#Drought news: No change in depiction for #Colorado

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


Multiple cold fronts, associated with an amplified upper-level trough, resulted in heavy rainfall across the eastern third of the continental U.S. during the final week of September. A widespread area of 2 to 4 inches, locally to 10 inches, was observed from the Tennessee Valley northeast to southern New England. A strong subtropical ridge maintained below normal precipitation and above normal temperatures (6 to 8 degrees F) across the Coastal Plain of Georgia south to the Atlantic coastal areas of Florida during the past week. A pair of strong surface highs shifted south from Canada into the north-central U.S. where below-normal temperatures were observed at the end of September through the beginning of October. Hurricane Rosa, in the East Pacific, turned northeast and made landfall as a tropical depression in the northern Baja Peninsula at the beginning of October. Heavy rainfall associated with Rosa spread northward from northwestern Mexico and triggered flash flooding across southern Arizona during October 1-2…

High Plains

Light precipitation (0.5-1 inch) and 7-day temperatures averaging 5 to 10 degF below normal was enough to provide some improvements to the drought across the Dakotas as autumn is an ideal time of year for soil moisture recharge due to the lack of evaporation and minimal plant growth. Based upon a combination of various tools, the cool, wet weather warranted improvement in northwestern and southwestern ND and northeastern SD (D2 to D1), central SD (D1 to D0), and east-central and south-central ND, north-central and southwestern SD, and northeastern WY (D0 to nothing). Elsewhere, the light precipitation and subnormal temperatures were enough to keep conditions from deteriorating, but not wet enough for any improvement. Although it has been dry for the past 60-days in western Nebraska and northwestern Kansas, the cool weather delayed the introduction of D0 for now, but rain will be needed soon to prevent deterioration. In addition, as explained in the Midwest and South summaries, D0 was expanded into southeastern Kansas with respect to the large Midwestern drought area as 30-day deficits had accumulated there…


Remnant moisture and showers from former Hurricane Rosa in the East Pacific began to spread north into the desert Southwest by the end the valid period (12Z Oct. 2). South-central Arizona received 1-3 inches of rainfall, locally to 6 inches, which resulted in a 1 to 2 category improvement and included reports of flash flooding and a dam failure in western Pima County. Since more heavy rainfall with the remnants of Rosa occurred after 12Z Tuesday, additional improvements are anticipated across the Southwest next week. Onshore flow with a Pacific storm brought 0.5 to 2 inches of rainfall to coastal Washington and northwest Oregon where slight improvements were made as USGS 7-day stream flows rose to near-normal levels. Additionally, slight improvements were made in extreme east-central New Mexico due to changes in neighboring west Texas and recent rains (see South summary). However, further expansion of D3 was made in west-central Oregon (Deschutes, Crook, and Jefferson Counties) due to numerous months through September (out to 18-months) where the Standardized Precipitation Evapotranspiration Index (SPEI) was less than -1.5, along with corresponding drought impact reports that included surface water tributaries used for stock watering that dried up by early August, hay crops were reduced 50%, and remaining forage was of poor quality. Elsewhere, drought coverage and intensity remained unchanged throughout the remainder of the West…

Looking Ahead

During the next 5 days (October 4-8), a highly amplified upper-level pattern is likely to become established across the middle latitudes of the North Pacific and North America. A highly amplified upper-level trough are forecast to result in widespread above-normal precipitation throughout the Great Basin and north-central Rockies. The first major snowfall of the season is likely to blanket the Rocky Mountains with the higher elevations forecast to receive more than a foot. Accumulating snow, with locally high amounts, is probable for parts of the northern and central high Plains. As the upper-level trough amplifies over the West, maximum temperatures are forecast to average as much as 20 to 30 degrees F below normal across the north-central Rockies and adjacent high Plains on Oct 7 and 8. Multiple waves of low pressure are likely to emerge from the upper-level trough over the western U.S. and bring widespread heavy to excessive rainfall (3 to 7 inches, locally more) from the southern Great Plains northeast to the upper Mississippi Valley. The strong ridge aloft is likely to result in little to no rainfall along with much above-normal temperatures across the increasingly dry areas of Georgia.

For the CPC 6-10 day extended range outlook (October 9-13), indicates that the high amplitude pattern is likely to persist, resulting in a high confidence forecast with very high odds (above 80 percent)of below normal temperatures forecast for the northern Great Plains, northern/central Rockies, and Great Basin. Very high odds (above 80 percent) of above normal temperatures are forecast across the eastern third of the continental U.S. (CONUS). Above-normal precipitation is favored for much of the CONUS with the highest odds across the north-central Rockies, Great Plains, and middle to upper Mississippi Valley. Above-normal temperatures are likely throughout Alaska except for the Alaska Panhandle. Enhanced odds for above-normal precipitation are forecast for the Aleutians and mainland Alaska, while below-normal precipitation is favored to continue across the Alaska Panhandle.

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