PORTLAND, Ore. (KOIN) — We’ll likely see the upper 80s today and keep the mid-80s through Thursday. A weak disturbance passes through the PNW bringing cooler weather by Friday. And by “cooler” we mean morning clouds with afternoon temps in the upper 70s.
Weekend: Low 80s and mostly sunny Saturday. By Sunday, weather models are advertising the upper 80s to 90° in Portland! Monday will likely be the hottest day of the year if we can achieve 94°. The last time we were at least that warm was August 27th/28th of last year (98°). Hood to Coast, anyone?
Here’s an update on Oregon drought conditions and impacts provided by the National Weather Service Portland, as of July 14.
Drought conditions persist across most of Oregon, as depicted by the U.S. Drought Monitor. Almost half of the state is in severe or extreme drought, primarily affecting north-central, south-central, and southwest Oregon. Another quarter of the state is in moderate drought. The only part of Oregon not currently affected by drought or abnormally-dry conditions is northeast Oregon. For the latest drought monitor depiction, visit droughtmonitor.unl.edu.
What caused the drought? Above-average temperatures and below- average precipitation for most of the past nine months resulted in below-average mountain snowpack, low soil-moisture, and low streamflow, especially for central and southwest Oregon. What are the impacts of drought and abnormally-dry conditions around the state as of early July? Impacts include 1) below-average streamflow, with which leads to supply shortages, increases in water temperature, and declines in water quality and in-stream habitat conditions, 2) low reservoir storage, especially in central and southwest Oregon, which will likely affect irrigation allotments and reduces recreational opportunities, and 3) stressed vegetation, both for rangeland and forest conditions, which reduces grazing availability and increases fire and insect-damage susceptibility. These impacts are most severe in the Klamath, Deschutes, Rogue, Coquille, and Umpqua watersheds.
What is the outlook for summer weather conditions? According to the Climate Prediction Center, there is an enhanced likelihood of above- average temperatures, and summer precipitation is typically negligible statewide. All in all, no relief from drought conditions is likely until the fall, at the earliest. For more details on monthly and seasonal outlooks, visit www.cpc.ncep.noaa.gov. Visit drought.gov for more details on drought conditions and categories in Oregon and the Pacific Northwest.
As of early July, the following counties have drought emergency declarations in effect from Oregon Governor Brown: Coos, Crook, Curry, Deschutes, Douglas, Gilliam, Jackson, Jefferson, Josephine, Klamath, and Wasco. Visit www.oregon.gov/owrd/pages/wr.drought.gov for details on county declarations. The next update of this Drought Information Statement will be issued by August 10, 2020.
Observed Precipitation and Temperatures Water-year precipitation thus far (October 2017 – June 2018) is lowest in southwest and central Oregon and highest in northeast Oregon. Values are 40 to 65 percent of normal for southwest Oregon, 50 to 75 percent of normal for north-central and south-central Oregon, 60 to 100 percent of normal for southeast Oregon, 70 to 100 percent of normal for northwest Oregon, and 90 to 120 percent of normal for northeast Oregon. Temperatures December 2019 through May 2020 were above-average statewide. Temperatures in June 2020 were near average. Visit www.nwrfc.noaa.gov/water_supply/wy_summary/wy_summary.php for more details on observed precipitation and temperatures.
The Climate Prediction Center produces monthly and seasonal outlooks, in which there is a weighing of the odds of near-normal, above-normal, or below-normal temperatures and precipitation. For July through September, precipitation is typically negligible in terms of water supply. Summer thunderstorms can provide isolated short-term drought relief, but in general, widespread precipitation is unlikely until late September. Temperatures for the mid and late July are expected to be above- average, as high pressure builds over the Pacific Northwest. The three-month temperature outlook for July through September calls for an enhanced likelihood of above-average temperatures across Oregon. Visit www.cpc.ncep.noaa.gov for details about monthly and seasonal outlooks.
Reservoir conditions are highly variable around the state, but the big message is that dry and warm conditions this winter and spring resulted in low storage for reservoirs in central and southwest Oregon. Reservoirs that are notably low include Applegate in southwest Oregon at 48 percent of capacity; Prineville, Ochoco, and Wickiup Reservoirs in central Oregon, at 55, 37, and 31 percent of capacity, respectively; and Warm Springs and Beulah Reservoirs in eastern Oregon, at 63 and 59 percent of capacity, respectively. All irrigation reservoirs are releasing more than inflow, and reservoir storage levels will continue to drop through the summer. Some reservoir may go to minimum pool and have to restrict releases later this summer. Many reservoirs will have low or no carry-over storage leading into the fall. Visit www.usbr.gov/pn/hydromet/select.html and www.nwd- wc.usace.army.mil/nwp/wm/teacups.html for more information.
Streamflow Conditions Streamflow in June was near-average for western and eastern Oregon but below-average for central Oregon. Looking at the water year, streamflow has been well below-average. Water-year runoff ranges from 35 to 60 percent of average in southwest Oregon and 30 to 50 percent of average in central Oregon, the areas most affected by drought. Visit waterwatch.usgs.gov for details on observed streamflow in recent months and www.nwrfc.noaa.gov/ws/index.html for water year runoff data.https://water.weather.gov/ahps/water/textprods/view.php?wfo=pqr&prod=DGT
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