Great Blizzard of 1978

Meteorological Development

The Great Blizzard of 1978 originated from a complex and powerful atmospheric setup that began late on Tuesday, January 24. Surface weather maps showed a moisture-laden Gulf low-pressure system developing over the southern United States, while a separate and unrelated low was present over the Upper Midwest. A powerful Arctic jet stream containing wind speeds of 110 knots surged straight south through the Northern Great Plains at the same time a powerful subtropical jet with winds of 130 knots moved through Arizona. These streams were forced around a huge upper ridge of high pressure that pushed the Pacific jet north into Northern Canada. The Arctic and subtropical jet streams merged over the central United States, creating a combined wind max of 150 knots that led the deepening Gulf low to undergo explosive cyclogenesis. To meet the definition of explosive cyclogenesis, a storm's central pressure must drop at least 24 millibars in 24 hours, but the Great Blizzard's pressure fell by a remarkable 40 millibars in that period. The storm initially brought rain but changed to heavy snow during the predawn hours of January 26 as Arctic air deepened ahead of the system, leading to frequent whiteouts and zero visibility. As the storm headed for Ohio, the National Weather Service categorized it as a rare severe blizzard, the severest grade of winter storm, and stated it was of unprecedented magnitude.

Record Barometric Pressure and Storm Intensity

The blizzard produced some of the lowest non-tropical atmospheric pressures ever recorded in North America, a direct measure of its ferocious strength. On January 26, the third-lowest atmospheric pressure recorded in the mainland United States, apart from a tropical system, occurred as the storm passed over Mount Clemens, Michigan, where barometer readings fell to 956.0 mb. In Detroit, air pressure fell to 28.34 inches of mercury, equivalent to 960 millibars. The absolute lowest pressure for the entire storm was measured at Sarnia, in Southwestern Ontario, where barometer readings decreased to 955.5 mb. Toronto's pressure fell to 28.40 inches, breaking its previous record by 0.17 inches. The 956.0 mb reading in Mount Clemens was the lowest pressure ever recorded in the Central United States at that time. The lowest confirmed pressure for a non-tropical system in the continental U.S. had been set by a January 1913 Atlantic coast storm. On rare occasions, extra-tropical cyclones with pressures below 28 inches of mercury have been recorded in places like Wiscasset, Maine and Newfoundland, but the 1978 blizzard's intensity over the continental interior was exceptional. The blizzard also achieved the highest score on the Regional Snowfall Index, with a maximum value of 39.07, and is one of only 26 winter storms to reach the scale's Category 5 designation.

Impact in the United States: Paralysis and Response

The blizzard's impact across the Midwestern United States was devastating, widespread, and in many areas described as unprecedented. Ohio experienced its worst blizzard in history, with 51 people dying as a direct or indirect result of the storm. Over 5,000 members of the Ohio National Guard were called in to make numerous rescues, and police asked citizens with four-wheel-drive vehicles or snowmobiles to transport doctors and nurses to hospitals. From January 26 to 27, the entire Ohio Turnpike was shut down for the first time ever, and Major General James C. Clem of the Ohio National Guard later described the total effect on transportation in Ohio as comparable to a nuclear attack. In Michigan, Governor William Milliken declared a state of emergency and called out the Michigan National Guard to aid stranded motorists and road crews. The Michigan State Police pronounced Traverse City unofficially closed and warned area residents to stay home. About 100,000 cars were abandoned on Michigan highways, most of them in the southeast part of the state, and about 20 people died in Michigan due to heart attacks, traffic accidents, or exposure. WTCM radio staffer Marty Spaulding in Traverse City had to walk 10 city blocks in waist-deep snow to reopen the station after regular staff could not reach it due to impassable roads.

Indiana faced similarly extreme conditions on the storm's second day. Half an hour after the storm front passed through, the Indianapolis International Airport was closed due to whiteout conditions. At 3 a.m., the blizzard produced peak winds of 55 miles per hour, and temperatures dropped to 0 °F that morning with wind chills remaining at -40 to -50 °F nearly all day. Governor Otis Bowen declared a snow emergency for the entire state on the morning of January 26. Snow drifts of 10 to 20 feet made travel virtually impossible, stranding an Amtrak train and thousands of vehicles and travelers, leading the Indiana State Police to consider all Indiana roads closed during the afternoon of the 26th. The storm's disruption extended deeply into public life, forcing historic closures. Classes at Ohio State University in Columbus and the University of Notre Dame in Indiana were canceled for the first time in those universities' histories. Purdue University in West Lafayette, where 25 inches of snow fell, closed for only the third time in its history, and Miami University in Oxford, Ohio, closed for the first time since the assassination of President John F. Kennedy. In Indiana, schools were closed for as much as three weeks, and the historic Indiana High School Boys Basketball Tournament was postponed for 17 days.

Impact in Canada

In Canada, the blizzard severely affected southwestern Ontario, bringing hurricane-force winds and heavy snowfall that created dangerous conditions. London, Ontario, recorded 41 centimetres of snow with a maximum wind speed of 128 kilometres per hour. The storm's intense low pressure was felt across the region, with the record-low measurement of 955.5 mb taken in Sarnia representing the storm's central pressure. The disruption extended to the Greater Toronto Area, where deep snow stranded students at Sheridan College's then-rural campus in Brampton. On Thursday afternoon, January 26, school buses could not get through the deep snow to the campus to take students home, and neither could any other vehicles. This logistical failure forced some community college students to stay on campus overnight until conditions improved and travel became possible again. The event demonstrated how a storm centred over the U.S. Midwest could deliver extreme and paralyzing winter conditions to populous regions of Southern Ontario, affecting education and transportation.

Snowfall, Lake-Effect, and Record Totals

The initial blizzard was followed by persistent lake-effect snow squalls, which compounded the snowfall and led to record monthly totals in some areas, particularly east of the Great Lakes. In Muskegon, Michigan, heavy lake-effect snow squalls after the blizzard began contributed to up to 52 inches of snow falling over four days. The combination of persistent lake effect and cyclonic snowfalls in January 1978 resulted in several all-time monthly record snowfall totals to the lee shores of the lower Great Lakes. The cooperative observer station at the Bennetts Bridge power plant, near Altmar, New York, established an official all-time New York State monthly snowfall record with 192 inches of snowfall in January 1978. Several other long-term New York weather stations also set their own all-time monthly records during that January due to the relentless snow. An inch or more of snow, usually much more, remained on the ground across much of the affected Ohio and Indiana area for nearly two months after the storm.

• Bennetts Bridge (near Altmar), NY: 192 inches (all-time NY state monthly record)
• Montague, NY: 150 inches
• Adams, NY: 130 inches
• Watertown, NY: 128 inches

Historical Context and Lasting Legacy

The Great Blizzard of 1978 holds a definitive place in the annals of North American winter weather due to its exceptional metrics and societal impact. It is classified as a Category 5, the highest level, on the Regional Snowfall Index, with a maximum value of 39.07, making it the highest-ranking winter storm on that scale. The storm's central pressure of 955.5 mb recorded in Sarnia remains among the lowest ever measured for a non-tropical system in continental North America. National Weather Service Meteorologist C. R. Snider in Ann Arbor, Michigan, stated on January 30, 1978, that it was the most extensive and very nearly the most severe blizzard in Michigan history. The event is often cited alongside other historic storms like the Great Snowstorm of 1944, the 1971 Great Lakes blizzard, and the Blizzard of 1977. Its combination of ferocious winds gusting up to 111 mph, extreme low pressure, massive snowfall from both the cyclone and lake effect, and a vast geographic impact across multiple states and Ontario secures its reputation as a benchmark for severe winter weather. The storm did extensive damage to the Ohio Valley and the Great Lakes region, and its memory persists in community recollections, university archives, and meteorological studies as an example of nature's potential for widespread disruption.

Questions about Great Blizzard of 1978

How did the blizzard affect Ontario, Canada?

In Canada, the blizzard brought severe conditions to southwestern Ontario. London received 41 centimetres of snow with wind gusts up to 128 km/h. The lowest barometric pressure of the entire storm, 955.5 mb, was recorded in Sarnia. The storm was disruptive enough to strand students overnight at Sheridan College in Brampton when vehicles could not reach the rural campus due to deep snow.

Why was the storm's barometric pressure significant?

The storm produced extraordinarily low atmospheric pressure, a key indicator of its intensity. The reading of 955.5 mb in Sarnia, Ontario, was the storm's lowest central pressure. A reading of 956.0 mb in Mount Clemens, Michigan, was the third-lowest non-tropical pressure ever recorded in the mainland U.S. at that time. Such low pressures in an inland winter storm are rare and signified a system of exceptional strength.

What were the impacts in Ohio and Michigan?

Ohio experienced the worst blizzard in its history, with 51 deaths. Over 5,000 National Guard troops were mobilized, and the Ohio Turnpike shut down completely for the first time. In Michigan, Governor William Milliken declared a state of emergency, the National Guard was deployed, and approximately 100,000 cars were abandoned on highways. Traverse City was effectively closed by state police.

What was the Great Blizzard of 1978?

The Great Blizzard of 1978 was a historic and severe winter storm that struck the Ohio Valley, Great Lakes, and Southern Ontario from January 25 to 27, 1978. It is often cited as one of the most severe blizzards in US history. The storm underwent explosive cyclogenesis, with its central pressure dropping 40 millibars in 24 hours, and produced the third lowest non tropical atmospheric pressure ever recorded in the mainland United States. It brought hurricane force winds up to 179 km/h, caused whiteouts with zero visibility, and produced wind chill values as low as minus 51 degrees Celsius. The National Weather Service categorized it as a rare severe blizzard, the severest grade of winter storm, causing widespread paralysis and numerous fatalities.

What were the snowfall and wind conditions in London, Ontario, during the blizzard?

In London, Ontario, 41 centimetres of snow fell and the maximum wind speed reached 128 kilometres per hour, causing blizzard conditions across southwestern Ontario. This was part of the historic winter storm that struck Southern Ontario from January 25 to 27, 1978. The storm brought heavy snow and powerful winds that created whiteouts and severe drifting. These conditions made travel extremely hazardous and contributed to the storm's significant impact across the region. The measurements from London highlight the intensity of the storm as it moved into Canada.

Where was the lowest barometric pressure recorded during the storm, and what was it?

The absolute lowest pressure was measured in Sarnia, Southwestern Ontario, where barometer readings decreased to 955.5 mb. This reading was lower than the 956.0 mb recorded in Mount Clemens, Michigan, which was the third lowest non tropical pressure in the mainland United States. In Toronto, pressure fell to 28.40 inches, breaking its previous record by 0.17 inches. These exceptionally low pressures were a key indicator of the storm's unprecedented intensity and its classification as undergoing explosive cyclogenesis. The Sarnia measurement shows the severe nature of the system as it affected Canada.

Sources and further reading

• Great Blizzard of 1978 (Wikipedia)
• The Great Blizzard of 1978 (weather.gov)
• 48 years later: Remembering the Great Blizzard of 1978 in ... (clickondetroit.com)

Checked by the Your Space Hamilton desk. Last updated 2026-10-21.