Winter Storm Jonas: Fourth Strongest Nor'easter since 1950

The massive blizzard that rocked the Mid-Atlantic and Northeast U.S. last weekend, killing at least 58 and leaving over $2 billion in damage, has been rated the 4th most severe snowstorm to hit the area in the past 66 years, said NOAA. A Category 4 or “Crippling” rating was given to the storm using NOAA’s Northeast Snowfall Impact Scale, also known as NESIS. NESIS scores are a function of the area affected by the snowstorm, the amount of snow, and the number of people living in the path of the storm. Wikipedia has a list of NESIS rankings based on the original scale (created by Paul Kocin and Louis Uccellini] as well as a revised version implemented by NOAA in 2005.

The only stronger storms on the NESIS scale since 1950, according to NOAA, were:

Category 5 - March 1993, Mid-Atlantic/New England
Category 5 - January 1996, Midwest/Mid-Atlantic/New England
Category 4 – March 1960, Midwest/Mid-Atlantic/New England

Insurance broker Aon Benfield said economic losses from the blizzard would likely be at least $2 billion, and added that a similar storm system in January 1996 caused $4.6 billion in losses.


Figure 1. Residents were forced to walk in the streets of Washington, D.C., during and after Winter Storm Jonas. Image credit: Joe Flood, NOAA.

Jonas also ranks high on NOAA’s Regional Snowfall Index
Another way to view Jonas is through the lens of the Regional Snowfall Index (RSI). According to NOAA’s National Centers for Environmental Information, NESIS “can be thought of as a quasi-national index that is calibrated to Northeast snowstorms,” whereas the RSI examines each region of the country independently.

On the RSI, Jonas ranks #6 out of the top 200 Northeast snowstorms since 1900, which is slightly lower than the NESIS ranking (again, only the Northeast region alone is considered when calculating this RSI value). Interestingly, when you look at the total area affected by snowfall over the Northeast region, Jonas was quite unimpressive: #199 out of 200! It was the large snowfall amounts and the large number of people affected that pushed up Jonas’s total RSI rating for the region.

For the Ohio Valley, the RSI for the Jan. 22-24 storm ranks #12 among the top 200 snowstorms, thanks to the heavy snows that struck Tennessee, Kentucky, Ohio, and West Virginia early on. For the Southeast region, the storm came in as #14 due to the heavy amounts in the higher terrain of North and South Carolina and across much of Virginia. Thanks to Stu Ostro, The Weather Channel, for background on the RSI.


Figure 2. Snowfall from Jan. 22 to 24, 2016, was spread across the the Ohio Valley, Southeast, and Northeast regions of the United States as defined in the Regional Snowfall Index (RSI). Image credit: NOAA/NCEI.

More reflections on the big storm
Steve Gregory has an a new Thursday post, Blizzard Overview and Why NYC Got Much More Snow Than Forecast, and wunderblogger Lee Grenci offers his thoughts on the storm in his latest post, Reflections on the "Blizzard" of 2016: A Rant about Transferring Energy to the Coast.

We’ll be back late Friday afternoon with an update on El Niño and California rainfall.

Jeff Masters and Bob Henson