The Great Appalachian Storm of November 1950 was a large extratropical cyclone which moved through the Eastern United States, causing blizzard conditions along the western slopes of the Appalachian Mountains and significant winds and heavy rainfall east of the mountains. Hurricane-force winds, peaking at in Concord, New Hampshire, and in the highlands of New England, disrupted power to 1 million customers during the event.

In all, the storm impacted 22 states, killing 383 people, injuring over 160, and causing US$66.7 million in damage ().National Oceanic and Atmospheric Administration. "NOAA's Top U. S. Weather, Water and Climate Events of the 20th Century" Retrieved on November 25, 2006. U.S. insurance companies paid out more money to their policy holders for damage resulting from the cyclone than for any previous storm or hurricane at the time. The cyclone is also one of only twenty-six storms to rank as a Category 5 on the regional snowfall index.National Oceanic and Atmospheric Administration. Regional Snowfall Index (RSI). Retrieved on November 18, 2014.

It was termed in certain sources as the "Storm of the Century".

Meteorological history The preceding atmospheric state was one of La Niña conditions, the cold phase of El Niño–Southern Oscillation, which favors a storm track from the Ohio and Tennessee Valleys into the Appalachians.Joe D'Aleo. "Some Memorable La Nina November Storms" Retrieved on November 25, 2006. The cyclone initially formed in southeast North Carolina near a cold front on the morning of November 24 as the main cyclone over the Great Lakes weakened. Rapid development ensued as the surface center began to migrate back into a closed 500 hPa-level (14.75 inHg) (around above sea level) cyclone, and the cyclone bombed while moving north through Washington D.C. the next morning. The former occluded front to its northwest became a warm front which moved back to the west around the strengthening, and now dominant, southern low pressure center. By the evening of November 25, the cyclone retrograded, or moved northwestward, into Ohio due to a blocking ridge up across eastern Canada. It was at this time that the pressure gradient was its most intense across southern New England and eastern New York. A wide area of +4 standard deviation 850 mb (hPa) winds occurred. The cyclone moved west over Lake Erie to the north of the upper cyclone before looping over Ohio as the low-level and mid-level cyclone centers coupled. Significant convection within its comma head led to the development of a warm seclusion, or a pocket of low level warm air, near its center which aided in further development due to the increased lapse rates a warmer low level environment affords under a cold low. After the system became stacked with height, the storm slowly spun down as it drifted north and northeast into eastern Canada over the succeeding few days.Clarence D. Smith, Jr. "The Destructive Storm of November 25-27, 1950" Retrieved on November 25, 2006.

United States effects This extratropical cyclone rapidly deepened as it moved up the eastern side of the Appalachians during November 24 and 25 and continued into November 27. Coastal flooding was seen along the U.S. coastline from New Jersey northward.

Southeast In Alabama, all-time record lows for November were set at Birmingham ,"On This Date In 1950 – Historic November Cold Wave", AlabamaWx, November 25, 2019

Kentucky An all-time record low for November was set at Louisville (."Belski's Blog - Comparing the all time coldest November days", WLKY, November 24, 2020

New Hampshire Concord recorded a wind gust of during the height of the storm. Winds at Mount Washington reached ."The Great Southeaster of 1950", NBC Connecticut, November 24, 2017

New York Sustained winds of with gusts to were recorded at Albany, New York. A wind gust of was recorded in New York City. Extensive damage was caused by the wind across New York, including massive tree fall and power outages.Old Farmers Almanac. Weather—Thanksgiving Storms. Retrieved on November 25, 2006. Coastal flooding breached dikes at LaGuardia Airport, flooding the runways.Richard Monastersky. "Acclimating to a Warmer World" Retrieved on November 26, 2006. Flooding extended to New York City's Office of Emergency Management on the Lower East Side, in Manhattan.Alexis S. Nussbaum. Powerful Hurricanes and Northeasters: Threat to the Big Apple. Retrieved on November 26, 2006.

Connecticut Extensive wind damage with tidal flooding along the coast. On the coast structures and railroad tracks washed away. Plows were needed to remove sand from coastal roads. Roofs torn off on the coast and at the University of Connecticut. The tide at New London was , third highest in the last 100 years. Hartford had sustained winds of , the highest ever on record, with gusts also the highest on record were recorded on 3 separate occasions. The sustained wind recorded at Bridgeport is the 4th highest on record. Other gusts included at Bridgeport and at New Haven.The Great Southeaster – November 25, 1950 Meteorologist Ryan Hanrahan November 24, 2012

New Jersey A wind gust of , the strongest ever recorded in New Jersey, occurred in Newark.

North Carolina All-time record lows for November were set at Asheville November 1950: Dr. David Call’s New Book on the Record-Setting Superstorm, College of Sciences and Numanities, November 30, 2022 and Wilmington .

Ohio On the storm's west side, nearly a foot (30 cm) of snow fell on Dayton, Ohio, which combined with the wind and cold temperatures to constitute their worst blizzard on record.Weather Channel. Storms of the Century: #8 – November 1950 "Appalachian Storm." Retrieved on November 25, 2006. Nearly the entire state was blanketed with of snow, with being measured in eastern sections of Ohio. The highest report was from Steubenville.Ron Hahn. November. Retrieved on November 26, 2006. Snow drifts were up to deep. Winds exceeded with gusts as high as . Bulldozers were used to clear roads.Ohio History. November 23-27, 1950: Great Thanksgiving Storm. Retrieved on November 26, 2006. Despite the high winds and snow, the annual football game between the University of Michigan and Ohio State University went on as scheduled in Columbus and was nicknamed the Snow Bowl. When the snow melted during the first four days of December, river flooding occurred in Cincinnati.

Pennsylvania During the height of the storm, record to near-record flooding occurred along the eastern side of the Appalachians across eastern and central sections of the state. The Schuylkill at Fairmount Dam reached its highest stage since 1902. In Pittsburgh, of snow accumulated from this cyclone. Tanks were used to clear the resultant snow.Remember Pittsburgh. Snow Disaster. Retrieved on November 26, 2006. When a warm spell visited the region during the first four days of December, river flooding struck Pittsburgh.

South Carolina All-time record lows for November were set at Charleston () and Greenville ().

Tennessee All-time record lows for November were set at Chattanooga (),Knoxville (),71 years later, Tennessee and Kentucky still fight over the 1950 football national title, KnoxNews, November 25, 2021

West Virginia Parkersburg recorded of snowfall during the passage of this low, which exceeded its snowiest November on record by over . Pickens reported the highest amount from anywhere within the cyclone, with measured. November 1950 became West Virginia's snowiest month on record.National Climatic Data Center. "Climate of 2003 - February West Virginia Drought" Retrieved on November 26, 2006. This remarkably heavy snow led to 160 deaths."The Great Appalachian Storm: Worst in Ohio Valley history", Spectrum News 1, November 25, 2020

Effects in Canada

Ontario This system was a major snowstorm for the area, with in Toronto on November 24. This set a record for single-day snowfall in November.Weather Doctor. Significant Weather Events: Canada. Retrieved on November 26, 2006.

Lasting impact This cyclone was used as a test case for some of the first attempts at numerical modeling of the atmosphere, and is still used as a case study to run recent versions of forecast models. These studies helped create what is now known as the National Centers for Environmental Prediction.Robert E. Kistler, Louis Uccellini, and Paul J. Kocin. "Thanksgiving Weekend Storm of 1950" Retrieved on November 25, 2006.

Other similar storms Storms during the time frames November 8–10, 1913, October 22–25, 1923, and November 19–22, 1952 were considered analogous to this cyclone.Clarence D. Smith, Jr. and Charlotte L. Roe "Comparisons Between the Storms of November 20-22, 1952, and November 25-27, 1950" Retrieved on November 25, 2006. Despite their similarities, there are some differences. For example, the 1913 event was much more destructive to Great Lakes shipping, while the 1950 storm caused greater snowfall amounts.

See also Cyclogenesis Extratropical cyclone Great Lakes Storm of 1913 Great Snowstorm of 1944

References

External links "The Great November 1950 Superstorm" Oocean Weather Services