#Drought news: D0 expanded into Larimer, Boulder, and Gilpin counties due to recent dryness

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

Summary

A ridge of high pressure across the South and a trough of low pressure over the Northwest combined for an active storm track along the northern tier of the U.S. into the Midwest and southeastward into the Tennessee Valley. As numerous cold fronts tracked from the Northwest and southwestern Canada into the Nation’s mid-section and encountered the Southern ridge, they would stall and generate bands of heavy showers and thunderstorms. The week’s greatest totals fell on western and southern Kentucky, south-central North Dakota, central Minnesota, and northwestern Wisconsin where 4-8 inches (locally over 10 inches) was measured. Elsewhere, light to moderate rains occurred in the northwestern quarter of the U.S., most of the northern two-thirds of the Great Plains, upper Midwest, western Corn Belt, Tennessee Valley, portions of the Southeast, most of the Carolinas, and sections of the Northeast. Mostly dry weather enveloped the southwestern quarter of the Nation, the southern Plains, most of Florida, the Ohio Valley and eastern Great Lakes region, and mid-Atlantic. Weekly temperatures averaged below normal in the West, northern Plains, parts of the Midwest, and in New England. Positive temperature anomalies were found in the southern half of the Plains, across the Southeast, mid-Atlantic, and eastern Great Lakes region, with excessive heat (anomalies more than +6 degs F and triple-digit highs) in the southern High Plains. Precipitation decreased in Alaska as compared to last week (except in east-central sections), windward showers continued across Hawaii, and most of Puerto Rico saw light to moderate showers except for drier weather in south-central and southwestern sections of the island…

Plains

Several storm systems from the Pacific Northwest and southwestern Canada dropped moderate to heavy rain (1-5 inches, locally 8 inches) on Montana, North Dakota, and parts of South Dakota, providing a 1-category improvement where the totals exceeded 2 inches. While much of the heaviest rain fell on non-drought areas of the Dakotas, some D0 and D1 were improved in southwestern North Dakota (Morton, Grant, and Sioux counties) and northwestern South Dakota (Corson and northeastern Perkins counties). Farther east, a general 1-category improvement was made in southeastern North Dakota and northeastern South Dakota (see Midwest summary) where 2-5 inches fell. In contrast, less rain fell in northwestern South Dakota and extreme southwestern North Dakota (Bowman and Slope counties), and with reports of low yield and alfalfa harvests rivaling 1988, near-record June warmth, and poor VegDri values, some deterioration was made. D2 was extended northward into western Harding County, SD, and D1 was pushed northward into western Slope County, ND. In the central Plains, showers were more scattered in nature, with the few small D0 and D1 areas generally unchanged except for the removal of D0 in eastern Nebraska (see Midwest summary). In the southern Plains, scattered decent rainfall was limited to southwestern Texas, north of Midland, TX (Martin, Howard, Borden, and Dawson counties), and northeastward into central Oklahoma. Hot weather, however, overspread much of the southern Plains with temperatures averaging 6 to 9 degs F above normal and triple-digit highs. Where the rains missed and short-term (at 30- and 60-days) deficiencies have developed, small D0 areas were added in the Texas Panhandle, northeastern Texas, and south of Beeville, TX (Live Oak and San Patricio counties). Similarly in Oklahoma, D0 and D1 was expanded where the rains missed and short…

Northwest and Northern Rockies

After last week’s addition of D1 along the Oregon coast due to unseasonably dry and occasionally warm weather since April, this week brought unseasonably cool and wet weather to the entire region. In fact, it was cold enough for accumulating snow to fall in central Idaho north of McCall at an elevation of 6,000-7,000 feet. With precipitation amounts of 0.5-2 inches along the coast and in the northern Cascades and parts of the northern Rockies, it was almost enough to make improvements in parts of the region, however, since the past 3-4 months were quite dry and warm and some drought impacts had already commenced (e.g. northeastern Oregon), this event was not enough for any improvements west of the Rockies. In the northern Rockies and eastward, however, enough precipitation (2-3 inches) fell to remove D0 in northwestern Montana (Lake County) and 1.5-2 inches in northern Musselshell and northern Golden Valley Counties in central Montana. In eastern Idaho, D0 was reassessed, with the northern portion removed per 0.5 inches of precipitation and good water supplies while D0 was shifted southward into the headwaters of the Snake River where less precipitation fell and most indicators are showing moisture shortages. In northern Colorado (central Rockies), D0 was expanded into Larimer, Boulder, and Gilpin counties due to recent dryness, 6-month SPIs 0 to -1.5, and the VegDri showing some stressed vegetation. Western Boulder County saw a wild fire start last week aided by the hot, dry, and windy weather…

California and the Great Basin

The normally dry summer months in this region lived up to its billing as no precipitation fell across the entire area except for light amounts (0.1-0.5 inches) in far northern locales. Temperatures generally averaged below normal for the week, providing some relief for containment of new wild fires thanks to lower readings and higher humidity. As to be expected during the summertime, status-quo is most-likely for the next few months – unless the monsoon changes its trajectory – and even that may not be enough for any improvement depending on temperatures…

Southwest

After a promising start to the monsoon last week in the Four Corners states, shower activity abruptly stopped across most areas as dry and warm weather prevailed. In fact, weekly temperatures averaged 6-8 degs F above normal with triple-digit highs in eastern New Mexico and west Texas, but gradually decreased to subnormal readings in far western areas. Light, scattered rains (less than 0.5 inches) were confined to extreme southeastern Arizona and parts of New Mexico, with heavier amounts (0.5-2 inches) in southwestern Texas. The rains were enough near El Paso, TX, to remove a bit of the D0 there. Since the previous week was generally wet and short-term indices are actually near or above normal (wet) due to low late spring and early summer normal precipitation totals, no changes were made…

Looking Ahead

During the next 5 days (July 14-18), light to moderate precipitation (0.75-1.5 inches) is expected across much of the northern and central Plains, Midwest, Tennessee Valley, southern Appalachians, Carolinas, southern Louisiana and Florida, and the Northeast, with the largest totals (2-3.5 inches) in the south-central Plains, southern Appalachians, and North Carolina. Little or no rain is forecast for much of the Far West, Rockies, southern Plains, and coastal New England. Temperatures should average above normal in the Southwest and southern High Plains, Deep South, and in the Atlantic Coast States, with subnormal readings in the Northwest, northern Plains, and Midwest.

The NWS 6- to 10-day outlook for July 19-23 favors sub-median precipitation for much of the lower 48 States (West, northern Rockies, Plains, Midwest, southern Alaska), except for odds tilted toward above-median rainfall in northern Alaska, the Southwest, and small areas of the Pacific Northwest, southern Texas and Florida, and eastern Carolinas. The chances for above normal temperatures are high in southern Alaska and across much of the contiguous U.S., especially in the North Central States. Exceptions to this include eastern Alaska and the Pacific Northwest where subnormal readings are likely.

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