October 2021 Climate Summary
Snow in Laramie WY, Photo courtesy Gavin Rush
First Snow for the High Plains
Snow made its first appearance for many portions of the region in October. Cooler fall temperatures and above-normal precipitation in Wyoming, The Dakotas, and the higher elevations in Colorado contributed to the appearance of the season’s first significant snowfall.
Southeastern Wyoming had its first Winter Storm and High Wind event of the season. High winds of 40 to 50 mph (64 to 80 km/h) coupled with snowfall led to the first Blizzard warnings being issued this season for counties in southeastern Wyoming. Highway closures, due to the blizzard, resulted in major travel issues. Travel alerts did not appear on some phones, so motorists were not aware of the closures and were stranded in towns along the interstate. Some motorists had to sleep in their cars as limited hotels in small towns were full and they could not get to other areas with the road closures. While this storm created major travel headaches, it did bring much-needed relief to neighboring wildfires, as well as the hot temperatures from summer, while also helping to improve air quality in the region. The Colorado Rockies also received their first notable snowfall of the season. Multiple snow storms impacted the region in October bringing over a foot of snow in different areas. Winter Storm Warnings were issued for the higher elevations and stretched north to south across the entire range in Colorado. After a storm that brought 14 inches (356 mm) of snow to the southwest part of the state, Wolf Creek ski area near Pagosa Springs became the first in Colorado to open for the season. This was quickly followed by multiple other resorts releasing their opening dates bringing an early start to the ski season.
After a summer filled with extreme heat and drought, many areas welcomed the relief of colder temperatures and snow. While drought is still present in the High Plains, this above-normal precipitation and snow did help to provide minor improvement across Wyoming, The Dakotas, and areas in Colorado.
Above: Departure from 1991-2020 normal temperature (left) and percent of normal precipitation (right) for October 2021 in the High Plains region.
Maps produced by the High Plains Regional Climate Center and are available at: http://hprcc.unl.edu/maps/current
Precipitation for October varied across the region. Above-normal precipitation was observed across Wyoming and stretched into the Dakotas. The largest departures from normal occurred in the Dakotas, eastern Nebraska, and eastern Kansas with totals as much as 4.5 inches (114 mm) above normal. This large area of above-normal precipitation led to many locations ranking in the top 10 wettest on record for October, many were in the Dakotas (see page 6 for monthly rankings). Huron, SD observed 5.22 inches (133 mm) for the month which ranked as the 3rd wettest October on record, with the record of 6.44 inches (164 mm) being set in 1946. This was 268 percent above the normal precipitation for October. The wetness during the month of October brought both snowstorms and tornadoes to South Dakota. To the west, in Rapid City, blowing snow due to high winds created low visibility, which resulted in highway closures for the duration of the storm. As the storm progressed, several tornadoes were reported in the northeastern corner of the state.
Areas in Wyoming also observed above-normal precipitation for October. Casper, WY recorded 2.69 inches (68 mm) of precipitation which ranked as the 4th wettest October on record, the record being 4.62 inches (117 mm) set in 1998. This precipitation was 226 percent above normal for Casper. Lander, WY, which observed 255 percent of its normal precipitation for October, reported their 9th wettest October on record with 3.57 inches (91 mm) of precipitation.
Despite the wetness in the northern and eastern parts of the High Plains, dryness was present in a large portion of the region. Eastern Colorado and the western parts of Kansas and Nebraska experienced below-normal precipitation for the month, with large swathes of 50 percent or below-normal precipitation. Denver, CO recorded the 8th driest October, with only 0.08 inches (2 mm) of precipitation. The dryness within this area has impacted agriculture. According to the USDA’s Weekly Weather and Crop Bulletin, pasture and rangelands that were rated as poor to very poor conditions were covering above 25 percent of the area for Colorado, Kansas, and Nebraska. Corn harvest was also ahead of the 5-year average for all states in the High Plains.
Above: Total precipitation in inches (left) and departure from normal
precipitation in inches (right) for October 2021. These maps are
produced by HPRCC and can be found on the Current Climate Summary Maps page at: http://hprcc.unl.edu/maps/current
Above-normal precipitation during the month of October led to improvements in streamflow across parts of the region. Over large parts of North Dakota and Wyoming, streamflow returned to normal or above normal state. Colorado also observed improvements in conditions, however, pockets of much below normal streamflow are still present. The Southeastern portion of the Missouri River Basin continued to remain above normal for October with some streamflow observations much above normal. In contrast, streamflow in the tri-state corner of Colorado, Nebraska, and Kansas remained much below normal after another dry month for this region, with several gauges observing record low flows.
Temperatures for October remained above normal for most of the High Plains. The temperature departure gradient stretched northeast with the southwestern portion of the region observing temperatures below-normal and the northeastern portion observing the greatest departure of above-normal temperatures. The Rockies, in western Colorado, observed temperatures 2 to 4 degrees F (1.1 to 2.2 degrees C) below normal, while the Dakotas observed the highest departure from normal with temperatures 4 to 8 degrees F (2.2 to 4.5 degrees C) above normal.
As a result of these above-normal temperatures in the Dakotas, a few locations ranked in the top 10 warmest October on record (see page 6 for October rankings). Dickinson, ND observed its 5th warmest October on record with an average temperature of 49.1 degrees F (9.5 degrees C). Grand Forks, ND tied a record set in 1900 with its 10th warmest October on record with an average temperature of 49.4 degrees F (9.7 degrees C). While October 2021 only ranked as the 10th warmest for Grand Forks, this was a departure of 6.2 degrees F (3.5 degrees C) above normal. Above normal temperatures in North Dakota provided challenges to some deer hunters. Lower temperatures are ideal for deer hunting because it increases deer activity as they look for more food to store energy and keep their bodies warm. Without these cooler temperatures, the deer are remaining in the brush longer and are less likely to come out during the middle of the day making it harder for deer hunters in the region.
Below normal temperatures and above-normal precipitation in the Rockies, contributed to the season’s first significant snowfall. Multiple storms provided a fresh layer of snow to the mountain range. Ski resorts in Colorado are opening, which is welcomed as it will help boost the local economy and provide jobs after a hard season in 2020.
Beneficial precipitation across drought-stricken areas of the High Plains led to improvements in drought and abnormally dry (D0-D4) conditions. The most notable improvements included a reduction of 12 percent in extreme and exceptional (D3-D4) conditions. Despite the improvements this month, 83 percent of the region is still experiencing D0-D4 conditions.
Conditions improved significantly in North Dakota after much of the state experienced above-normal precipitation during October. D3-D4 conditions were reduced 50 percent during the month, with only 9 percent of the state currently under the most severe drought conditions. In South Dakota, similar improvements occurred. D3-D4 categories were removed for the state while severe to exceptional (D2-D4) drought was reduced by 27 percent. Wyoming also experienced a 16 percent decrease to D3-D4 conditions. Despite the improvements this month, Colorado saw an increase of 21 percent to drought conditions (D1-D4). Throughout the rest of the region, other minor improvements were observed. According to the U.S. Monthly Drought Outlook for November, drought development is likely in southern Colorado and western Kansas.
The U.S. Drought Monitor is produced as a joint effort of the U.S.
Department of Agriculture (USDA), National Drought Mitigation
Center, U.S. Department of Commerce, and the National Oceanic and
Atmospheric Administration (NOAA). For current Drought Monitor
information, please see: http://droughtmonitor.unl.edu/
According to the Climate Prediction Center, La Niña conditions have developed during the month of October. A La Niña Advisory has been issued and La Niña conditions are expected to continue throughout the winter season. For more information, visit https://www.cpc.ncep.noaa.gov/products/analysis_monitoring/lanina/enso_evolution-status-fcsts-web.pdf
The National Weather Service’s long-range flood outlook through January indicates a continual decrease in the chance of minor flooding. There is a greater than 50 percent chance of minor flooding in the lower Missouri River Basin in November and that will continue to decrease through January where it becomes a less than 20 percent chance. According to the National Interagency Fire Center (NIFC), significant wildland fire potential has returned to normal for the High Plains and is expected to continue to remain normal through January.
The seasonal temperature and precipitation outlooks below combine the effects of long-term trends, soil moisture, and when applicable, the El Niño Southern Oscillation cycle (ENSO). To learn more about these outlooks, please visit http://www.cpc.ncep.noaa.gov.
The three-month temperature outlook shows an increased chance for above-normal temperatures for most of the contiguous United States. The highest chances for above-normal temperatures can be observed in the Southwestern portion of the country. In the Southern High Plains, there is an increased chance of above-normal temperatures during the next three months, whereas in the majority of the Northern High Plains there are equal chances of above-, below-, and near-normal temperatures.
The precipitation outlook for the next three months indicates below-normal precipitation across the southern half of the United States, whereas above-normal precipitation can be observed throughout the Northwest and Northeast. In most of the High Plains region, there are equal chances of above-, below-, and near-normal precipitation. A portion of Northwestern Wyoming has a slightly increased chance of above-normal precipitation, while a small area of southern Kansas and Colorado has a slightly increased chance of below-normal precipitation.
The U.S Seasonal Drought Outlook released on October 21st indicates drought conditions are expected to persist across the Western U.S and High Plans over the next three months. Drought conditions are expected to show minor improvements in the Northwest, with some areas likely to observe drought removal. It is also likely that in portions of Colorado, Florida, the Carolinas, and the Southern Plains, drought conditions will develop.
Above: The three-month temperature probability outlook (top), the
three-month precipitation probability outlook (middle), and the U.S.
Seasonal Drought Outlook (bottom). For more information on these
outlooks, produced by the Climate Prediction Center, see:
Station Summaries: By the Numbers
Download PDF version below.