KIMBALL, Neb. – If the weather forecast proves to be correct, by the time you read this the warmth of late autumn will have been replaced by cold and snow. In a slightly ironic twist, the wintry conditions are expected to arrive within hours of the beginning of celestial winter.
A weather front featuring Arctic air and widespread snow was expected to move into the region late on Wednesday. Temperatures were expected to plummet into the teens and single digits and rain-changing-to-snow was expected to begin at about 11 p.m.
While precipitation from the weather front was expected to be widespread, it was also expected to be rather light. The forecast anticipated icy roads and periods of blowing snow, but did not forecast snowfall quantities.
Following on the heels of above average late-autumn warmth, the forecast cold snap could be quite hard on fall-seeded winter wheat. Much of the September-planted 2018 crop has continued to actively transpire and photosynthesize rather than enter winter dormancy. Actively growing wheat plants are highly susceptible to cold injury, and the sudden onset of frigid temperatures could take a heavy toll on next year’s crop.

Regional Forecast and Conditions
As of Tuesday morning (Dec. 19), the temperature at sunrise was 35 degrees under clear skies. There was a northeasterly breeze at 14 mph, gusting to 17 mph. The day was expected to remain clear with modest winds and with temperatures climbing into the mid-40’s.
A cold snap with attendant wintry weather was expected to flow into the tri-state region late on Wednesday. The forecast through the weekend calls for sharply colder air temperatures, a chance of widespread snowfall on Saturday, and some breeziness. Daytime highs are expected to climb only into the mid-teens. Overnight lows are expected to fall into the single digits and perhaps to below zero.
Little change is anticipated for Christmas Day through Wednesday. Conditions are expected to remain cold and clear and occasionally breezy. There is little chance of precipitation in the forecast during this period.
Daytime air temperatures warmed across the region last week. At Kimball the Dec. 12-18 daytime high averaged 49.71, about 4 degrees warmer than the previous week. The weekly high temperature was 65 degrees on Dec. 12. Overnight lows warmed as well, averaging 21.57 degrees, about 2.5 degrees warmer than the previous week. The weekly low temperature was 15 degrees on Dec. 14. The weekly mean temperature was 35.64 degrees, about 3 degrees warmer than the previous week, and about 7 degrees warmer than the Dec. average of 28.4 degrees. The long term average high and low temperatures at Kimball for Dec. are 41.7 and 15.0 degrees, respectively.
For the second week in a row, widespread but very light snow showers did little to provide moisture across the region. All 13 Panhandle stations reported a trace of snow but zero liquid equivalent precipitation during the Dec. 12-18 period. Liquid equivalent precipitation averaged 0.0 inches for the Panhandle, while snowfall averaged 0.01 inches.
With the exception of Gordon, which cooled slightly, soil temperatures warmed 1.7-2.8 degrees across the Panhandle over the Dec. 12-18 period: (this week/last week/change): Alliance 37.3/34.5 (+2.8) degrees; Gordon 32.7/34.4 (-1.7) degrees; Mitchell 37.0/36.2 (+0.8) degrees; Scottsbluff 35.2/34.5 (+0.7); and Sidney 35.8/33.7 (+2.1) degrees.
Winds near Kimball averaged northwesterly and occasionally quite breezy over the Dec. 12-18 period. Gusts for the week averaged 32 mph. High gust for the week was 48 mph on Dec. 14.

Dec. 22 Weather Almanac
Here’s an overview of Dec. 22 temperature and precipitation highs, lows, and averages over the preceding 123 years at Kimball. Data is taken from the High Plains Regional Climate Center (www.hprcc.unl.edu), where you can easily find and track data for your own particular location.
Last year (Dec. 22, 2016): Daily high temperature 37 degrees, overnight low 17 degrees, average temperature 27 degrees. Precipitation 0.00 inches, snowfall zero inches, snow depth zero inches.
The warmest Dec. 22 on record was 66 degrees in 1933. The coolest Dec. 22 high temperature was -13 degrees in 1990. The coldest Dec. 22 overnight low was -35 degrees in 1989. The warmest Dec. 22 overnight low was 43 degrees in 1964. Over the years since 1893 the high temperature on Dec. 22 has averaged 39 degrees, the overnight low 13 degrees, the daily average 25.7 degrees, precipitation has averaged 0.02 inches, snowfall 0.2 inches, snow depth zero inches.

The highest Dec. 22 precipitation total was 0.50 inches liquid equivalent in 1921. The greatest snowfall was 5.0 inches in 1921. Greatest snow depth was 7.0 inches in 1998.
Snow has fallen on Dec. 22 at Kimball 24 times over the last 123 years, with quantities ranging from a trace to 5 inches.

U.S. Drought Monitor
High Plains: Most of the region had above-average temperatures and little to no rainfall. The lack of precipitation continues a pattern of dryness in the region over at least the past couple of months.
Lincoln, Neb., has received only 0.08 inch of precipitation since Oct. 15, its driest such period on record.
Abnormally dry conditions (D0) expanded greatly over Colorado into western Kansas, and northeastward into Nebraska.
Moderate drought (D1) deteriorated to extreme drought (D2) in south central Kansas, adjoining the already extreme drought condition in north central Oklahoma.
Abnormally dry conditions were expanded across the remainder of southeastern Kansas. Moisture there is less than half of average. Soil moisture levels are down and surface water supplies (stock ponds) are shrinking.

West: During the last week In November, California’s South Coast climate division reported its second and third highest monthly minimum and average temperatures, respectively, and an average of just 0.10 inch of rainfall, compared to the 20-year average of average of 1.51 inches. Warmth and dryness continued into early December. Fueled by these conditions, and Santa Ana winds gusting to 80 mph, resulted in numerous Red Flag Warnings. These drought and weather conditions were also a contributing factor in the explosive growth of the fires that started in Southern California the first week of December.
Inland, along the southeastern California/Nevada border region, abnormally dry conditions (D0) were extended northwestward into southern Inyo County, Calif.,  and most of southern and central Nye County, Nev. It has been be extremely dry across the Mojave Desert this fall.
For the first time since records began in 1937, Las Vegas reported no measurable rainfall in October and November, and was on its eighty-ninth consecutive day without rain as of the writing of this report. Several other areas were also reporting no rainfall for at least two months.
In Utah, the continuing dry conditions warranted degrading the remaining abnormally dry conditions in the southeastern portion of the state to moderate drought (D1).
In New Mexico, the lack of precipitation over the past two months has taken a toll on soil moisture at 2-8 inch depths at most monitoring sites. Abnormally dry conditions spread across most of the eastern part of the state, save a small area in the southeastern corner.

National Summary: Conditions were dry and windy across much of the western United States over this past drought week.
Wildfires, fueled by strong Santa Ana winds, destroyed hundreds of structures and burned more than 100,000 acres, enhancing the state’s deadliest and costliest wildfire year on record. An unprecedented purple flag (wind) warning was posted on Dec. 8. Red flag warnings were posted from Colorado to Illinois on Dec. 11. Daily temperatures were above average across the western two-thirds of the U.S., particularly notable across the Southwest stretching into the High Plains.
Snow fell across the South and Southeast, a rarity in many places, including southern Texas eastward into Georgia. The storm unexpectedly dumped more than a foot of snow in parts of northern Georgia and North Carolina, with at least several inches widely reported. The storm continued to track across the mid-Atlantic and Northeast, leaving several inches on the ground there as well. Temperatures were as much as 15-25 degrees below average from parts of the Southern Plains to the Gulf Coast.
Overall, with respect to drought, continued lack of moisture led to more degradation across parts of the West, High Plains, Midwest, and the South. A few areas improved, mainly in some of the far southern areas, where plentiful precipitation fell this past week.
For more information on the U.S. Drought Monitor visit: http://droughtmonitor.unl.edu

U.S. Conditions and Weather Report
Cold air settled across the Great Lakes and Northeastern states, accompanied by snow showers and squalls. Snow was particularly heavy downwind of the Great Lakes.
Most of the remainder of the country experienced dry weather, although periods of precipitation affected areas from the Pacific Northwest to the northern and central Rockies.
Late in the week, beneficial rain developed across the western Gulf Coast region and spread into the lower Mississippi Valley, helping to revive pastures, winter wheat, and cover crops.
Extremely dry conditions persisted in several areas, including nearly all of the nation’s southwestern quadrant. In particular, mild, dry, breezy weather on the central and southern High Plains maintained stress on winter wheat, while similar conditions in southern California hampered wildfire containment efforts.
Similar to the previous week, cold weather across the eastern U.S. contrasted with mild conditions on the Plains. Weekly temperatures were as much as 10 degrees below normal in the lower Great Lakes region and southern Florida, but averaged 10 to 20 degrees above normal across the northern Plains.
Meanwhile, a high-pressure system parked over the northern Intermountain region contributed to cool, foggy conditions in many Northwestern valleys and warm, breezy weather in southern California and the Desert Southwest. As a result, temperatures averaged at least 5 degrees below normal across the interior Northwest, but averaged as much as 10 degrees above normal in coastal southern California.

USDA Weekly Weather and Crop Reports

Colorado, Nebraska and Wyoming

Weekly crop progress reports have ended for the growing season. Monthly reports will be issued during the first week of January, February, and March. Next year’s weekly reports will begin the first week of April 2018.