November 2020 North American storm complex

The November 2020 North American storm complex was a major early-season snowstorm that impacted most of the Ohio Valley from November 30–December 2 with heavy snow, gusty winds, and near-whiteout conditions. The system originated from a weak gulf low off the coast of Texas on November 29, which began to move northeastward onto land the next day. It then began to strengthen, as well as slowing its movement down, resulting in heavy, wind-driven snow for prolonged periods of time in the Ohio Valley. It also triggered a major lake-effect snow event from December 1–2 as the system stalled over Lake Ontario, resulting in additional heavy snowfall. The storm system was also responsible for a severe thunderstorm outbreak in the Southeast and Mid-Atlantic regions, causing 22 severe thunderstorms and 5 tornadoes. In total, the system is estimated to have caused at least $100 million (2020 USD) in damages.[1] It was unofficially named Winter Storm Dane by The Weather Channel.[2]

November 2020 North American storm complex
GOES-16 satellite imagery of the storm complex impacting the Ohio Valley at 16:31 UTC (11:31 a.m. EDT) on November 30
Meteorological history
FormedNovember 29, 2020
DissipatedDecember 2, 2020
Winter storm
Highest gusts115 km/h (70 mph)
Lowest pressure993 hPa (mbar); 29.32 inHg
Maximum snowfall or ice accretion24 in (61 cm) at Thompson, Ohio
Tornado outbreak
Tornadoes5
Maximum ratingEF1 tornado
Duration12 hours, 43 minutes
Overall effects
FatalitiesNone confirmed
Damage>$100 million (2020 USD)[1]
Areas affectedSouthern United States, Ohio Valley, Northeastern United States, Eastern Canada
Power outages>100,000

Part of the 2020–21 North American winter and tornado outbreaks of 2020

Meteorological history

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The system formed as a weak low-pressure system off the coast of southeastern Texas early on November 29. After meandering eastward for around 12 hours, the low-pressure made landfall and came ashore in southeastern Louisiana at 18:00 UTC.[3] It then turned northeastward, beginning to strengthen and spawning a secondary low-pressure to the east.[4] By 15:00 UTC on November 30, the system had spawned two more low-pressures, and the main low had reached an initial intensity of 995 millibars (29.4 inHg).[5] The system reached a peak intensity of 993 millibars (29.3 inHg) at 00:00 UTC on December 1, while two of the low-pressure areas dissipated and the main low stalled out over Lake Ontario.[6] Another low-pressure dissipated a few hours later, leaving only the main low remaining, which began to slowly weaken.[7] The system continued weakening throughout December 1, and by early on December 2, it had begun moving to the northeast again.[8] After continuing to weaken for several hours, it dissipated late on December 2.[9]

Preparations and impact

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A map of observed snowfall accumulation reports in the Ohio Valley and Appalachians from the storm

Winter Storm Warnings were issued in parts of Ohio and Pennsylvania, mainly along the shores of Lake Erie due to the potential for heavy snow. Winter Weather Advisories were issued in a broad swath farther south, stretching all the way down to eastern Tennessee.[2]

Ohio Valley

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A fairly large area of Ohio and Pennsylvania picked up over 10 inches (25 cm) of snow, with the highest totals near Lake Erie. Snow fell in Cleveland all day November 30, and the city saw 10.1 inches (26 cm) of snow during the event. Areas near Cleveland, such as Thompson, Ohio, saw as much as 24 inches (61 cm) of snow, due to lake-effect enhancement. Trees and power lines were downed in the Cleveland area due to the heavy snow and strong winds.[2] Elnora, Indiana had received nearly 7 inches (18 cm) by the time snow had ended.[10] Detroit, Pittsburgh, Columbus, and other areas further away from Lake Erie generally saw 1–4 inches (2.5–10.2 cm) of snow from the system.[2]

Southern Appalachians

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In Arab, Alabama, 1 inch (2.5 cm) of snow was measured. Around 0.5 inches (1.3 cm) of snow was reported in the Murfreesboro, Tennessee area. The Gatlinburg and Pigeon Forge areas had seen up to 5 inches (13 cm). By the end of the night, Mount Le Conte, Tennessee had seen 11 inches (28 cm) inches of snow, as reported by the National Weather Service.[10] Roan Mountain, Tennessee had seen 12 inches (30 cm) by the time snow and finished, and Robbinsville, North Carolina picked up a total of 15 inches (38 cm) from the system.[2]

Northeast

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On November 30, the Verrazano Narrows Bridge closed all lanes due to high wind conditions.[11] The bridge shaking resulted in viral social media videos.[12]

Severe weather

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The warm side of the system also resulted in some severe thunderstorms in the Southeast and Mid-Atlantic regions. Several of the storms became tornadic, with at least five tornadoes being confirmed on November 30. The storms also resulted in 22 reports of wind damage in an area from Maryland to eastern Pennsylvania.[13][14]

Confirmed tornadoes by Enhanced Fujita rating
EFU EF0 EF1 EF2 EF3 EF4 EF5 Total
1 2 2 0 0 0 0 5

Confirmed tornadoes

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List of confirmed tornadoes – Monday, November 30, 2020[note 1]
EF# Location County / Parish State Start Coord. Time (UTC) Path length Max width Summary
EF1 NNW of Hamburg to SE of Nankin Madison FL 30°35′32″N 83°31′20″W / 30.5923°N 83.5222°W / 30.5923; -83.5222 (Hamburg (Nov. 30, EF1)) 08:10–08:18 5.52 mi (8.88 km) 475 yd (434 m) Significant tree damage and minor damage to a home occurred near where this tornado touched down. The tornado was at its strongest and its widest point as it continued to significantly damage trees, and cause damage to multiple farm outbuildings. As the tornado narrowed, it snapped many pine trees. The tornado lifted near SR 53, just south of the Florida/Georgia state border.[15]
EFU East Lake to NE of Odessa Pinellas, Hillsborough, Pasco FL 28°06′N 82°41′W / 28.1°N 82.69°W / 28.1; -82.69 (East Lake (Nov. 30, EFU)) 11:00–11:25 12.45 mi (20.04 km) 50 yd (46 m) Despite this tornado touching down intermittently for over 12 mi (19 km), only damage reported was downed tree limbs and blown around patio furniture.[16][17]
EF1 E of Port Deposit to Woodlawn Cecil MD 39°38′38″N 76°03′47″W / 39.644°N 76.063°W / 39.644; -76.063 (Port Deposit (Nov. 30, EF1)) 19:37–19:42 3.36 mi (5.41 km) 75 yd (69 m) Many trees were snapped or uprooted at the beginning of the path, including some near a home. As the tornado moved northeast, it damaged newly installed power poles near another home. Additional trees and power poles were damaged. The tornado was at its strongest point when a front porch awning was lifted. Damage to other homes occurred, including damage to roof shingles and siding. One home's garage door was bent inward. Trees were snapped or uprooted along the rest of the path before the tornado lifted.[18]
EF0 NNW of Baltimore Corner to SW of Templeville Caroline MD 39°04′03″N 75°51′07″W / 39.0675°N 75.8520°W / 39.0675; -75.8520 (Baltimore Corner (Nov. 30, EF0)) 20:13–20:20 5.32 mi (8.56 km) 75 yd (69 m) This tornado first touched down along MD 313, just south of the Caroline/Queen Anne's county border. Little to no damage was found in this area, however, a small tornado debris signature appeared on doppler radar. As this tornado moved northeastward, it passed northwest of Henderson. In this area, a small horse barn was destroyed, with its walls collapsed, and its roof blown across a yard into a nearby home. The nearby home had damage done to its roof, siding, and chimney. Several trees and tree branches were snapped or uprooted. Later on down the path, two barns were destroyed. One of the barns' roofs was lifted and tossed, while the other was peeled and twisted. The tornado continued northeast before lifting.[19]
EF0 Montgomeryville Montgomery PA 40°14′N 75°14′W / 40.23°N 75.24°W / 40.23; -75.24 (Montgomeryville (Nov. 30, EF0)) 20:52–20:53 0.87 mi (1.40 km) 100 yd (91 m) A brief tornado touched down just east of the PA 309 northbound onramp to the US 202 parkway. As the tornado crossed the US 202 parkway, two small trees were uprooted. Wooden picnic tables outside of a Texas Roadhouse were tossed, shattering the front window of a nearby closed restaurant. This same restaurant had air-handling equipment and siding torn from the building. Six to eight cars in the parking lots of both the Texas Roadhouse and the nearby restaurant were either shaken or tossed by the tornado. Several small tree branches were snapped in the area. Metal light posts were bent at the base, and two stop signs were either bent over or removed from the ground. A supporting pole at the entrance of a nearby Staybridge Suites was damaged. The tornado inflicted minor damage to roofing at a Costco before lifting less than one minute after it touched down.[20]

See also

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Notes

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  1. ^ All dates are based on the local time zone where the tornado touched down; however, all times are in Coordinated Universal Time for consistency.

References

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  1. ^ a b "Global Catastrophe Recap – November 2020" (PDF). Aon Benfield. December 10, 2020. p. 4. Retrieved March 6, 2021.
  2. ^ a b c d e "Winter Storm Brought Wind-Driven Snow to Eastern Great Lakes, Appalachians". weather.com. December 2, 2020.
  3. ^ "WPC Surface Analysis Archive".
  4. ^ "WPC Surface Analysis Archive".
  5. ^ "WPC Surface Analysis Archive".
  6. ^ "WPC Surface Analysis Archive".
  7. ^ "WPC Surface Analysis Archive".
  8. ^ "WPC Surface Analysis Archive".
  9. ^ "WPC Surface Analysis Archive".
  10. ^ a b Sadler, Megan (5 December 2020). "More snow at LeConte Lodge creates magical winter scene". WVLT.
  11. ^ High wind conditions lead to closures on Verrazzano-Narrows Bridge, News 12 The Bronx, December 1, 2020
  12. ^ Watch a harrowing video of the Verrazzano Bridge rocking and groaning in Monday's high winds, Timeout, December 2, 2020
  13. ^ "Storm Prediction Center 20201129's Storm Reports". www.spc.noaa.gov. Retrieved 3 December 2020.
  14. ^ "Storm Prediction Center 20201130's Storm Reports". www.spc.noaa.gov. Retrieved 3 December 2020.
  15. ^ Florida Event Report: EF1 Tornado (Report). National Centers for Environmental Information. 2020. Retrieved January 1, 2023 – via National Weather Service in Tallahassee, Florida.
  16. ^ Storm Events Database November 30, 2020 (Report). National Centers for Environmental Information. Retrieved February 24, 2021.
  17. ^ Florida Event Report: EFU Tornado (Report). National Centers for Environmental Information. 2020. Retrieved January 1, 2023 – via National Weather Service in Tampa, Florida.
  18. ^ Maryland Event Report: EF1 Tornado (Report). National Centers for Environmental Information. 2020. Retrieved January 1, 2023 – via National Weather Service in Baltimore, Maryland.
  19. ^ Maryland Event Report: EF1 Tornado (Report). National Centers for Environmental Information. 2020. Retrieved January 1, 2023 – via National Weather Service in Philadelphia, Pennsylvania.
  20. ^ Storm Events Database November 30, 2020 (Report). National Centers for Environmental Information. Retrieved February 24, 2021.
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