The trend of the past few weeks toward generally increased precipitation across the Contiguous 48 states continued this week, with several sizeable swaths of heavy precipitation recorded, and broad coverage of near or above normal amounts.
Several other large areas recorded at least an inch and locally up to 5 inches, including most of the northern Intermountain West, a swath from the southern High Plains through the central Great Plains and the middle and upper Mississippi Valley. Numerous locations in the Lower Mississippi Valley and northwestern Alabama reported 3 to 5 inches of rain, as did a swath in north-central Kentucky and isolated spots in western Tennessee, northwestern Texas, eastern Oklahoma, southwestern Kansas, and western Iowa.
The broad coverage of moderate to heavy precipitation prompted sizeable areas of improvement in this week’s Drought Monitor.
Little or no precipitation was also recorded across the southern reaches of southern Texas, most of the central and northern Plains, and the southwestern quarter of the country, with patches of deterioration noted in these areas as well this week.
The U.S. Drought Monitor is jointly produced by the National Drought Mitigation Center at the University of Nebraska-Lincoln, the U.S. Department of Agriculture and the National Oceanic Atmospheric Administration. (Map courtesy of NDMC.)
South
The South Region experienced highly variable rainfall although more areas experienced significant rainfall and improved conditions than dryness and deterioration. The latter was confined to central and southern Texas where little or no rain fell, expanding D0 through much of Deep South Texas and prompting the introduction of D1 in a patch near the lower Rio Grande River.
Farther north, moderate to heavy precipitation prevailed, especially across western Texas, much of Oklahoma, portions of Louisiana, Mississippi, and western Tennessee. A large part of these areas saw a 1-category improvement, nearly eliminating severe drought (D2) in western Arkansas, eastern Oklahoma, and adjacent Texas, and also decreasing D1 coverage substantially across the northern and eastern tiers of the Region.
Midwest
Moderate to heavy rain also fell in central and southern Minnesota, the western half of Iowa, and the western tier of Missouri. Amounts exceeded an inch through almost all of these areas, with 2 to 3 inches soaking a few areas.
As a result, there were sizeable areas with improvement across central and southern sections of Minnesota, and along the western tier of the Midwest region.
High Plains
Moderate to heavy precipitation was widespread across the southern and eastern reaches of the High Plains Region, and moderate amounts were observed in some of the higher elevations of Wyoming and central Colorado, and over northern North Dakota. Elsewhere, only a few tenths of an inch, at most, was measured.
In the areas of heaviest precipitation (1.5 to approaching 3 inches), improvement was introduced. This included significant parts of Kansas, southeastern Colorado, eastern sections of Nebraska and South Dakota, and a relatively small area in southeastern North Dakota. The remainder of the region, under a regime of light to moderate precipitation at best, dryness and drought assessments were unchanged.
West
Areas of improvement were introduced where there was spottier moderate to heavy rain in parts of the westernmost Montana. Moderate to heavy precipitation (locally up to 3 inches) also doused southeastern New Mexico adjacent to the heavy rains in western Texas, with similar 1-category improvements introduced in areas with over 1.5 inches of precipitation.
Elsewhere, only scattered light precipitation was reported, and dryness and drought were primarily unchanged. Some deterioration was noted in west-central Montana (to D1) while a significant swath of eastern Montana slid into extreme drought (D3).
Looking ahead
During the next five days, Nov. 21 to 25, moderate to heavy precipitation is expected in the western and northeastern quarters of the contiguous states, and along the immediate Canadian border. Lesser amounts, if any, are expected in and around the Plains and along most of the southern tier.
In contrast, little or no precipitation is expected in the Plains from the central Dakotas southward, and along the southern tier of the country from southeastern California eastward through Georgia and most of the Carolinas.
Very warm weather is expected in central and southern Texas, with temperatures expected to average 10 to 13 degrees Fahrenheit above normal.
Meanwhile, unusually low temperatures averaging 10 to 17 degrees below normal are anticipated from the central and western Dakotas through most of Montana. Temperatures may average up to 10 degrees above normal from the Upper Mississippi Valley and central Plains westward through the Great Basin and northern Intermountain West. Near or slightly above normal temperatures are expected elsewhere.
The Climate Prediction Center’s 6- to 10-day outlook (valid Nov. 26 to 30) favors above-normal precipitation in a swath from the Southwest and the Great Basin eastward through most of the Plains. Only central and southern Texas are outside the area where above-normal precipitation is expected. Odds exceed 50% over the east-central Rockies and adjacent High Plains. Unusually dry weather is more likely in western Texas and parts of the Intermountain West, plus central and northern portions of the Rockies and Plains.
Cold weather is favored across central and northern portions of the Rockies and the Plains. Chances for significantly subnormal temperatures are 70 to 80+ percent from Montana east of the Rockies and most of the Dakotas.
Richard Tinker is with the National Oceanic Atmospheric Administration, National Weather Service, National Centers for Environmental Prediction, and Climate Prediction Center.
