This Week’s Drought Summary
A large shift in the weather pattern occurred this week across the lower 48 states. Early in the week, low pressure exited the Great Lakes region, allowing temperatures to gradually moderate during the latter half of the week across portions of the eastern contiguous U.S. (CONUS). In the western CONUS, high pressure broke down as a strong storm system moved into the Pacific Northwest heading into the weekend. As this storm system moved eastward into the Great Plains through the weekend and leading up to Tuesday, October 25, many locations across the western and central CONUS experienced above-normal precipitation, with cooler than normal temperatures in the system’s wake. However, with surface high pressure early in the week followed by southerly flow ahead of the storm system, warm temperatures dominated much of the central CONUS for the week as whole, with above-normal average temperatures also extending northeastward into the Great Lakes and Northeast. Unfortunately, given the expanse of drought and abnormal dryness across the U.S., antecedent dryness led to another week of degradations for many not receiving rainfall, even in areas where temperatures were cooler than normal this week. Warm conditions and high winds further exacerbated conditions in drier areas across the Great Plains. Fortunately, in areas seeing the heaviest rainfall amounts, particularly across the Southern Plains and Ozarks, some improvements were also warranted.
A storm system moving out of the Rockies and intensifying across the Southern Plains dropped in excess of 2 inches of rainfall in a large swath from northeastern Texas to the western Ozarks, warranting 1-category improvements across many of these locations. In surrounding areas that received heavier precipitation amounts, improvements were more targeted in nature, as amounts were not enough to eliminate 90-day deficits. Farther eastward, from the Lower Mississippi Valley to the Tennessee Valley, antecedent dryness and a drier than normal week resulted in another round of widespread 1-category degradations.