#Drought #runoff news: D0 down to 4.78 % of #Colorado, all in SW

Click here to go to the US Drought Monitor website. Here’s an excerpt:


This U.S. Drought Monitor week saw widespread improvements in drought conditions primarily focused on northern California and Nevada while short-term precipitation deficits during the past 30–60 days led to some deterioration of conditions in parts of the Northeast, Pacific Northwest, and Southeast. During the past week, unseasonably cool temperatures dominated east of the Rockies while temperatures were above average in the Far West. Parts of the South continued in a wet pattern where a series of severe storms impacted South Texas with heavy rains (five-to-twelve inches) and localized flash flooding. Significant rainfall accumulations (two-to-five inches) also were observed in portions of the lower Midwest including southern Illinois, western Kentucky, and southern Missouri. Out West, conditions were generally drier, although some modest rainfall accumulations were observed across the Central and North Rockies as well as in the Pacific Northwest. In the Hawaiian Islands, beneficial rains fell in the drought-impacted coffee growing regions of South Kona on the Big Island, providing some relief…

The Plains

Across the Plains, improvements were made on the map in areas of Abnormally Dry (D0) in southeastern Kansas and north-central Oklahoma where recent rainfall improved area conditions. In southwestern South Dakota, short-term precipitation deficits in the Black Hills led to the introduction of an area of Moderate Drought (D1) that extended across the border into northeastern Wyoming. Temperatures were well below-normal across the entire region during the past week, especially in the Central and Northern Plains where temperatures were six-to-fifteen degrees below-normal. Precipitation across the region was heaviest in eastern portions of Kansas and Oklahoma where one-to-three inch accumulations occurred during the past week while northern portions were dry…

The West

During the past week, average temperatures were generally above-normal across much of the West with the exception of the northern Great Basin, central Rockies, and northern Rockies where temperatures were two-to-ten degrees below normal. Overall, the West was generally dry during the past seven-day period with the exception of isolated shower activity in the Central and Northern Rockies, and portions of the Pacific Northwest. With the conclusion of the snow season, statewide reservoir storage is above average in Colorado, Idaho, Montana, Washington, and Wyoming while near-normal levels are present in Oregon and Utah. Conversely, below-normal storage levels remain in Arizona, California, Nevada, and New Mexico, according to the Natural Resource Conservation Service.

On this week’s map, widespread one-category improvements were made across northern California and northwestern Nevada where conditions have steadily improved since the beginning of the Water Year (October 1st). In the northern Sierra, spring rains combined with a generally above-average snowpack have led to considerable increases in reservoir storage levels in area reservoirs. According to the California Department of Water Resources, Lake Oroville sits at 116% of its historical average while both Folsom Lake and Lake Shasta are at 108%. As of May 17th, the Northern Sierra 8-Station Index (a broad index of precipitation in the northern Sierra) is at 119% of average since the beginning of the Water Year. In southern California, precipitation accumulations since the beginning of the Water Year have been below-normal, especially in coastal areas of Los Angeles, Orange, and Ventura counties where the percentage of normal precipitation is less than 50% for the Water Year. In northwestern Nevada, a one-category improvement in a large area of Extreme Drought (D3) was made in response to a combination of short- and long-term indicators supporting improvements including: snowpack conditions, stream flows, reservoir storage levels, percentage of normal precipitation, and vegetative health. In the Pacific Northwest, a combination of short-term precipitation deficits (30-day) and above-normal temperatures led to the introduction of an area of Abnormally Dry (D0) in northwestern Oregon and western Washington where stream flow (28-day average) activity and soil moisture conditions are below-normal in many locations. In western Utah, a one-category improvement was made in an area of Moderate Drought (D1) where short- and long-term indicators show improvements in stream flows, groundwater levels, and soil moisture…

Looking Ahead

The NWS WPC 7-Day Quantitative Precipitation Forecast (QPF) calls for significant rainfall accumulations in the Gulf Coast, Mid-Atlantic, Southeast, and Texas with totals ranging from two-to-four inches. Otherwise, lesser accumulations are forecasted for extreme northern California, the Northern Rockies, and the Pacific Northwest. The CPC 6–10 day outlooks call for a high probability of above-normal temperatures east of the Rockies while the West is expected to be below-normal. Below-normal precipitation is forecasted for the Eastern Tier and Desert Southwest while there is a high probability of above-normal precipitation in the western portions of the Midwest and South, Northern Great Basin, Northern Rockies, Pacific Northwest, and across the Plains states.

From email from Reclamation (Peter Soeth):

Green Mountain has started to fill for the 2016 season and due to the higher snowpack and minimum available storage in Dillon Reservoir releases from Green Mountain will be increasing to 800 cfs over the next two days. Releases are expected to remain above 600 cfs for several weeks. Green Mountain Reservoir is currently 55% full and is anticipated to reach maximum fill around the second week of July.

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