#Drought news: May rains lead to a 1-category improvement in southeastern Colorado

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

Summary

A series of cold fronts moving southeastward out of the Canadian Prairies brought additional moderate to heavy (more than 2 inches) rains to the water-logged southern and central Plains, including most of Kansas, Oklahoma, and Texas, along with beneficial moisture to the northern Plains and Midwest, early in the period. Based upon estimated monthly state rainfall totals, May 2015 was the wettest month ever in Texas (8.81 inches) and Oklahoma (14.27 inches), incredibly ending the region’s long-term drought within 4-6 weeks (but causing widespread flooding). Over the weekend as a strong cold front finally pushed eastward, the southern half of the Plains finally cleared out while much of the Southeast, mid-Atlantic, and New England reported welcome showers and thunderstorms which ended the unseasonable warmth and eased short-term dryness. Dry conditions and increasing temperatures returned to the Southwest after an unseasonably cool and wet May that led to unexpected green-up of ranges and pastures in parts of southern and eastern California, Nevada, and western Arizona but did nothing to ease the long-term drought, and most-likely added extra fuel for late summer and early fall wildfires once the vegetation dies off. Light showers were enough to keep the Pacific Northwest at status-quo, while a very warm and record dry May (after a wet April), along with little to no spring snowpack, was enough to expand D0 along the southeastern Panhandle of Alaska. Continued subnormal rains across eastern Puerto Rico and low stream flows justified expansion of D0 and D1, and the addition of D2…

Great Plains

The incredible southern Plains drought relief continued this week, although the weekly rainfall amounts “decreased” from copious to heavy, and clear skies finally prevailed later in the period. Still, more than 2 inches of rain fell on parts of the Dakotas, western Nebraska, western and eastern Kansas, eastern Oklahoma, and most of Texas except for the Panhandle and southwest. The week’s heaviest rains fell around the Dallas-Ft. Worth region, with locally up to 8 inches. Based upon estimated monthly state averages, May 2015 was the wettest month ever for Texas (8.81 inches) and Oklahoma (14.27 inches), breaking both the former state monthly records by several inches. This has alleviated long-term drought within 4-6 weeks, but unfortunately produced widespread severe flooding. Monitored Texas water supply reservoirs were 83.4% full on June 3, whereas 6-months ago they were at 62.5% full. A few reservoirs in the Panhandle and west-central Texas were still below normal (where D0 and one small D1 area was kept), but nearly every reservoir in the eastern half of the state was close to capacity. With the continued moisture, decreasing or eliminated long-term deficits, and increasing short-term surpluses, 1-category improvements were made across much of Texas, Oklahoma, western and southern Kansas, southeastern Colorado, eastern South Dakota, and northeastern and southwestern North Dakota. Where lighter rains fell (north-central Oklahoma, south-central Kansas, eastern Nebraska, and south-central South Dakota), conditions were maintained. D0 was slightly expanded in northwestern North Dakota (Mountrail County) where long-term dryness still lingered…

The West

Seasonably drier and warmer weather returned to the West after unseasonably cool and unsettled conditions occurred during the first 3 weeks of May. As a result, May recorded above-normal precipitation (except along the Pacific Coast) and well below-normal temperatures (except in the Pacific Northwest). With May precipitation normally low, it didn’t take much rainfall to produce well-above normal percentages (e.g. San Diego, CA obs=2.39”, normal=0.12”). An unusual effect of the cool and wet May weather was a green-up of pasture and range vegetation in southern and eastern California and Nevada where extreme to exception drought is widespread and ongoing. Although California and Nevada pasture and range conditions were rated 35% and 50% good or very good on May 31 by the USDA, no improvements were made to the drought depiction as long-term (4-year drought) hydrologic conditions remained dire. In fact, the green-up of vegetation and sprouting of grasses will most-likely provide extra fuel for wildfires once the vegetation dies off later this summer. To depict the short-term wetness, the impact line between SL and L was drawn where May was wet (L-only) versus May was dry (SL) from central Washington southward into southern California. In western and central San Bernardino County, the May rains missed this desert region, and with conditions similar to areas to the immediate west, D3 was expanded into this county. In southwestern Montana, areas west of the divide did not receive the May rains that east of the divide enjoyed, thus D0 was expanded into this region. In contrast, areas east of the divide and north of Yellowstone saw excess May rains, and D1 and D0 was trimmed away there. Elsewhere, no changes were made as light precipitation across the Northwest and eastern Great Basin was enough to maintain status-quo…

Looking Ahead

For the upcoming 5-day period (June 4-8), decent precipitation should occur across the Great Basin, north-central Rockies, central and northern Plains, most of the Midwest and Great Lakes region, and along most of the southern Atlantic Coast States (from Florida northward into Virginia). Little or no rainfall is expected in the Far West, Southwest, southern third of the Plains, and coastal New England. Temperatures should average above-normal in the Northwest, southern half of the Plains, middle and lower Mississippi, and Ohio Valleys. Elsewhere it should be near or slightly below normal.

For the ensuing 5-day period (June 9-13), the CPC 6-10 day outlooks, odds favor above-median precipitation in the Southwest, Great Basin, central Rockies and Plains, eastern third of the Nation, and northern Alaska, with subnormal precipitation likely in the Northwest, northern and southern Plains. Above-normal temperatures are favored in the West, northern Plains, and in the Southeast and along the Eastern Seaboard, with subnormal readings limited to central Alaska.

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