#Drought news: “This is the first week in the entire history of the #DroughtMonitor…that #Colorado is 100% free of D0-D4 categories. Perhaps I’ll frame it.” — @ClimateBecky

Click on a thumbnail graphic to view a gallery of U.S. Drought Monitor data.

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

This Week’s Drought Summary

During this U.S. Drought Monitor (USDM) week, a strong high pressure ridge was anchored over the southeastern contiguous U.S. (CONUS) while an upper-level trough dominated the West. This pattern set up a southwesterly flow across the central part of the country, which funneled moist and unstable air from the Gulf of Mexico into the Plains. Pacific weather systems moving in the jet stream flow plunged into the western trough, bringing precipitation and cooler-than-normal temperatures to much of the country from the Rockies westward. The weather systems intensified as they moved into the Plains, triggering another week of severe weather and heavy flooding rains. Two or more inches of precipitation occurred across the Plains to Midwest and in upslope areas of Montana and Wyoming, with locally 5 inches or more. Weekly precipitation was wetter than normal across much of the Southwest, and from much of the Great Plains to Great Lakes. Half an inch to locally 2 inches was observed from the central Appalachians to New England, but these amounts were mostly below normal. The week ended up drier than normal across western Washington, northern Idaho and northern Montana, southern Arizona, most of New Mexico, and central to southern Texas. The subtropical high kept the Southeast drier and warmer than normal, with record high temperatures reported. As a result of this weather pattern, drought contracted in Oregon, Wyoming, and the central Plains, but expanded in the northern Rockies, Texas, the Tennessee Valley, and the Southeast…

High Plains

The central to northern Plains received 2 or more inches of precipitation across a large area from Kansas to Wyoming and southern Montana, with 5 or more inches measured in Kansas and Nebraska. An inch to 2 inches occurred to the north and in parts of Wyoming, with less than a half inch measured in southwest Wyoming and northwest North Dakota to north central Montana. The precipitation deleted D0 in southwest Nebraska and D1 in the Big Horn Mountains of Wyoming and shrank the surrounding D0. But D0 expanded across the northwest corner of North Dakota into northeast Montana where 90-day precipitation deficits were notable. Windy conditions and sparse rain have dried soils in Daniels and Sheridan Counties in Montana, with fire risk increasing. Soils were drying in northern North Dakota and some sloughs and ponds had low water levels. An inch or more of rain this week prevented the expansion of D0 and addition of D1 in northern North Dakota this week, but it may be considered for next week…

West

D0-D1 remained in parts of Arizona and New Mexico, and D0 remained in southern California, both reflecting long-term dryness which has built up over the last 5 to 6 years (and low reservoirs in southern California), and in Washington to northwest Oregon. Precipitation was above normal in southeast Oregon at most time scales, so the D0 there was deleted. But in western Washington to northwest Oregon, this week was dry and most of the last 1 to 2 years have been drier than normal, mountain snowpack was diminished from normal values for this time of year, and streamflow was much below normal to record low. D0-D1 here reflected these conditions for now, but D2 may be needed if conditions worsen. D0-D1 expanded in the Rockies of northeast Oregon, far northern Idaho, and northwest Montana where streamflow and precipitation and SPI values for the last 4 months were low…

South

Precipitation amounts in the South ranged from zero in parts of Texas, Louisiana, Mississippi, and Tennessee, to over 5 inches in northern Oklahoma. D0 expanded in central Tennessee where 90-day precipitation deficits were noteworthy, pockets of D0 expanded or were introduced in southern Texas along the Rio Grande or along the coast, and D1 was added to Zavala County in Texas where dryness was evident for the last 7 days to 6 months. According to USDA reports, 21% of the topsoil moisture in Tennessee was short or very short, up from 3% last week. The last couple weeks have been very dry, hot, and windy in southern Texas as the subtropical ridge continued to build and dry out the atmosphere. There have been reports of significant evaporation of Cameron County retention ponds with fields and lawns showing some browning. Some producers in Dimmit County, Texas were hauling water and supplemental feeding in some areas…

Looking Ahead

Next week (May 30-June 4), an upper-level weather system will move across the eastern CONUS while another takes up residence over the Southwest. The high pressure ridge over the Southeast gradually shifts to the Plains. During this process, fronts and low pressure systems will trigger heavy rains again across the Plains to Midwest, with 1 to locally over 3 inches progged from northern Texas to Illinois, and from Illinois to Pennsylvania. An inch or more of precipitation is expected over much of the Northeast. Little to no precipitation is forecasted for much of the Southeast, most of California, the western half of the 4 Corners States, western Oregon, much of Washington, the High Plains of Wyoming and Montana, most of North Dakota, and northern Minnesota. Above-normal temperatures will continue in the Southeast for much of this period, and spread from the Pacific Northwest into the northern and central Plains, while cooler-than-normal temperatures will linger in the Southwest and from the eastern Great Lakes to New England. For June 5-12, odds favor above-normal precipitation from the 4 Corners States to the southern Appalachians, eventually spreading across the Southeast; along most of the Mississippi River; and over the northern half of Alaska, including the panhandle. Statistical odds favor drier-than-normal weather over the Great Lakes to Northeast, from northern California to the northern High Plains, and over southwestern Alaska. Cooler-than-normal weather is expected across New Mexico to western Texas, over Washington State, from the Great Lakes to New England, and over central Alaska. There is a high probability for warmer-than-normal weather over the northern to central Plains stretching into California, over the Southeast stretching to the Gulf of Mexico coast and Mid-Atlantic coast, and over southern and northern Alaska.

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