Upper Columbia-Priest Rapids basin has below normal streamflow Most river, stream, and creek flows (left) across south central and southeast Washington are considered normal Impacts No known impacts at this time Reduced streamflow may be detrimental to aquatic species and recreational activities. Hydrologic Conditions and Impacts - Washington Main Takeaways All reporting river, stream, and creek flows (left) across eastern and central OR are normal, except below normal for Meacham Creek at Gibbon and above normal for Wallowa River near Joseph Impacts No known impacts at this time Reduced streamflow may be detrimental to aquatic species and recreational activities. Image Captions: Right - USGS 7-day average streamflow station map valid April 10, 2024 Left - USGS 7-day average streamflow HUC map valid April 10, 2024 Data Courtesy USGS Water Watch Hydrologic Conditions and Impacts - Oregon Main Takeaways Mountain snowpack is at or has past their peak across much of the Cascades and mountains of Oregon and Washington Above normal snowpack is seen across the OR Cascades and across central OR into the southern Blue Mountains Much of the mountain snowpack across south central Washington to southeast WA is below normal between 70-90% This includes the Naches, Upper/Lower Yakima, northern Blue mountains of WA, and Lower Grande Ronde basins Impacts No known impacts at this time Snow water equivalent is related to the amount of water stored in snowpack. The lack of snow can affect the amount of available water for spring and summer snow melt. This can have impacts on water storage, irrigation, fisheries, vegetation, municipal water supplies, and wildfire. Image Captions: Oregon and Washington SNOTEL Current Snow Water Equivalent % of Normal Data Courtesy USDA Natural Resources Conservation Service Daily Value as of April 11, 2024 Snowpack Conditions and Impacts Main Takeaways Most locations across south central WA and eastern OR are forecast to have a near or below normal water supply Areas across the Ochoco-John Day Highlands and parts of the Northern Blue Mountains are forecast to have a near to above normal water supply A few locations, mainly in the Blue Mountains and eastern Columbia Basin are forecast to have a well below normal water supply Impacts No known impacts at this time Low reservoir levels would be expected to affect agriculture production, fish, and other aquatic species. Image Caption: Ensemble Streamflow Prediction Natural Forecast Data Courtesy NOAA NWS Northwest River Forecast Center Issued 4-10-2024 Forecast (% of Normal) Link to the latest Northwest River Forecast Center Water Supply Forecast. Water Supply Forecast - April - September 2024 Main Takeaways Near normal (i.e., very low) risk of significant wildland fire potential through July 2024 Identical forecasts of normal wildland fire potential from April 2024 through July 2024 The Northwest Geographic Area denotes the potential for significant fires will remain minimal or low risk until late June or July. Image Caption: Left - April 2024 Right - June 2024 Data Courtesy National Interagency Coordination Center Link to Wildfire Potential Outlooks from the National Interagency Coordination Center. Fire Hazard Impacts - March through June An upper low and trough will bring a chance of showers and thunderstorms over the eastern Oregon mountains Friday through the weekend (Days 1-3) with mainly light precipitation An unsettled weather pattern will continue next week (Days 4-6) with light precipitation and below normal temperatures expected High pressure is expected Thursday into the weekend (Days 7-9) with fair and dry weather anticipated Visit weather.gov/Pendleton for the latest weather forecast Image Caption: Weather Prediction Center 7-day precipitation forecast Seven Day Precipitation Forecast Main Takeaways Leaning towards below normal temperatures area-wide with a greater shift in the odds towards the east (33-50%) Leaning towards below normal precipitation area-wide with greater odds along the Oregon Cascades and central Oregon (40-60%) Image Captions: Left - Climate Prediction Center 6-10 Day Temperature Outlook. Right - Climate Prediction Center 6-10 Day Precipitation Outlook. Valid April 17-21, 2024 Link to the latest Climate Prediction Center 6 to 10 day Temperature Outlook and Precipitation Outlook. 6-10 Day Outlook Main Takeaways Tilted in the odds for above normal temperatures (40-60%) Leaning towards below normal precipitation (33-50%) Image Captions: Left - Climate Prediction Center 8-14 Day Temperature Outlook. Right - Climate Prediction Center 8-14 Day Precipitation Outlook. Valid April 19-25, 2024 Link to the latest Climate Prediction Center 8 to 14 day Temperature Outlook and Precipitation Outlook. 8-14 Day Outlook Image Captions: Left - Climate Prediction Center Seasonal Temperature Outlook. Right - Climate Prediction Center Seasonal Precipitation Outlook. Valid April 2024 Main Takeaways Odds tilted for above normal temperatures (40-50%) Odds tilted for slightly below normal precipitation (33-40%) western portions of the area and equal chances of below normal, near normal and above normal precipitation in eastern portions of the area Link to the latest Climate Prediction Center Monthly Outlook. Monthly Climate Outlook Image Captions: Left - Climate Prediction Center Seasonal Temperature Outlook. Right - Climate Prediction Center Seasonal Precipitation Outlook. Valid April, May and June 2024 Main Takeaways Likely above normal temperatures area-wide (50-60%) Odds leaning for below normal precipitation across central OR and WA (33-40%) and equal chances of below normal, near normal and above normal precipitation in eastern OR and WA Link to the latest Climate Prediction Center Seasonal Outlook. Seasonal Climate Outlook Main Takeaways Drought is expected to persist in central Oregon These areas are vulnerable given the current low snowpack conditions in tandem with the warm seasonal outlook Drought is expected to develop in eastern Wallowa county Possible Impact Reduced streamflows and reservoir levels, possible reduction in agricultural yield, crop loss, and poor pasture conditions where irrigation water is not available. Image Captions: Left - Climate Prediction Center Monthly Drought Outlook Released April 11, 2024 Right - Climate Prediction Center Seasonal Drought Outlook Released April 11, 2024 The latest drought outlooks can be found on the CPC homepage. Drought Outlook