Drought Information Statement for Eastern OR & South Central WA Valid March 15, 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. Moderate drought is affecting portions of central Oregon into north central Oregon and Wallowa county. Mountain snowpack has been growing steadily owing to storms over the January through March time period. Northwest Geographic Area denotes the potential for significant fires will remain minimal or low risk until late June or July. U.S. Drought Monitor National Weather Service Pendleton, OR Drought intensity and Extent D1 (Moderate Drought): Portions of central Oregon into north central Oregon and Wallowa County. D0: (Abnormally Dry): Northern Blue Mountains of OR and WA, Wallowa, central OR, north central OR, and much of the eastern slopes of the Washington and Oregon Cascades. Recent Change in Drought Intensity National Weather Service Pendleton, OR One-Week Drought Monitor Class Change No Change Four-Week Drought Monitor Class Change Drought Worsened (1 Class Degradation): Portions of the upper eastern slopes of the Washington Cascades and the Northern Blue Mountains. Drought Improved: Limited portions of central and north central Oregon. Image Captions: Right - 4 Week Drought Class Change Left - 1 Week Drought Class Change Data Courtesy U.S. Drought Monitor and Drought.gov Precipitation - Last 30 Days National Weather Service Pendleton, OR Below normal precipitation across south central WA south into portions of the eastern Columbia River Gorge and portions of the foothills of the Blue Mountains. The areas of below normal could attributed to recent weather systems and their attendant atmospheric rivers that have impacted mainly northern CA, the Pacific NW coast, and central/southern OR. Above normal precipitation mostly across parts of central OR and the central OR mountains. 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 March 13, 2024 Precipitation - Current Water Year National Weather Service Pendleton, OR 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 March 11, 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). Temperature - Last 30 Days National Weather Service Pendleton, OR Predominantly near normal average temperature the last 30 days. Average low temperatures were slightly above normal across parts of south central WA and central OR, near normal elsewhere. Average high temperatures were near normal, except for pockets of below normal across areas of 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 March 14, 2024 Summary of Impacts National Weather Service Pendleton, OR Hydrologic Impacts Below normal streamflow 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. Snowpack Impacts There are no known impacts at this time with sites reporting slightly below normal mountain snowpack across the Washington Cascades between 70-89%. Agricultural Impacts There are no known impacts at this time. Fire Hazard Impacts There are no known impacts at this time. Other Impacts No Oregon Drought declarations. No Washington Drought Advisories or Drought emergencies. 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 Hydrologic Conditions and Impacts - Washington National Weather Service Pendleton, OR Image Captions: Right - USGS 7-day average streamflow station map valid March 14, 2024 Left - USGS 7-day average streamflow HUC map valid March 14, 2024 Data Courtesy USGS Water Watch Main Takeaways Upper Columbia-Priest Rapids and Lower Yakima basins have 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 - Oregon National Weather Service Pendleton, OR Main Takeaways All reporting river, stream, and creek flows (left) across eastern and central OR are normal or above normal. The Lower Crooked basin in central OR is considered above normal with the Crooked River below Opal Springs reporting above the 75th percentile (141% percent of normal / median). 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 March 14, 2024 Left - USGS 7-day average streamflow HUC map valid March 14, 2024 Data Courtesy USGS Water Watch Snowpack Conditions and Impacts National Weather Service Pendleton, OR Main Takeaways Mountain snowpack has been growing steadily across much of the Cascades and mountains of Oregon and Washington owing to storms over the January through March time period. Above normal snowpack is seen across the OR Cascades and across central OR into the southern Blue Mountains. Much of the mountain snowpack across Washington and northeastern OR is below normal between 70-89%. 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 March 15, 2024 Water Supply Forecast - April - September 2024 National Weather Service Pendleton, OR Main Takeaways Most locations across south central WA and eastern OR are forecast to see near or slightly above or below normal water supply. Areas across the Ochoco-John Day Highlands and parts of the Northern Blue Mountains are forecast to see above-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 3-15-2024 Forecast (% of Normal) Fire Hazard Impacts - March, April, and May National Weather Service Pendleton, OR Main Takeaways Near normal (i.e., very low) risk of significant wildland fire potential through June 2024. Identical forecasts of normal wildland fire potential from March 2024 through June 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 - March 2024 Right - May 2024 Data Courtesy National Interagency Coordination Center Seven Day Precipitation Forecast National Weather Service Pendleton, OR Dry weather and above normal temperatures will prevail through Tuesday (Day 4) owing to upper-level high pressure dominating the weather pattern. Renewed potential for precipitation and mountain snow starting Wednesday (Day 5) as the synoptic pattern looks more likely than not to transition as high pressure breaks down and gets shunted to the east. Visit weather.gov/Pendleton for the latest weather forecast Image Caption: Weather Prediction Center 7-day precipitation forecast 6-10 Day Outlook National Weather Service Pendleton, OR Main Takeaways Leaning above normal area-wide with a greater shift in the odds towards southeast Oregon (40-50%). Tilted slightly towards above normal for above average precipitation (33-40%). Image Captions: Left - Climate Prediction Center 6-10 Day Temperature Outlook. Right - Climate Prediction Center 6-10 Day Precipitation Outlook. Valid March 20-24, 2024 8-14 Day Outlook National Weather Service Pendleton, OR Main Takeaways Slight tilt in the odds for below normal temperatures towards eastern WA (33-40%). Leaning above normal for above average precipitation (33-40%). Image Captions: Left - Climate Prediction Center 8-14 Day Temperature Outlook. Right - Climate Prediction Center 8-14 Day Precipitation Outlook. Valid March 22-28, 2024 Monthly Climate Outlook National Weather Service Pendleton, OR Image Captions: Left - Climate Prediction Center Seasonal Temperature Outlook. Right - Climate Prediction Center Seasonal Precipitation Outlook. Valid March 2024 Main Takeaways Equal chances of above, below, or near normal temperatures. Odds tilted slightly for above normal precipitation (33-40%) across central OR and the central OR mountains. Seasonal Climate Outlook National Weather Service Pendleton, OR Image Captions: Left - Climate Prediction Center Seasonal Temperature Outlook. Right - Climate Prediction Center Seasonal Precipitation Outlook. Valid March, April, and May 2024 Main Takeaways Likely above normal temperatures area-wide with highest odds across parts of south central WA (60-70%). Odds leaning for below normal precipitation with the highest odds across eastern WA into extreme northeast OR (40-50%). Drought Outlook National Weather Service Pendleton, OR Main Takeaways Drought is expected to persist. Drought conditions anticipated to develop through the spring across parts of south central WA and the eastern mountains, and parts of extreme southeast WA and northeast OR. These areas are vulnerable given the current low snowpack conditions in tandem with the warm seasonal outlook. 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 March 15, 2024 Right - Climate Prediction Center Seasonal Drought Outlook Released March 15, 2024 The latest monthly and seasonal outlooks can be found on the CPC homepage.