NESIS rating? Boxing Day Blizzard

[RU848789]

I went by this: Wikipedia

Not saying it's right, but it has NYC as #1, PHL as #6, BOS as #20, BAL as #21, and DC as #27.

Metro areas do put DC at #8 upon looking deeper, so my apologies.

Metro areas: http://en.wikipedia.org/wiki/Table_of_United_States_Metropolitan_Statistical_Areas

NYC Metro: 19.1 MM

Philly Metro: 5.9 MM

DC Metro: 5.6 MM

Boston Metro: 4.8 MM

Baltimore Metro: 2.7MM

DC + Balt is 8.3 MM, which would put it 4th in the US. However, from a pure numbers perspective, NYC Metro is as large as the other 4 metro areas combined, which is why I think this storm is at least a mid to high end 3, as I said before. I think it's close to a 5 for NYC Metro (it's 2nd most ever for most of Central Jersey, after Jan 1996), it's probably a 3 for Boston, a 3 for Philly and a 1 for DC and a 1 for Balt, which averages out to a 2 for all of those areas, combined (assuming similar pops for each which isn't really correct, but I'm estimating here), and a 5 for NYC and a 2 for the other 4 areas combined works out to a 3.5 overall. Which is what I said in my post the other day. My guess is the extra juice from NC/SE VA gets cancelled by the lack of snow well inland in PA/NY/New England. These inland areas are large areas, though, so that may bring the overall score down a bit from 3.5.

Has anyone seen an overall snowfall map for the entire northeast or even portions of the NE?

[MJW155]

You'll find the formula right dab in the middle of the page: http://www.ncdc.noaa...d-ice/nesis.php "A" stands for area and "P" stands for population. So, your scenario of a 2-4" snowstorm in the south would be well below 1.0 in NESIS rating. In other words, the rarity of the event has nothing to do with its rating. The formula is not that hard to understand. It's NCDC's map production using GIS and statistical smoothing that's harder to understand.

See if that is the case, I don't like the NESIS rating. Areas like Florida getting 4 inches of snow are going to be effected a lot more than DC or Boston getting a foot of snow. Crops would be destroyed, no snow plows, ect. It just has a much bigger effect, IMO.

I think it's fair to say NYC getting hit by a minimum Cat. 1 Hurricane would create more problems than a high end Cat. 1 hitting Miami.

[gymengineer]

See if that is the case, I don't like the NESIS rating. Areas like Florida getting 4 inches of snow are going to be effected a lot more than DC or Boston getting a foot of snow. Crops would be destroyed, no snow plows, ect. It just has a much bigger effect, IMO.

I think it's fair to say NYC getting hit by a minimum Cat. 1 Hurricane would create more problems than a high end Cat. 1 hitting Miami.

Well, the scale was made for Northeast snowstorms (part of the name). It's calibrated to the 13 state region that KU included in their snowstorm books (the denominator in the formula is the mean from the 30 cases in the KU Northeast Snowstorm book). I guess someone else might make a Southern or Great Plains or Pacific Coast snowstorm scale at some point.

[gymengineer]

DC + Balt is 8.3 MM, which would put it 4th in the US. However, from a pure numbers perspective, NYC Metro is as large as the other 4 metro areas combined, which is why I think this storm is at least a mid to high end 3, as I said before. I think it's close to a 5 for NYC Metro (it's 2nd most ever for most of Central Jersey, after Jan 1996), it's probably a 3 for Boston, a 3 for Philly and a 1 for DC and a 1 for Balt, which averages out to a 2 for all of those areas, combined (assuming similar pops for each which isn't really correct, but I'm estimating here), and a 5 for NYC and a 2 for the other 4 areas combined works out to a 3.5 overall. Which is what I said in my post the other day. My guess is the extra juice from NC/SE VA gets cancelled by the lack of snow well inland in PA/NY/New England. These inland areas are large areas, though, so that may bring the overall score down a bit from 3.5.

Has anyone seen an overall snowfall map for the entire northeast or even portions of the NE?

That's not how the rating is calculated at all, though. Even if it were, you have to remember it's possible to rate below a Category 1 on the scale... the storm has to register a 1-2.499 in its rating to qualify as a category 1. So, I guess in your scheme, DC and Baltimore would be category 0's.

[A-L-E-X]

That's not how the rating is calculated at all, though. Even if it were, you have to remember it's possible to rate below a Category 1 on the scale... the storm has to register a 1-2.499 in its rating to qualify as a category 1. So, I guess in your scheme, DC and Baltimore would be category 0's.

How much of a weight is given to population? Because, with the NYC metro area far outnumbering all the other major metros in population (and its not even close), areal distribution gets trumped by population density of the affected area-- something which anyone who would categorize it as a 2 or lower cant comprehend.

BTW anyone arguing between low end or high end Cat 3 is just splitting hairs-- a Cat 3 is a Cat 3 is a Cat 3.

[MJO812]

Paul Kocin said on his facebook that he thinks this is a 2.

[A-L-E-X]

Paul Kocin said on his facebook that he thinks this is a 2.

So its lower than any of the storms last winter? That doesnt make any sense-- UNLESS, population isnt as important of a factor as areal coverage. In which case, it probably should be a 2, because it only affected coastal areas and areas near the coast.

I read something in the Times where it said that 80 million people were affected by heavy snow-- but if areal coverage is more important than the number of people affected, than that stat doesnt matter.

[psuhoffman]

So its lower than any of the storms last winter? That doesnt make any sense-- UNLESS, population isnt as important of a factor as areal coverage. In which case, it probably should be a 2, because it only affected coastal areas and areas near the coast.

I read something in the Times where it said that 80 million people were affected by heavy snow-- but if areal coverage is more important than the number of people affected, than that stat doesnt matter.

The February 5th-6th storm affected an enormous area with 12" plus snowfall. The metro areas of Columbus, Pittsburgh, Richmond, DC, Baltimore, and Philadelphia all received significant snowfall. The amounts in that storm also surpassed the severity of this storm even where those significant bands in NJ set up. There was a very widespread area of 20" plus snowfall in the Feb storm, and a fairly widespread area of 30" snowfall and even some amounts approached 40" in several places. So the population affected if you add in the significantly greater aerial coverage of the storm was probably close to equal, then when you add in the fact that the snowfall was significantly greater of a much larger area in the February storm last year and it makes perfect sense that it would be rated higher. This storm was a bigger snow for NYC but in terms of historical significance from purely the perspective of how rare a meteorological event it was the Feb 5th event was vastly bigger.

[Sunny and Warm]

The February 5th-6th storm affected an enormous area with 12" plus snowfall. The metro areas of Columbus, Pittsburgh, Richmond, DC, Baltimore, and Philadelphia all received significant snowfall. The amounts in that storm also surpassed the severity of this storm even where those significant bands in NJ set up. There was a very widespread area of 20" plus snowfall in the Feb storm, and a fairly widespread area of 30" snowfall and even some amounts approached 40" in several places. So the population affected if you add in the significantly greater aerial coverage of the storm was probably close to equal, then when you add in the fact that the snowfall was significantly greater of a much larger area in the February storm last year and it makes perfect sense that it would be rated higher. This storm was a bigger snow for NYC but in terms of historical significance from purely the perspective of how rare a meteorological event it was the Feb 5th event was vastly bigger.

Agreed. The Feb 5-6 event had 12"+ from the spine of the Appalachians on East from the VA/NC border through SNE. 18"+ area was from just West of the big cities to the coast. In terms of areal coverage and amounts, they were two different beasts. Both were great events, but this past event was along I95 from Phiily to Boston, and barely anything NW of that line except in NE.

[A-L-E-X]

The February 5th-6th storm affected an enormous area with 12" plus snowfall. The metro areas of Columbus, Pittsburgh, Richmond, DC, Baltimore, and Philadelphia all received significant snowfall. The amounts in that storm also surpassed the severity of this storm even where those significant bands in NJ set up. There was a very widespread area of 20" plus snowfall in the Feb storm, and a fairly widespread area of 30" snowfall and even some amounts approached 40" in several places. So the population affected if you add in the significantly greater aerial coverage of the storm was probably close to equal, then when you add in the fact that the snowfall was significantly greater of a much larger area in the February storm last year and it makes perfect sense that it would be rated higher. This storm was a bigger snow for NYC but in terms of historical significance from purely the perspective of how rare a meteorological event it was the Feb 5th event was vastly bigger.

Yes, that storm did have much bigger aerial coverage, but I thought the boxing day blizzard also affected areas of the deep south and the coastal carolinas all the way up to Norfolk, Virginia with very heavy snow. About rarity, I think both were extremely rare events; I dont know how one can judge which one was rarer-- one had tremendous snowfall amounts over a much larger area, the other one had amazingly intense low pressure of 960 mb with hurricane force wind gusts in a moderate la nina. I have a hard time deciding which event is more rare and I dont want to show a NYC bias (since the storm from last year had zero effects on NYC or Boston), but I would think an intense 960mb storm causing very heavy snow from Norfolk to Philly to NYC to Boston in a mod la nina when people said you couldnt have this kind of storm in this kind of pattern would be more rare-- but again, it's hard to judge rarity. Especially if we get another storm like that this season.

[Analog96]

Paul Kocin said on his facebook that he thinks this is a 2.

I don't know how it could be rated that low. I'd like to see Paul's reasoning for that.

[A-L-E-X]

I don't know how it could be rated that low. I'd like to see Paul's reasoning for that.

I see his reasoning if the scale is mostly slanted towards areal coverage. But, to put things in perspective, if we had a scale like that for hurricanes, Andrew would likely have been a Cat 1 or maybe a Cat 2, because it did make a second landfall.

A storm like Donna from 1960 would probably have been at the top of the scale.

[ace0927]

I think its time that winds be factored into the equation also-- as winds obviously impact the severity of any storm. And densely populated areas just west and south of NYC got 24-32 inches. What was the ranking for March 1960? I would rank this similarly.

alex- march 60 is the 3rd highest rated storm of all time...8.77...not happening...maybe you mean march 58?

[ace0927]

To put it in perspective, Feb '83 is the lowest ranked cat 4 on the NESIS list. I think there is very little chance this gets rated that high. The area of 20"+ in this system will prevent it from coming close to a cat 4 I would think. Low end 3 is still my guess.

but i think it needs to be higher than feb 4-7 2010

[A-L-E-X]

alex- march 60 is the 3rd highest rated storm of all time...8.77...not happening...maybe you mean march 58?

No I wouldnt rank this a four, but somewhere among the threes. I got an explanation for what I was looking for (and what I found as a similarity with this storm)-- which was why is March 1960 ranked so highly when it had a small area of very heavy snow like this one did? The answer was because it had a very large area of 4" snows. Personally, I consider those areas on the fringe of the storm.

[A-L-E-X]

but i think it needs to be higher than feb 4-7 2010

Im hoping we're not biased because we got screwed over majorly in that storm-- that storm did have a much larger area of very heavy snow. As far as being "rarer"-- thats much harder to argue, as a snowstorm of this kind of intensity and wind heavily impacting three of the major I-95 cities in a mod la nina is almost unprecedented.

[Analog96]

No I wouldnt rank this a four, but somewhere among the threes. I got an explanation for what I was looking for (and what I found as a similarity with this storm)-- which was why is March 1960 ranked so highly when it had a small area of very heavy snow like this one did? The answer was because it had a very large area of 4" snows. Personally, I consider those areas on the fringe of the storm.

I don't know if I agree with everything on the NESIS scale. Something needs to be said for total storm impact. 4"? 4" is not a big deal in the DCA-BOS corridor. 4" in Atlanta is a big deal, but you get my idea.

[A-L-E-X]

I don't know if I agree with everything on the NESIS scale. Something needs to be said for total storm impact. 4"? 4" is not a big deal in the DCA-BOS corridor. 4" in Atlanta is a big deal, but you get my idea.

Yeah, thats why I said "fringe." Im also considering the fact that for some areas, 4 inches is a huge deal-- but for us, I would make 6" the cut off and emphasize 10" and more.

[ORH_wxman]

but i think it needs to be higher than feb 4-7 2010

Why? That storm hammered a larger area.

[A-L-E-X]

Why? That storm hammered a larger area.

Will, how much was the difference in terms of population affected by heavy snow?

I still think we need a scale based on meteorological science, similar to the SS and the EF scales that also takes into account wind and storm intensity. Like I said earlier, on this scale, Andrew might have been a Cat 1 or 2.

[ORH_wxman]

Will, how much was the difference in terms of population affected by heavy snow?

I still think we need a scale based on meteorological science, similar to the SS and the EF scales that also takes into account wind and storm intensity. Like I said earlier, on this scale, Andrew might have been a Cat 1 or 2.

I'm not sure, but I'll bet the population was higher in the Feb 5-6 storm as it crushed all of the DC/BWI/PHL metro regions vs this one getting NYC metro and then BOS metro....PHL got both systems but Feb 5-6 was much much heavier there. The Feb '10 storm also hammered a lot of areas W of I-95 versus this past storm which lightened up very quickly W of 95.

The parameters of the scale is a totally different argument versus what this storm should actually be ranked on the current NESIS scale.

[A-L-E-X]

I'm not sure, but I'll bet the population was higher in the Feb 5-6 storm as it crushed all of the DC/BWI/PHL metro regions vs this one getting NYC metro and then BOS metro....PHL got both systems but Feb 5-6 was much much heavier there. The Feb '10 storm also hammered a lot of areas W of I-95 versus this past storm which lightened up very quickly W of 95.

The parameters of the scale is a totally different argument versus what this storm should actually be ranked on the current NESIS scale.

Yes, this is why I said earlier that if you base it on areal coverage the Feb storm was bigger. Actually both Feb storms were bigger. Now the December storm is a closer call (it was ranked as a 2.99 I believe.)

I think the scale is very useful for what its supposed to do; I dont think you can rank storms (for impact) the same way you can hurricanes and tornadoes. But I would still love to see something that ranks them meteorologically, just to have something to compare to the other scales.

Actually, the intensity of this thing is probably what kept it lower on the scale, as higher intensity is what leads to banding of precip-- a weaker, overrunning system, would have ranked higher.

[Paweatherguy1]

I'm not sure, but I'll bet the population was higher in the Feb 5-6 storm as it crushed all of the DC/BWI/PHL metro regions vs this one getting NYC metro and then BOS metro....PHL got both systems but Feb 5-6 was much much heavier there. The Feb '10 storm also hammered a lot of areas W of I-95 versus this past storm which lightened up very quickly W of 95.

The parameters of the scale is a totally different argument versus what this storm should

actually be ranked on the current NESIS scale.

Feb 10 had two foot snows back into Pittsburgh metro and 10 inch snows into Columbus... Much larger cove.

[MJW155]

Will, how much was the difference in terms of population affected by heavy snow?

I still think we need a scale based on meteorological science, similar to the SS and the EF scales that also takes into account wind and storm intensity. Like I said earlier, on this scale, Andrew might have been a Cat 1 or 2.

If you take population into account, wouldn't that mean a random 4-8 inch storm in 100 years could get a higher rating than this past blizzard based on the fact that the US population is always increasing? That doesn't sound right.

Let's say this past blizzard gets a rating of 3.0. Does that mean 10 years ago it would be a 2.8? What about 50 years ago? A 2.0?

What about 50 years from now? Will it get a 4.0?

[A-L-E-X]

If you take population into account, wouldn't that mean a random 4-8 inch storm in 100 years could get a higher rating than this past blizzard based on the fact that the US population is always increasing? That doesn't sound right.

Let's say this past blizzard gets a rating of 3.0. Does that mean 10 years ago it would be a 2.8? What about 50 years ago? A 2.0?

What about 50 years from now? Will it get a 4.0?

I hope theyre adjusting it to the population increase lol-- perhaps by using a proportional formula of the ratio of people affected to total population. It's still a pretty subjective scale.

[WeatherNC]

In any case, due to the fact there was snow from Alabama to Maine, a large area in the southern states of 4-10 inches, including Northern Georgia, North Carolina, and even higher amounts in western NC....as well as the very large hit given to southern VA...well, if that 69 storm is a 2, then this storm is at least a 3.

NC's take on the event...

Mid-level 3 from what I can see, but does the NESIS take into account only pop centers north of the NC/VA boarder; if so, the skip of the greater MA will likely bust it down to a 2?

[A-L-E-X]

Isnt there a formula for figuring this out? If so, we should be able to do that ourselves. However, I remember reading that the "solution" depends on which source you get your snowfall data from.

[gymengineer]

Yes, this is why I said earlier that if you base it on areal coverage the Feb storm was bigger. Actually both Feb storms were bigger. Now the December storm is a closer call (it was ranked as a 2.99 I believe.)

I think the scale is very useful for what its supposed to do; I dont think you can rank storms (for impact) the same way you can hurricanes and tornadoes. But I would still love to see something that ranks them meteorologically, just to have something to compare to the other scales.

Actually, the intensity of this thing is probably what kept it lower on the scale, as higher intensity is what leads to banding of precip-- a weaker, overrunning system, would have ranked higher.

KU describe two such scales that ranks them according to meteorological factors on page 1-2 of their paper about NESIS:

http://www.ncdc.noaa...n-uccellini.pdf

Since these two other scales focused on meteorology, neither of them needed to include the impact on the US-- the Great Atlantic Low and a Canadian blizzard rank the highest on these scales respectively.

The type of scale that you are describing has to include some impact. Otherwise, you could just rank the storms yourself by using whatever criteria you want-- lowest pressure, pressure difference, wind gust, etc.

[A-L-E-X]

KU describe two such scales that ranks them according to meteorological factors on page 1-2 of their paper about NESIS:

http://www.ncdc.noaa...n-uccellini.pdf

Since these two other scales focused on meteorology, neither of them needed to include the impact on the US-- the Great Atlantic Low and a Canadian blizzard rank the highest on these scales respectively.

The type of scale that you are describing has to include some impact. Otherwise, you could just rank the storms yourself by using whatever criteria you want-- lowest pressure, pressure difference, wind gust, etc.

Yeah, I agree-- its actually too complicated of an issue to just rank them by one criteria like that. Especially since lowest pressure isnt linked to total snowfall or areal coverage of heavy snow. Slow moving "weak" over-running systems that throw Pacific moisture over a dome of dense Arctic air probably have more impact and range. I actually think lower pressure might be negatively correlated with areal coverage of heavy snow, because in these kinds of systems, banding of heavy snow is a common characteristic. Thanks for the link to the paper-- I've always been jealous of Canadian Maritime residents for the kinds of storms they get. We talk about triple phasers like theyre a once in a generation thing, but up there, they get them much more frequently than we do. But as far as US systems go, for striking the right balance between intensity and coverage, I think pretty much any scale would rank March 1993 and January 1996 at the top.

[phil882]

NC's take on the event...

Mid-level 3 from what I can see, but does the NESIS take into account only pop centers north of the NC/VA boarder; if so, the skip of the greater MA will likely bust it down to a 2?

The folks that do the NESIS scale at NCDC are actually working on regional snowstorm category rankings, so that each area of the country will have its own impact scale... meaning the SE might have different top events, while the NE will have its own list.

I believe NESIS currently does take into account southeastern states area and population where the storm affected the area in its algorithm, but these numbers are then divided by the mean area and population values of the top 40 storms that have affected the 13 states in the Northeast. Thus the algorithm is calibrated for NE US...

This paper might help explain things more throughly.

http://www.ncdc.noaa.gov/snow-and-ice/docs/squires.pdf