Map released: Oct. 29, 2020 | Data valid: Oct. 27, 2020
This week’s drought summary: A blast of frigid Arctic air invaded the North Central States, producing weekly temperatures averaging 15 to 25 degrees F below normal in Montana, the Dakotas, Wyoming, Minnesota, Iowa, and Nebraska. The chill was accompanied by a slow-moving storm system that produced light snow across most of the Rockies, Plains, and upper Midwest. Although outdoor conditions were harsh, the storm and cold were welcome as it brought a halt to the abnormal warmth and dryness that had expanded and deepened the drought in the region. In the southern Plains, mixed precipitation (snow, sleet, freezing rain, and rain) glazed portions of New Mexico, Wes Texas, Oklahoma, and Kansas, while beneficial moderate to heavy rains fell from southwestern Oklahoma northeastward into the eastern Great Lakes region.
Heavy rains also were measured in the western Great Lakes region and south Florida. Scattered, light precipitation was measured across most of the Pacific Northwest, Southeast, Midwest, and western portions of the Northeast. Much of the Southwest and Intermountain West was dry, with wildfires still burning across California. In addition, little or no precipitation fell on the Southern Plains, parts of the Southeast, and eastern sections of the Northeast. Above normal temperatures enveloped the Southwest, Southern Plains, and eastern third of the Nation. At the end of the period, all eyes were on Hurricane Zeta in the Gulf of Mexico as it tracked toward yet another Louisiana landfall.
South: A stalled front and the winter storm in the Southern Rockies brought beneficial precipitation to portions of the South-Central Plains and lower Missouri Valley. With temperatures dropping as the week progressed, light frozen precipitation (freezing rain, sleet, snow) coated parts of western Texas and Oklahoma and southern Kansas, with heavier rains (1.5-4 inches, locally higher) reported from southwestern Oklahoma northeastward into Missouri. Unfortunately, southern and eastern sections of Texas missed out on the rain, and short-term dryness (2-3 months) increased, with an expansion of D0 and D1 in southern and eastern sections, and D2 in south-Central Texas. With the ongoing storm in the southern Rockies on day seven and more precipitation expected, a wait and see approach was made, thus it was status-quo for West Texas and Oklahoma this week.
In contrast, welcome rains fell from extreme North Texas across Central Oklahoma and into northwestern Arkansas, providing a one-category improvement to most areas, and even some small two-category improvements in northwestern Arkansas and southwestern Missouri where the rains were the greatest (3.5-5 inches). Elsewhere, the small D0 in southeastern Louisiana was expanded northeastward as the past two to three months have brought 25-50% of normal rainfall, creating four-to eight-inch deficits. However, Hurricane Zeta is expected to inundate this area as it makes landfall near here, so the D0 should be a memory next week.
Looking ahead: During the next five days (Oct. 29-Nov. 2), WPC’s QPF precipitation focuses on Hurricane Zeta and the southern Rockies upper-air low as they both track northeastward. Heavy rains and strong winds are expected at Zeta’s landfall in eastern Louisiana, then as it weakens, moisture from Zeta will become entrained into the upper-air low, with a band of heavy precipitation (one to four inches) expected from the South-Central Plains northeastward into the mid-Atlantic, and in the Southern and Central Appalachians. Little or no precipitation is forecast elsewhere across the contiguous U.S., except for some lighter amounts in western Washington, the western Great Lakes region, and Florida. Temperatures will average near to below-normal in the eastern half of the Nation, but above-normal in the West, especially in the Great Basin.
The Climate Prediction Center’s six to ten day outlook (Nov. 3-7) favors below-normal precipitation across the eastern half of the U.S. and along the southern coast of Alaska, with odds for above-normal precipitation in the Northwest and Northern Alaska. Temperatures are anticipated to be above-normal in the West, Plains, upper Midwest, and western Alaska, near-normal in the Southeast and mid-Atlantic, and subnormal in New England and southern and eastern Alaska.