 Composite of tornado warnings and confirmed tornadoes on December 15–16, 2021 | |
| Type | Extratropical cyclone Winter storm Derecho Tornado outbreak |
|---|---|
| Formed | December 13, 2021 |
| Dissipated | December 18, 2021 |
| Highest gust | 100 mph (160 km/h) near Russell, Kansas (Derecho);[1] 112 mph (180 km/h) at Red Mountain Pass, Colorado (non-thunderstorm) |
| Lowest pressure | 967 mbar (28.6 inHg)[2] |
| Highest temperature | 76 °F (24 °C) in Oskaloosa Municipal Airport, IA[3] |
| Tornadoes confirmed | 120 (Record for a tornado outbreak in December) |
| Max. rating1 | EF2 tornado |
| Duration of tornado outbreak2 | 7 hours, 56 minutes |
| Maximum snowfall or ice accretion | 60 in (1,500 mm) east of Pinecrest, California[1] |
| Maximum rainfall | 8.74 in (222 mm) on Mount Tamalpais[1] |
| Fatalities | 5 direct, 2 indirect[note 1] |
| Damage | $1.8 billion (2021 USD)[4] |
| Power outages | >600,000 |
| Areas affected | Western United States, Midwestern United States, Canada |
Part of the 2021–22 North American winter and Tornadoes of 2021 1Most severe tornado damage; see Fujita scale 2Time from first tornado to last tornado | |
On December 15, a rapidly-deepening low-pressure area contributed to a historic expanse of inclement weather across the Great Plains and Midwestern United States, resulting in an unprecedented[5] December derecho and tornado outbreak across portions of the Northern United States, a region normally affected by snow and cold weather during this time of year. Non-thunderstorm winds spurred the formation of rapidly-moving fires across Colorado and western Kansas, with attendant dust and debris spreading eastward. From central Kansas northeastward into eastern Wisconsin, the powerful derecho led to hundreds of damaging wind reports. At least 57 hurricane-force wind reports were received by the National Weather Service, signaling the most prolific wind event in the United States dating back to at least 2004.[6] Numerous embedded circulations within this rapidly-progressing derecho produced dozens of tornadoes, including 33 that were rated EF2. The culmination of non-thunderstorm, thunderstorm, and tornadic winds caused widespread damage to structures, trees, power lines, and vehicles across the Plains and Midwest. At least 600,000 people lost power on December 15, and temperatures dropped significantly across the affected region following the event, causing accumulating snow, which hindered cleanup and recovery efforts.[7] The storm killed at least 5 people directly, as well as 2 people indirectly through wildfires partly spawned by the storm, and caused at least $1.8 billion (2021 USD) in damages.[4] The number of tornadoes in this event broke a record for largest outbreak in the month of December that had been set less than a week prior. The event also became one of the largest single-day outbreaks in recorded history, with 120 tornadoes occurring over an eight-hour period.[8]
- ^ a b c "Storm summary message". Weather Prediction Center. December 16, 2021. Archived from the original on December 17, 2021. Retrieved December 17, 2021.
- ^ "WPC surface analysis valid for 12/17/2021 at 00 UTC". wpc.ncep.noaa.gov. Weather Prediction Center. December 17, 2021. Archived from the original on December 18, 2021. Retrieved December 18, 2021.
- ^ Andrew Freeman (December 15, 2021). "Historic storm bringing damaging winds, "unprecedented" tornado risk". Axios. Archived from the original on December 15, 2021. Retrieved December 15, 2021.
- ^ a b "Billion-Dollar Weather and Climate Disasters: Events". NOAA. February 2022. Archived from the original on December 25, 2012. Retrieved February 11, 2022.
- ^ "Severe Storms and Extreme Winds - December 15, 2021". National Weather Service Forecast Office in Des Moines, Iowa. December 25, 2021. Archived from the original on December 25, 2021. Retrieved January 4, 2022.
- ^ "Storm Prediction Center 20211215's Storm Reports". National Oceanic and Atmospheric Administration. Storm Prediction Center. December 15, 2021. Archived from the original on December 20, 2021. Retrieved December 31, 2021.
- ^ Joe Lauria (December 16, 2021). "Joe's Weather Blog: The historic storm departs (THU-12/16)". Fox 4 Weather. Archived from the original on December 16, 2021. Retrieved December 17, 2021.
- ^ "December tornado record crushed by historic onslaught of storms in U.S." Washington Post. Archived from the original on December 28, 2021. Retrieved January 11, 2022.
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