A Category 4 "crippling" rating has been given to Winter Storm Jonas on the Northeast Snowfall Impact Scale (NESIS) that is used to rank Northeast snowstorms.
The scale ranks significant snowstorms in the Northeast region Category 1 to Category 5, and was developed in 2004 by Paul Kocin, a meteorologist with the National Weather Service, and Dr. Louis Uccellini, director of the National Weather Service. In a nutshell, widespread heavy snowfall over highly populated areas produces a high NESIS value for a given storm.
The NESIS scale ranking categories.
NOAA said a NESIS value of 7.66has been given to Jonas, which falls solidly in the middle of the Category 4 values from 6 to 9.99. A value of 10 or more is needed to get the highest ranking of Category 5 "extreme" on the NESIS scale.
Jonas is just the 10th storm to rank as a Category 4 on the NESIS scale, and the first since Jan. 21-24, 2005, or a span of more than a decade. Jonas is fourth overall among the top snowstorms in the NESIS rankings dating to 1950. Only two storms in history have ranked Category 5 on the scale, the Blizzard of 1996 and the March 1993 Superstorm.
To be clear, the NESIS scale is only for Northeast snowstorms as its name implies. A separate scale, the Regional Snowfall Index (RSI), is also used to rank storms in the Northeast and other regions of the country. NOAA announced that Jonas ranked as a Category 4 "crippling" storm on the RSI scalefor not only the Northeast region, but also the Southeast.
(MORE:Ranking Most Extreme Winter Storms)
An analysis of the snowfall from Jonas.
(NOAA)
Of course, Jonas was the benchmark storm for some individual locations across the large area it affected, including places with a long period of record.
(MORE: Winter Storm Jonas Records Recap)
This includes Baltimore where the storm total of 29.2 inches at BWI airport beat the President's Day II storm of Feb. 16-18, 2003, that dumped 26.8 inches. Records there date back to 1892. The 30.2 inches of snow Harrisburg, Pennsylvania, saw ranked as the heaviest snowstorm there dating to 1888, according to the National Weather Service.
Though the period of record is shorter, Jonas was also the heaviest snowstorm for New York's LaGuardia and JFK airports, dating back to the 1940s.