This week’s drought summary
An atmospheric river brought heavy rain and high-elevation snow across part of the West, leading to drought improvements in California, the Pacific Northwest, the northern Rockies and the Great Basin. A band of heavy rainfall, combined with severe weather, impacted the Southeast, leading to areas of drought improvement in Georgia. Meanwhile, persistent dryness led to the expansion of drought in the Carolinas. Drought in the High Plains remains largely unchanged; much of the excess moisture is tied up in snowpack and its effects on soil moisture and groundwater recharge remain to be seen. Drought expanded across parts of the South where short-term moisture deficits on top of longer-term drought continue to build.
Much of Oklahoma and Texas missed out on this week’s precipitation events, resulting in the expansion of drought. In Oklahoma, temperatures averaged 10 to 13 degrees above normal over the previous 2 weeks while precipitation has been less than 50% of normal over the past 4 months. Extreme (D3) drought expanded in response to well-below-normal (10th percentile or lower) measurements of streamflow, groundwater and soil moisture conditions. Texas also saw a swath of degradations from the north-central region to South Texas where short-term moisture deficits, on top of longer-term drought, have continued to build, and streamflow, soil moisture and groundwater levels range from below (10th to 24th percentile) to well below normal (10th percentile or lower). In the eastern part of the region, last week’s rainfall erased lingering areas of abnormal dryness.