Drought Monitor Report Shows La Niña Winter Effects are Already PresentThu, 02 Dec 2021 12:39:58 CST
According to the latest U.S. Drought Monitor report, several Pacific weather systems moved across the contiguous U.S. during the past week, bringing cold fronts that stretched the width of the country and triggered precipitation in some areas. As a result, the past week was wetter than normal in parts of the Pacific Northwest, northern Rocky Mountains, Great Lakes and Texas. Otherwise, the weather was drier than normal, with large parts of the West and Great Plains receiving no precipitation.
With data ranging from Nov. 24 to Nov. 30, 2021, the persistent above-normal temperatures contributed to excessive evapotranspiration in western portions of the Great Plains and parts of the West, as seen in Evaporative Demand Drought Index and Evaporative Stress Index indicators. Lack of precipitation, excessive evapotranspiration, and windy conditions further dried soils especially in the western portions of the Plains, as seen in several soil moisture indicators. Drought indicators such as the Standardized Precipitation Index and Standardized Precipitation Evapotranspiration Index, reflected the mounting precipitation deficits. The continued dryness expanded or intensified drought in parts of the southern to central Rocky Mountains, Great Plains and Southeast.
In the Southern Plains, moderate-to-severe drought conditions decreased in a few parts of Texas where the heaviest rains fell, but more of the state and much of Oklahoma saw an expansion of abnormal dryness and moderate-to-severe drought. With every passing day of no precipitation, low humidity and high evapotranspiration, the wildfire threat continues to grow in Texas and Oklahoma. Nov. 28 USDA reports had 64% of the topsoil moisture in Texas was dry to very dry and 45% of the winter wheat crop was in poor to very poor condition. In Oklahoma, the statistics were 59% dry to very dry for topsoil moisture and 16% for winter wheat condition.
The High Plains saw little to no precipitation this past week. Reassessment of the last 2 months’ precipitation led to a contraction of moderate drought in northeast North Dakota and severe drought in the central part of the state. At the same time, water levels in ponds and dugouts remained low despite late-summer to early-fall rains, prompting expansion of severe drought in other parts of central North Dakota. Above-average temperatures and no precipitation for the last 2 weeks resulted in an expansion of moderate drought in southern parts of North Dakota and adjacent South Dakota. In Wyoming, many basins had below to well-below-normal snowpack with no snow across the High Plains portion of the state. Snow, where it fell, was confined to the highest peaks (above 8500 ft). The snow conditions combined with excessive evapotranspiration, drying soils, short-term dryness and longer-term dryness prompted an expansion of moderate-to-extreme drought in parts of Wyoming. In Colorado, drying soils, high evapotranspiration, low-mountain snowpack and mounting precipitation deficits resulted in an expansion of moderate-to-extreme drought in many parts of the state. Nov. 28 USDA statistics had 84% of Colorado’s topsoil dry to very dry and 33% of the winter wheat in poor to very poor condition. Abnormal dryness and moderate drought expanded in southern and western parts of Kansas also.
In the West, the coastal regions of Oregon and Washington saw healthy amounts of precipitation. 0.5 to 2 inches fell in parts of the northern Rocky Mountains and in a few parts of the southern Rocky Mountains. Otherwise, much of the West was dry. Drying soils and mounting 3-month-precipitation deficits prompted an expansion of moderate to extreme drought in parts of New Mexico. Nov. 28 USDA reports had 81% of New Mexico’s topsoil short or very short of moisture. Otherwise, no change occurred to the vast areas of moderate to exceptional drought which covers the West.
To view the Contiguous U.S. Drought Map, click here.
Looking ahead to Dec. 7, a northern weather system is expected to affect much of the West with Pacific frontal systems following. Precipitation is expected to fall in the northern Rocky Mountains and eastern Oklahoma. Most of the Great Plains and Southwest are expected to get little to no precipitation.
From Dec. 7 to Dec. 11, 2021, above-normal precipitation is forecast across much of the West and northern High Plains and Midwest. Normal precipitation is expected for Kansas, Oklahoma and Texas. Above-normal temperatures continue to be likely for the western U.S. At the same time, temperatures for the bottom ¾ of the contiguous U.S. are expected to be higher than normal.
To view the 6 - 10 Day Precipitation Outlook, click here.
To view the 6 - 10 Day Temperature Outlook, click here.
According to the Monthly Drought Outlook map, drought condition improvement is likely for much of the Pacific Northwest, moving inland to western Montana. In the remainder of the West and Great Plains, drought is expected to persist or further develop.
To view the Monthly Drought Outlook map, click here.
According to data as of Nov. 24 to Nov. 30, 2021, drought conditions in Oklahoma have deteriorated. The largest change was in moderate drought conditions, which increased 19% since last week’s Drought Monitor report, to 60.71%. Extreme drought conditions did not change, steady at 2.2%. Severe drought conditions increased 3.5% to 15.9%. Overall, 86.6% of the state is experiencing abnormally dry conditions or worse, according to the report.
Cimarron County continues to experience the worst of drought conditions. Extreme drought conditions are also reported in Beaver, Harper and Woods counties. Severe drought conditions remain in the Panhandle, northwest and southwest areas in the state and the Tulsa area.
The 6-to-10-day precipitation outlook map shows Oklahoma is likely to receive normal precipitation levels. The 6-to-10-day temperature outlook map shows Oklahomans can expect higher-than-normal temperatures also.
While conditions remain dry in Oklahoma, wildfire danger looms.
To view the Oklahoma drought map, click here.
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