#Drought news June 8, 2023: Heavy rains fell over parts of the #Colorado, #KS, #NE and S.E. #WY plains this week, leading to widespread one-category improvements

Click on a thumbnail graphic to view a gallery of drought data from the US Drought Monitor website.

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

This Week’s Drought Summary

Heavy rains fell this week across some of the western parts of the Central and Southern Great Plains, especially in the Texas Panhandle and western Oklahoma and Kansas, leading to widespread improvements to ongoing drought in the western Great Plains. Heavy rains in the central and southern Florida Peninsula also led to improvements to ongoing drought and abnormal dryness in the southwest Florida Peninsula. Widespread degradations occurred in the Midwest and western portions of the Northeast, amid very dry and warm recent weather. In the West, some minor improvements occurred in parts of Nevada, Utah and Idaho, where high streamflows and large precipitation amounts from the winter into May led to a reassessment of conditions. Degradations were made in a few parts of western Montana and northwest Washington, where precipitation deficits mounted amid declining soil moisture and streamflow…

High Plains

Heavy rains fell over parts of the Colorado, Kansas, Nebraska and southeast Wyoming plains again this week, leading to widespread one-category improvements in areas with increasing soil moisture and lessening precipitation deficits. After recent heavy rains, some improvements were also made in northeast and east-central Kansas. In eastern Nebraska, some heavier rains fell, but these were quite spotty, so drought areas remained mostly unchanged. Conditions improved in a small area southeast of Lincoln where rainfall amounts locally exceeded 4 inches. North of Omaha, extreme drought expanded slightly, as soil moisture and precipitation deficits worsened alongside poor streamflow. During May, Lincoln and Omaha both received much less than an inch of rainfall, and much of Saunders County received less than an inch of rain as well. Omaha’s May total of 0.17 inches of rain came in as the driest May on record there. In South Dakota, moderate and severe drought increased in coverage in the southeast, where short-term precipitation deficits mounted amid decreased streamflow and soil moisture. Rolling corn was reported north of Mitchell, and very dry soils were reported in far southeast South Dakota, where impacts to agriculture and need for irrigation are quickly ramping up…

Colorado Drought Monitor one week change map ending June 6, 2023.

West

Small-scale improvements were made in parts of southern and central Idaho, Nevada and northwest Utah, where high streamflows and large precipitation amounts from the winter into May led to a reassessment of conditions. Moderate and severe drought increased in coverage in northwest Montana and northwest Washington, where short-term precipitation deficits were occurring amidst low streamflow and decreasing soil moisture. In Oregon, a tight gradient in temperature and precipitation anomalies has been present recently, resulting in worsening conditions in the north and west portions of the state, while conditions have improved in the southeast part of Oregon. In some areas, streamflow and snow cover has quickly decreased as a result of early melt off and recent dry weather. Due to heavy rains associated with a storm system responsible for the heavy rain in the southern Great Plains, some improvements were also made in the plains of east-central New Mexico…

South

Relatively dry weather occurred this week in Arkansas, Tennessee, Mississippi and east-central and northeast Oklahoma. Farther west, in the Texas Panhandle, northwest Oklahoma and the eastern Oklahoma Panhandle, the recent wet pattern continued, and widespread 2- to 5-inch rains fell, with localized higher amounts. Widespread improvements were made to the drought and dryness depiction in this region, where soil moisture improved and precipitation deficits lessened. The rest of Texas saw a mixture of a few improvements and degradations, as heavier precipitation amounts around the state were more spotty. Farther east in eastern Oklahoma and northern Arkansas, abnormal dryness and moderate drought were introduced or expanded in areas that have recently seen growing short-term precipitation deficits, declines in soil moisture, and lowering streamflows…

Looking Ahead

For June 8-13, an inch or more of rain is forecast from the Pacific Northwest to the western interior, then across the central Plains, northern parts of the Southeast, and much of the Midwest. Local amounts up to or exceeding 3 inches of rain is forecast in northern and central Montana and the northern Rockies of Colorado. Far southern Florida may also see an inch or so of rain during this period. A quarter inch or more can be expected in the northern Plains into the western Midwest, the Northeast and the South from Texas to Florida. Little to no precipitation is predicted for the lower four-corners area and Pacific West Coast.

For the period from June 13-17, the National Weather Service Climate Prediction Center forecast favors below-normal precipitation across parts of the south-central and southeast United States, especially the central and western Gulf Coast areas into southwest Texas and southern New Mexico. Above-normal precipitation is favored in the Intermountain West and Great Basin, and with lesser confidence also favored from the Central Great Plains eastward into the Ohio Valley, Mid-Atlantic, and Northeast. Below-normal precipitation is favored in the Great Lakes vicinity. Above-normal precipitation is favored in most of Alaska, with the exception of the far southern reaches of the southeast Panhandle, where below-normal precipitation is more likely. Temperatures in Alaska are likely to be below normal in most areas, excluding the far north, with the highest forecast confidence centered over south-central and southeast Alaska. In the Lower 48, cooler-than-normal temperatures are favored in the Southwest and Intermountain West, excluding southeast New Mexico, and in the Upper Ohio River Valley. Warmer-than-normal temperatures are more likely in the north-central and northwest United States, especially in Minnesota and surrounding states, and from Texas and Oklahoma southeast into southern Alabama and Georgia and all of Florida.

US Drought Monitor one week change map ending June 6, 2023.

Just for grins here’s a slideshow of early June US Drought Monitor maps for the past few years.

Well above Normal Streamflow Volumes Observed Across #Colorado in May: Across Western Colorado streamflow volumes were near to above 200 percent of normal total monthly volumetric flow — NRCS #runoff

Mount Bierstadt May 27, 2023. Photo credit: NRCS Colorado Snow Survey

Click the link to read the release on the NRCS website:

Above normal streamflow volumes were observed in all major basins of Colorado during the month of May. Across Western Colorado streamflow volumes were near to above 200 percent of normal total monthly volumetric flow.

Denver, CO – June 7th, 2023 – Above normal streamflow volumes were observed in all major basins of Colorado during the month of May. Across Western Colorado streamflow volumes were near to above 200 percent of normal total monthly volumetric flow. Following the significant streamflow volumes during May the streamflow forecasts for the June through July period are for a lower percent of normal than the full April through July period. However, substantial volumes are still anticipated in many parts of the state. NRCS Hydrologist Karl Wetlaufer comments that “Even with significant snowmelt driven runoff in the month of May well above normal streamflow volumes are still anticipated through June and July particularly across much of the Western Slope and the Rio Grande Basin.” The averaged streamflow forecasts in the Colorado, Arkansas, and North Platte are for near normal volumes over the next two months but with considerable variability. Wetlaufer continued “The South Platte Basin should anticipate large discrepancies in June-July streamflow volumes between the drier mainstem headwaters and the tributaries of the Northern Front Range where flows are forecasted to be largely below, but much closer to normal volumes.”

Credi: NRCS Colorado Snow Survey

Ample streamflow in April and May has greatly improved reservoir storage volumes in the basins of Colorado that have struggled recently. Reservoir storage in the Gunnison and the combined San Miguel–Dolores-Animas-San Juan River basins has risen from about 70 percent of normal on April 1st to 100 and 92 percent, respectively, on June 1st. Wetlaufer notes “This month is the first time since May, 2020 that total reservoir storage in the State of Colorado is above the median volume for a given month. This is great news from a water supply standpoint both for this summer and going forward into future years.” Currently all major basins in Colorado are holding between 92 and 114 percent of normal reservoir storage for June 1st. These values will also likely continue to increase over the coming month in most basins of the state.

While we never fully know what the future may hold, so far Water Year 2023 has been a welcome reprieve from the previous three years with above normal snowpack, precipitation, and streamflow runoff across much of the state. Some areas that stand out as remaining drier than most include basins flowing out of the Sangre de Cristo Mountains and the headwaters of the main stem South Platte. That said, those regions have fared substantially better than Western Colorado with respect to accumulated precipitation over the last month, improving hydrologic and drought conditions. “In addition to how this water year has improved hydrologic conditions such as streamflow and reservoir storage, dramatic improvements have been observed in drought designations across the state since last fall” Wetlaufer concluded.

Colorado’s Snowpack and Reservoir Storage as of June 1st, 2023

Colorado’s Snowpack and Reservoir Storage as of June 1st, 2023
* San Miguel-Dolores-Animas-San Juan River basin
* *For more detailed information about February mountain snowpack refer to the June 1st, 2023 Colorado Water Supply Outlook Report. For the most up to date information about Colorado snowpack and water supply related information, refer to the Colorado Snow Survey website.

Aspinall Unit operations update June 7, 2023 #GunnisonRiver #COriver #aridification

Aspinall Unit dams

From email from Reclamation (Erik Knight):

The June 1st forecast for the April – July unregulated inflow volume to Blue Mesa Reservoir is 845,000 acre-feet. This is 133% of the 30 year average. Snowpack in the Upper Gunnison Basin peaked at 138% of average. Blue Mesa Reservoir current content is 625,000 acre-feet which is 75% of full. Current elevation is 7496 ft. Maximum content at Blue Mesa Reservoir is 828,00 acre-feet at an elevation of 7519.4 ft. 

High flows along tributaries downstream of the Aspinall Unit helped with meeting the Aspinall Unit ROD targets on the lower Gunnison River as measured at the Whitewater gage. Releases to meet ROD targets were lower than expected and with the increase in the runoff forecast there is now a need to increase releases from the Aspinall Unit.  

Therefore ramp up of releases from the Aspinall Unit will begin on Wednesday, June 21st, with the peak release being achieved by Tuesday, June 27th. The timing of the peak release will be coordinated with required spillway gate inspections at Morrow Point Dam. The full schedule of releases from Crystal Dam with estimated Gunnison River flows is shown in the table below. 

The June 1, 2023 #Colorado #Water Supply Outlook is hot off the presses from the NRCS

Click the link to read the report on the NRCS website: