Yes, There Are Category 5 Winter Storms; Here's a Ranking of the Most Extreme U.S. Winter Storms

In 2004, Paul Kocin, currently a National Weather Service meteorologist, and Dr. Louis Uccellini, director of the National Weather Service, developed the Northeast Snowfall Impact Scale, or NESIS, to rank and compare Northeast snowstorms.

In a nutshell, widespread heavy snowfall over highly populated areas produces a high NESIS value for a given storm.

Based on these NESIS values, there are five categories of winter storms, somewhat analogous to the Saffir-Simpson Hurricane Wind Scale:

• Category 1: Notable
• Category 2: Significant
• Category 3: Major
• Category 4: Crippling
• Category 5: Extreme

Building off the work of Kocin and Uccellini, scientists at NOAA's National Centers for Environmental Information (NCEI) developed the Regional Snowfall Index (RSI) to rate snowstorms in other regions, mainly east of the Rockies, including the Midwest and South dating to 1900.

Led by Michael Squires, the NCEI team realized they needed to adjust snow thresholds by region. For example, a four-inch snowfall in Dallas, an area less equipped to deal with removing that snow, is more impactful than a four-inch snowfall in Syracuse. 

So, we have two scales: 1) NESIS can capture storms in adjacent eastern regions, but its snow amounts reflect typical Northeast impacts and 2) RSI, a regional index.

In mid-April 2018, Winter Storm Xanto was a record April snowstorm in Minneapolis/St. Paul, the second heaviest snowstorm on record in Green Bay, Wisconsin, dumping in excess of 30 inches of snow in parts of eastern Wisconsin.

Despite that, its RSI index placed it as a Category 4 winter storm in the upper Midwest, though it was the only Category 4 April snowstorm of record in NCEI's upper Midwest region dating to 1900.

In early February 2013, Winter Storm Nemo clobbered New England with several feet of snow and high winds, knocking out power, burying cars and collapsing roofs. Both the NESIS and RSI placed Nemo in Category 3 territory, since it missed several large metro areas including Philadelphia, Baltimore and Washington, D.C.

This brings to light two key caveats of the indices:

1) Wind is not a factor. Remember, the factors are areal coverage of snow, snow amount and population. Not all snowstorms produce blizzard conditions, so this impact is not included.

2) Timing is not a factor. It makes no difference in the NESIS and RSI scales whether a snowstorm occurred on a Sunday in January or during peak Christmas travel.

There have been only 28 Category 5 winter storms in the U.S. since 1900, based on the RSI. The last one was the February 2011 Groundhog snowstorm in the Midwest.

Here is a look at the Category 5 winter storms by region.

East

Given the NESIS scale is more encompassing of the entire East, while the RSI scale is regional, we'll examine both the NESIS and the RSI category-five storms in the Northeast and Southeast. Each extreme storm is ranked in order by the highest NESIS or RSI value, which is listed after each storm.

East Coast NESIS Cat. 5 Storms

1. Superstorm '93 (Mar. 12-14): 13.20
2. Blizzard of '96 (Jan. 5-8): 11.78

Northeast Region (Maryland to Maine) RSI Cat. 5 Storms

1. Feb. 21-27, 1969: 34.026
2. Superstorm '93 (Mar. 11-14): 22.117
3. Blizzard of '96 (Jan. 5-8): 21.708
4. Blizzard of '78 (Feb. 3-7): 18.422

Southeast Region (Virginia to Alabama) RSI Cat. 5 Storms 

1. Blizzard of '96 (Jan. 5-8): 26.373
2. Superstorm '93 (Mar. 11-14): 24.433
3. Feb. 26-Mar. 2, 1927: 24.418
4. Jan. 25-29, 1922: 18.528
5. Jan. 20-23, 1940: 18.14

As you can see, there are two storms that show up in all the extreme winter storm lists above.

Superstorm 1993 laid down a massive swath of 10-inch-plus snowfall from parts of Alabama to Maine. You don't often see snow from the Gulf of Mexico to New England, so by sheer aerial coverage, Superstorm 1993 pops to the top.

The Blizzard of '96 was the snowstorm of record in both Philadelphia and Newark and set the state snowfall record in Virginia (48 inches at Big Meadows), snarling travel and shutting down schools and businesses for days. This mammoth storm spread a 10-inch-plus snow swath from the Ohio Valley to the entire Northeast urban corridor, affecting over 56 million in the Northeast alone.

Of course, since the data only goes back to 1900, there is one glaring omission. Imagine almost two feet of snow, with higher drifts, in New York City, before the advent of the underground subway system, snow plows, or even simply burying wires underground.

Ohio Valley

RSI Cat. 5 Storms (Illinois. to Ohio to Tennessee)

1. Great Appalachian Storm (Nov. 21-29, 1950): 34.693
2. Superstorm '93 (Mar. 11-14): 24.629
3. Groundhog Blizzard 2011 (Jan. 31 - Feb. 3): 21.99
4. Chicago Blizzard of 1967 (Jan. 24-28): 18.128

For truly bizarre storms, the November 1950 storm is my personal favorite, topping any other storms in these particular states, according to the RSI.

Affecting what would have been 49 million people according to current population, the Great Appalachian Storm was so intense and wound up it turned basic meteorology in the northern hemisphere on its head.

At the time of the surface map shown above, Nov. 26, 1950, cold air was blowing in from the south over much the interior Northeast. Conversely, north winds were ushering warmer air into the Ohio Valley from the northern Great Lakes.

Among the incredible totals were Pickens, West Virginia (57 inches), Steubenville, Ohio (44 inches) and Pittsburgh, Pennsylvania (30.5 inches). Virtually all of the Buckeye State picked up 10 inches of snow.

A pair of infamous Chicago snowstorms of 1967 and 2011 made the list, as well.

We didn't forget about the storm dubbed the Cleveland Superbomb of Jan. 1978. The category-three classification in the Ohio Valley region was more of an artifact that the storm was split between regions of the RSI analysis. Remember, the calculations take into account only snowfall and population, not necessarily severity of impact and, of course, not wind.

Upper Midwest

RSI Cat. 5 Storms (Michigan, Wisconsin, Minnesota; Iowa)

1. Superbomb (Jan. 22-27, 1978): 39.072
2. Halloween Storm (Oct. 30-Nov. 3, 1991): 30.175
3. Feb. 6-14, 1985: 27.062
4. Nov. 27-Dec. 1, 1985: 22.185

Yes, the 1978 Superbomb easily topped out the upper Midwest list.

Not far behind was an incredible Halloween Storm 13 years later.

While the Perfect Storm was raking the Eastern Seaboard, a massive snowstorm was obliterating records in the upper Midwest in the days before and after Halloween 1991.

This was the snowstorm of record in Minneapolis/St. Paul, Minnesota (28.4 inches), topping the previous record from the fourth extreme storm on the list above (21.1 inches). Duluth's 36.9-inch snow total was a Minnesota state record.

Northern Rockies and Plains

RSI Cat. 5 Storms (Montana, Wyoming, Nebraska, Dakotas)

1. Apr. 9-14, 1927: 34.201
2. Apr. 24-27, 1984: 25.953
3. Nov. 20-28, 1993: 21.999
4. Jan. 18-25, 1943: 21.137
5. Apr. 14-18, 1920: 20.844
6. Feb. 27 - Mar. 5, 1966: 20.378
7. Dec. 21-28, 2009: 18.674

This region had the most Category 5 storms, some of which occurred after Easter.

Over four days in late April 1984, three to six feet of snow buried the Black Hills of South Dakota and mountains of northern Wyoming and southern Montana.

Blizzard conditions pounded the adjacent plains of the Dakotas. This was widely considered to be the worst winter storm to have affected this area so late in the season.

The 2009 storm probably would have garnered an even higher ranking had the RSI region encompassed the southern Plains, as well. On Christmas Eve 2009, blizzard warnings stretched from northwest Texas to the Canadian border. Drifts to 10 feet were reported in Minot, North Dakota.

South Central

RSI Cat. 5 Storms (Kansas to Texas, Arkansas, Louisiana, Mississippi)

1. Feb. 17-21, 1921: 31.885
2. Jan. 4-8, 1988: 22.641
3. Dec. 18-23, 1929: 21.134
4. Feb. 18-23, 1971: 19.358

The most recent of these big four extreme storms laid out a swath of snow from the Plains of Kansas, Oklahoma and Texas to Mississippi to the Carolinas in the first week of 1988.

Up to 18 inches of snow fell in central Oklahoma. Little Rock, Arkansas, picked up a whopping 13 inches of snow in just 24 hours. This 1988 snowstorm was considered the heaviest snowstorm of the 20th century for the state of Arkansas.

As long as we're mentioning Arkansas, Winter Storm Euclid over Christmas week 2012 clobbered the state, producing the record snowiest Christmas Day in Little Rock (9 inches), and their snowiest day since Jan. 6, 1988.

However, due to the lack of population affected, Euclid only ranked a category-one storm on the RSI. Don't tell that to the hundreds of thousands who lost power around the Christmas holiday, due to the combination of high winds and heavy snow downing trees and power lines. 

To see the entire NCEI list of historical snowstorms dating to 1900, visit the NCEI Regional Snowfall Index page.