Great Appalachian Storm of November 1950: Impacts on Pennsylvania
Great Appalachian Storm of November 1950
75 years ago, Pennsylvanians had celebrated Thanksgiving not knowing the full scope of the major storm that was about to unleash its wrath across the state. In many different ways the storm was described as the worst ever for specific localities. Join me in looking back at the Great Appalachian Storm of November 1950 and how it impacted Pennsylvania.
Background
The weather in fall of 1950 featured a number of notable events in Pennsylvania. In September a cold front brought Canadian wildfire smoke over the state that turned day to night, as highlighted in a previous blog post. October was relatively quiet with plenty of warmth and higher than average humidity. There were thunderstorms with hail throughout the month.
November started out with a heatwave on the 1st and 2nd that not only broke record daily high temperatures, but also November monthly record high temperatures. For most major reporting stations in the state, these daily and monthly records still stand 75 years later! The heatwave broke on the 3rd but it didn't go quietly. Strong storms struck southeastern Pennsylvania with an F3 tornado carving an 8 mile path through portions of Lancaster and Berks Counties. To date, this remains the only F3/EF3 to strike Pennsylvania during the period from October to February!
While these events were noteworthy, the most impactful storm was yet to come.
Storm Setup
On November 24, 1950, a low began to develop near the Carolinas. Another key ingredient was a strong high over Labrador, Canada, with a central minimum pressure of 1,049mb. The low deepened 24mb in a 24 hour period ending 15z on the 25th. As it did so, the low took an unusual track thanks to the blocking high, moving to the northwest from the Carolinas, across Pennsylvania and into northeast Ohio where it stalled.
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| Surface weather charts from 1200 GMT on 11/24/1950 and 0000 GMT on 11/25/1950 via November 1950 Monthly Weather Review. |
The gradient between high and low pressure was quite extreme. Caribou, Maine, recorded a pressure of 1,042mb while Dayton, Ohio, set their November low pressure record at 983.7mb which still stands today.
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Surface weather charts from 1200 GMT on 11/25/1950 and 0000 GMT on 11/26/1950 via November 1950 Monthly Weather Review. |
The storm notably brought frigid air deep into the southern US. Atlanta dropped to 3°, 11° colder than the second coldest November temperature on record. Ten states broke all time November record low temperatures. Remember the heatwave I mentioned above? 13 states set all time November record high temperatures early in November. At the time, 4 states (Georgia, Michigan, Missouri, and Virginia) broke both records in the same month! Crop damage was widespread in the southeast CONUS.
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Southwestern PA remained in the cold sector for the entire storm keeping the precipitation as snow. To the east, warmer temperatures kept the precipitation as rain. In between, a mix of snow, sleet, and freezing rain stretched along the Allegheny Front. Note the warmth in northwestern PA. This area saw plain rain that changed to snow thanks to strong east wind that brought warmer air on the northern side of the storm followed by a sharp temperature drop. Buffalo, NY, recorded a high of 57° and just 0.5" of snow!
Western PA Heavy Snow
The heavy snow that fell in western Pennsylvania set records that still stand today. The heaviest snow fell on the 25th with 24 hour totals of over 30 inches. Washington reported 38" breaking the old record of 36". The storm also remains the largest snowstorm in Pittsburgh with 27.4" falling over 3 days.
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Many buildings collapsed under the heavy weight of the snow. Johnstown reported collapsed roofs of more than a dozen buildings. A roller rink in Indiana County was also a casualty of the heavy snow. A caved in roof a a garage in Bentleyville destroyed 15 vehicles. The snow shut down factories and mines. The National Guard was brought in to close the streets of Downtown Pittsburgh so snow clearing could proceed smoothly.
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| The storm of November 1950 remains the largest 24hr snowfall for 8 counties in western Pennsylvania. |
Hundreds of motorists travelling home following Thanksgiving were stranded for days due to the deep & drifting snow in western Pennsylvania. To keep more from becoming stranded, the PA Turnpike was closed west of Bedford, the first time a section had been closed in the 10 years of operation. This resulted in an overflowing of hotel rooms in Breezewood and Bedford, therefore westbound traffic on the Turnpike was suspended as far east as Carlisle. 500 stranded travelers were taken into homes of Somerset with schools and churches also setting up shelter for stranded motorists in western PA.
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| Total snowfall and greatest snow depth for the month of November 1950 via Climatological Data Pennsylvania November 1950. |
The heavy snowfall in Pittsburgh caused the Penn State versus Pitt football game to be moved both date and location. The rivalry matchup was originally scheduled for November 25th at Pitt Stadium. The game was rescheduled for December 2nd at Forbes Field which had less snow to be cleared. Penn State won 21-20 in what became known as the 'Mud Bowl.' The Michigan versus Ohio State game in Columbus, Ohio, was not delayed and was played in the heavy snow. The 'Snow Bowl' became instant classic with Michigan winning 9-3.
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| View of Pittsburgh during the snowstorm. Image credit: Photo by Walter Stein, Carnegie Library Collection. |
November 1950 ranks as the snowiest November on record for Erie (30.3"). At the time it was the 2nd snowiest month on record, but today it is tied for 17th snowiest.
Snow melted in early December resulting in moderate river flooding on December 4th to 6th. One weather observer in Corry reported a snow water content of 3.12".
Central PA Disastrous Ice
By far the hardest hit by ice was a portion of Blair County with 2" to 4" of ice on trees and power lines. Sleet started to fall in Altoona around 7:30pm on the 24th. At about midnight the temperature rose, changing the precipitation to freezing rain which fell from 1am to 11am. Branches began breaking between 3am and 4am with conditions continuing to deteriorate and by 7am the entire city had lost power. Every transmission line into the city was destroyed. By 11am the temperature dropped from 31° to 25° and the precipitation changed to snow but the damage had been done.
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| The power of the ice took out the steel transmission lines in Altoona. Just one picture of many in the 'Storm Scenes' publication by the Altoona Mirror. The paper originally printed 10,000 copies of the commemorative booklet for $0.50 each. At least 4,000 additional copies were printed due to overwhelming popularity. Image credit: Storm Scenes |
Conditions were drastically different on the mountain as the precipitation had stayed as snow for the entire event in Ebensburg (~16 miles to the west of Altoona). The Associated Press reported that 200,000 were without power in the area surrounding Altoona (the population of Blair County in 1950 was 140,000). Work to restore power was slow as workers were stranded at home. Getting power to the hospitals and Veteran's Home was the first priority.
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| Over an inch of ice accumulated on power lines in Altoona. Image credit: Storm Scenes |
The temperature dropped to a low of 7° the following morning. Temperatures would not rise above 32° until the 30th and light snow continued to fall. To prevent further damage, crews worked to de-ice power lines that didn't fall but were still covered in ice. The Altoona Mirror reported on December 6th that the number without power had been reduced to 4,000 customers.
Eastern PA High Winds
The storm was described as a hurricane and much of the damage resembled that of a tropical cyclone in the eastern half of Pennsylvania. Roofs blown off, trees blown down, power and telephone lines were down, and windows blown out. Many barns were blown over and radio antennas were toppled. Trees fell onto houses. Some buildings were shifted off their foundations. Streets were littered with street signs and other debris. Buildings that had roof damage also had water damage combined with the heavy rain.
Some recorded wind gusts:
Planes and/or hangars were damaged at airports in Bloomsburg, Philadelphia, Lansdale, Towanda, Norristown, Stroudsburg, and Mount Pocono. A 700 pound church bell fell through the roof of the Christ Episcopal Church in Berwick, crashing into the basement. The strong wind bent a flag pole in half in Littlestown. Thousands of windows were blown out in Philadelphia. A church Steeple was toppled in Orwell.
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| November 1950 weather observation comments from Mount Pocono. |
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| Weather observations from Gettysburg noting the wind damage. |
Widespread Flooding
Heavy rainfall on the 25th brought widespread 2" to 4" with isolated totals over 6". Flooding occurred along the Allegheny, Susquehanna, Juniata, Lehigh, and Schuylkill Rivers.
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| Total precipitation recorded on 11/25/1950. |
Main streets of Lewistown, Lock Haven, and Tyrone, flooded. From Renovo to Lewisburg to Harrisburg, numerous towns along the Susquehanna suffered from flooding. However, Williamsport and Sunbury were spared from flooding due to new flood walls built following the 1936 Saint Patrick's Day Flood.
75% of Lock Haven was flooded in what was reported as the second worst flood behind the flood of 1936. A dam upstream of Lock Haven in Mill Hall burst, adding to the flood level. The river rose 14 feet in 12 hours. 100 planes were flooded at the Lock Haven Airport. To the south, 2,000 residents were evacuated in Lewistown. More than 400 Toy for Tots donations for the upcoming Christmas season were lost in flood waters in Tyrone.
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| Flooding in downtown Tyrone. Image credit: Storm Scenes |
Moderate flooding also impacted portions of northwestern PA including Warren, Bradford, Saint Marys, Johnsonburg, Ridgway, and Coudersport. Water overtopped bridges by 2 feet in Bradford and washed out a pedestrian bridge. In Kane the weight of rain that fell onto the snow covered roof caused the collapse of a brand new factory that had been rebuilt following a fire earlier in the year.
Many of the locations in northern Pennsylvania credited the drop in temperatures and changeover to snow for limiting flood damage. The temperature dropped 10° in 6 minutes in Smethport. Corry recorded a temperature drop from 41° to 13° in 3 hours. Had the changeover not occurred, it is believed that river crests likely would have exceeded 1936 levels.
Reading recorded a 24 hour rainfall total of 6.08" ending on the morning of the 25th. Today this still ranks as the 5th wettest day ever for Reading with records going back to 1858!
Crews conducted water rescues in Bucks County as villages were isolated. Water as deep as 20 feet deep was reported near Neshaminy. Manufacturing plants in Conshohocken worked to move machinery and stock to higher ground. Every cellar in the Doylestown area reported some water. 1,000 basements in Scranton were flooded and a landslide was reported near Wilkes-Barre.
Not all the flooding was due to the heavy rainfall. Tidal flooding along the Delaware River in Philadelphia resulted in the evacuation of 200 families with an additional 200 families in Delaware County. The river crested at 10.49" in Philadelphia which still ranks as the 3rd highest crest on record.
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| Pennsylvania Precipitation timeseries for November. Source |
November 1950 ranks as the 2nd wettest November on record for Pennsylvania. The wettest spots in Pennsylvania recorded over 10 inches for the month.
Wrapping Up
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| Snow totals for 11/22/1950 to 11/30/1950. Source |
During the storm, many fires also broke out statewide and the weather conditions hindered responses. Three children died in a fire in Bellefonte. Nearby at the Penn State campus, a fire damaged a dormitory. Two died in a house fire in Butler and a theater burned down in Perkasie. A house in York burned to the ground from a fire caused by lightning.
One storm of recent memory had some similarities to the storm in 1950: Hurricane Sandy in 2012. Like the Great Appalachian Storm, Sandy moved in a similar unusual way, from east to west. Sandy did not have as much cold air to work with occurring a month earlier, keeping the heavy snowfall confined to the higher elevations. Still, Sandy brought heavy wind and rain to much of Pennsylvania.
While it is hard to verify exact numbers, over 300 died across the country as a result of the storm with approximately 40 indirect and direct fatalities in Pennsylvania. The Great Appalachian Storm of November 1950 is certainly one of the strongest storms to have impacted Pennsylvania in recorded history.
Looking Ahead
If you enjoyed this post, consider signing up to receive future blog posts in your email here. There is plenty of Pennsylvania weather posts coming up. The November review will be coming in about a week. As the calendar flips to the last month of the year, it is time to start thinking about the year in review, too!
Thanks for reading, and remember to always look up!
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