This week’s drought summary
This U.S. Drought Monitor (USDM) week saw widespread improvements across areas of the Midwest and eastern portions of the Central and Northern Plains states in response to beneficial rainfall. Rainfall accumulation in these areas ranged from 2 to 12+ inches leading to one-category improvements across areas of the Dakotas, Nebraska, Kansas, Iowa, Minnesota, and Wisconsin. In the South, Hurricane Ida made landfall along the Gulf Coast of Louisiana on Sunday as a Category 4 hurricane with maximum sustained winds of 150 mph. The hurricane caused extensive infrastructure damage including widespread power outages in Louisiana and Mississippi, impacting more than 1 million homes and businesses as well as stranding residents amongst the floodwaters. In the West, dry conditions persisted across most of the region with approximately 90% of the region currently categorized as “in drought”. In California, two major wildfires (Dixie and Caldor fires) continued to intensify and expand due to the dry and windy conditions. In El Dorado County, California, the Caldor Fire continued to rapidly spread this week leading to the evacuation of residents in communities on the southern end of the Lake Tahoe Basin—including the City of South Lake Tahoe. In addition to impacting fire conditions, the on-going drought in California continues to strain the state’s water resources. This is reflected in the reservoir levels of California’s two largest reservoirs, Lake Shasta and Lake Oroville, which are currently at 43% and 34% of historical averages, respectively. In the Southwest, Lake Powell is currently 31% full and Lake Mead is 35% full. The total Lower Colorado system is at 40% full, according to the U.S. Bureau of Reclamation, compared to 50% full at the same time last year.
South
On Sunday, Hurricane Ida made landfall along the Louisiana coast as a Category 4 hurricane with maximum sustained wind of 150 mph. Hurricane Ida was the second most intense hurricane to impact the state of Louisiana, causing major widespread damage to infrastructure across the southeastern part of the state. Rainfall accumulations in the direct path of Ida ranged from 2 to 15+ inches with the heaviest accumulations observed along the coastal areas of southeastern Louisiana and Mississippi. On this week’s map, drought-related conditions deteriorated in north-central as well as in the Oklahoma Panhandle where short-term dryness (past 30-day period) and reports of poor crop conditions led to the introduction of an area of Moderate Drought (D1). In the Texas Panhandle, precipitation deficits during the past 30- to-90-day period led to expansion of areas of Abnormally Dry (D0), while conditions improved to the south in the Big Bend region where precipitation has been above normal during the past month. According to NOAA NCEI, the May-July 2021 period was the 4th wettest on record in the South Climate Region and the 3rd and 5th wettest May-July period statewide for Texas and Louisiana, respectively.