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NESIS rating? Boxing Day Blizzard

09-10 analogy

please try to be objective   

230 members have voted

  1. 1. what NESIS rating will the Dec 25-27 snowstorm eventually receive

    • 5 (10.0+)
      9
    • high 4 (8.0 to 9.99)
      24
    • low 4 (6.0 to 7.99)
      57
    • high 3 (5.0 to 5.99)
      78
    • low 3 (4.0 to 4.99)
      49
    • 2 or below
      13

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A-L-E-X

A-L-E-X

Posted
Posted

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...ocs/squires.pdf

Well, I hope the scale gets modified one day to include intensity and wind in some respect and to ditch the 4" qualifiers, which are meaningless in the NE

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A-L-E-X

A-L-E-X

Posted
Posted

Forky told me 30.

He might have gotten 30 lol-- there was a small corridor of 30-32 from like Ocean County NJ up to NE NJ.... I wonder why that isnt shown in those maps? There was also an area of 24-29 inches from Staten Island to Brooklyn, as well as an area of 20-24 inches in parts of southern and western Nassau. The NWS OKX map depicts all of this; why is the above map different? It would have been a 3 regardless, but it probably would have been a high end 3 if the higher amounts were included (especially since they occurred in densely populated areas.)

Either way, looks like this got ranked higher than any of the storms from last winter and was 0.08 away from being a high end Cat 3 (would have been if any of the 30 inch amts were included lol.)

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earthlight

earthlight

Posted
Posted

Doesn't look as impressive as some other ones, but I guess it has a lot of coverage.

MIssed the 20"+ amounts in Brooklyn and Queens and the 30"+ amounts in NJ.

Yeah I don't understand how those are just excluded from the map

...UNION COUNTY...

RAHWAY 32.0 1000 AM 12/27 PUBLIC

ELIZABETH 31.8 700 AM 12/27 TRAINED SPOTTER

...KINGS COUNTY...

BROOKLYN 24.5 800 AM 12/27 PUBLIC

MARINE PARK 24.5 800 AM 12/27 PUBLIC

SHEEPSHEAD BAY 24.0 700 AM 12/27 TRAINED SPOTTER

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A-L-E-X

A-L-E-X

Posted
Posted

Yeah I don't understand how those are just excluded from the map

...UNION COUNTY...

RAHWAY 32.0 1000 AM 12/27 PUBLIC

ELIZABETH 31.8 700 AM 12/27 TRAINED SPOTTER

...KINGS COUNTY...

BROOKLYN 24.5 800 AM 12/27 PUBLIC

MARINE PARK 24.5 800 AM 12/27 PUBLIC

SHEEPSHEAD BAY 24.0 700 AM 12/27 TRAINED SPOTTER

Since it says preliminary, do you think they will be added in later?

BTW that area of 30 plus also extends down to parts of central Jersey (Belmar, Toms River, etc.) and close to 30 over most of Staten Island and over 20 on parts of Nassau, with many of these measurements taken by trained spotters.

High end 3.....

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OSUmetstud

OSUmetstud

Posted
Posted

Yeah I don't understand how those are just excluded from the map

...UNION COUNTY...

RAHWAY 32.0 1000 AM 12/27 PUBLIC

ELIZABETH 31.8 700 AM 12/27 TRAINED SPOTTER

...KINGS COUNTY...

BROOKLYN 24.5 800 AM 12/27 PUBLIC

MARINE PARK 24.5 800 AM 12/27 PUBLIC

SHEEPSHEAD BAY 24.0 700 AM 12/27 TRAINED SPOTTER

i thought NCDC only did first order stations...public and trained spotter reports are not included.

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Paweatherguy1

Paweatherguy1

Posted
Posted

Yeah I don't understand how those are just excluded from the map

...UNION COUNTY...

RAHWAY 32.0 1000 AM 12/27 PUBLIC

ELIZABETH 31.8 700 AM 12/27 TRAINED SPOTTER

...KINGS COUNTY...

BROOKLYN 24.5 800 AM 12/27 PUBLIC

MARINE PARK 24.5 800 AM 12/27 PUBLIC

SHEEPSHEAD BAY 24.0 700 AM 12/27 TRAINED SPOTTER

It seems to be an issue with filling in some higher areas in certain cases.

I know on Feb 5-6, that basically the entire Pittsburgh Metro area saw 20-25 inches of snow, at the very least a large portion of SW PA did...that is not reflected on the map of that storm at all.

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gymengineer

gymengineer

Posted
Posted

It was stated earlier in this thread--- these NCDC maps never make people 'happy' because they only take into account first order and COOP reports (for pretty obvious reasons, since the NCDC itself doesn't accept random spotter reports into its records).

There's consistency across all of these storms in leaving out the patches of higher amounts, so it's not like your favorite storm ended up short compared to the others. If you want maps that look more like what you expect from spotter reports, you have to hope the KU are making their own for a new volume of Northeast Snowstorms, because I doubt the NCDC will change their methodology. One of the most extreme examples is this, as anyone from NE can tell what's "wrong" with this map:

19970331-19970401-2.29.jpg

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RU848789

RU848789

Posted
Posted

Doesn't look as impressive as some other ones, but I guess it has a lot of coverage.

MIssed the 20"+ amounts in Brooklyn and Queens and the 30"+ amounts in NJ.

20101224-20101228-4.92-p.jpg

I have no problem with missing 30"+ amounts, as those were quite possibly outliers, since there were only a couple of locations that reported 30" or more, but I can't fathom how they missed so much of the >20" swath, which was way larger than indicated on this map. Much of Bergen, Essex, Hudson, Union, Middlesex, Monmouth, Ocean, Atlantic and Cape May Counties in NJ and NYC and the lower Hudson Valley all had >20" amounts and most of that is missing from this map (and that's a high population density swath that clearly would've made this a high end 3 at least). WABC in NYC (Channel 7) had a real nice map of this.

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A-L-E-X

A-L-E-X

Posted
Posted

I have no problem with missing 30"+ amounts, as those were quite possibly outliers, since there were only a couple of locations that reported 30" or more, but I can't fathom how they missed so much of the >20" swath, which was way larger than indicated on this map. Much of Bergen, Essex, Hudson, Union, Middlesex, Monmouth, Ocean, Atlantic and Cape May Counties in NJ and NYC and the lower Hudson Valley all had >20" amounts and most of that is missing from this map (and that's a high population density swath that clearly would've made this a high end 3 at least). WABC in NYC (Channel 7) had a real nice map of this.

I wonder how many of those official reporting stations are actually located in the 20 plus zone. I know we have EWR and NYC (but it doesnt seem they have NYC under the dark blue coloring....hmmm) were there any other "official" 20 inch plus amounts? Do Teterboro, Caldwell, New Brunswick, Linden, Toms River, Belmar, Newburgh, White Plains, Montgomery, Poughkeepsie and Monticello all report snowfall?

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psuhoffman

psuhoffman

Posted
Posted

why are people so bent out of shape over this rating scale? You realize its flawed in that it ranks storms based on their impact on people not the actual severity of the storm. By that standard a 10" storm that hits NYC would be rated higher then a 30" storm that hits the mid atlantic because it affected less poeple, yet no one would argue that the 10" storm was more historic. This is subjective.

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ORH_wxman

ORH_wxman

Posted
Posted

I wonder how many of those official reporting stations are actually located in the 20 plus zone. I know we have EWR and NYC (but it doesnt seem they have NYC under the dark blue coloring....hmmm) were there any other "official" 20 inch plus amounts? Do Teterboro, Caldwell, New Brunswick, Linden, Toms River, Belmar, Newburgh, White Plains, Montgomery, Poughkeepsie and Monticello all report snowfall?

LGA and JFK reported well under 20" amounts so just because Central Park did, it doesn't mean they should shade the entire region under dark blue. They have to take into account all the measurements, not just the high ones.ORH recorded 12.7" but we aren't under the 10-20" shade. Lots of areas near here recorded like 8-10".

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A-L-E-X

A-L-E-X

Posted
Posted

LGA and JFK reported well under 20" amounts so just because Central Park did, it doesn't mean they should shade the entire region under dark blue. They have to take into account all the measurements, not just the high ones.ORH recorded 12.7" but we aren't under the 10-20" shade. Lots of areas near here recorded like 8-10".

Oh I agree, but I was thinking they would interpolate with the general idea that since Staten Island is closer to NJ they should have snowfall amounts between what EWR and NYC had and so should SW Brooklyn, but that might be asking too much-- that would be a micro fine adjustment to make on that kind of a map lol.

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LocoAko

LocoAko

Posted
Posted

I wonder how many of those official reporting stations are actually located in the 20 plus zone. I know we have EWR and NYC (but it doesnt seem they have NYC under the dark blue coloring....hmmm) were there any other "official" 20 inch plus amounts? Do Teterboro, Caldwell, New Brunswick, Linden, Toms River, Belmar, Newburgh, White Plains, Montgomery, Poughkeepsie and Monticello all report snowfall?

New Brunswick does, and came in with 19.5". I don't think Belmar has an official COOP station (They had a spotter report 31.0"). Teterboro doesn't do snow, and neither does Linden, Toms River, Belmar, Caldwell, or any of the NY stations listed.

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RU848789

RU848789

Posted
Posted

why are people so bent out of shape over this rating scale? You realize its flawed in that it ranks storms based on their impact on people not the actual severity of the storm. By that standard a 10" storm that hits NYC would be rated higher then a 30" storm that hits the mid atlantic because it affected less poeple, yet no one would argue that the 10" storm was more historic. This is subjective.

No, while the entire premise contains subjective elements in deciding what factors go into the NESIS ranking, the NESIS ranking, itself, is completely objective and data-driven.

My main point is that I think, in this case, there was a much more widespread snowfall of >20" in a highly populated area than is captured in the current map and this would have significantly increased the NESIS score if the true extent of the >20" accumulation area were captured. If you look at the public info reports from Philly/NYC, there are literally dozens of reports of >20" snowfalls (including at my house, where I do rigorous snowfall measurements and recorded 23"). I can understand only using measuring stations which ensure quality data, but it sounds like we only have a few of those in the NJ/NYC area, which is disappointing.

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RU848789

RU848789

Posted
Posted

Thought folks might find this interesting: this map from the NWS in Upton clearly shows much more widespread areas of snowfall greater than 20" relative to the NESIS map. One would think the criteria for data quality for the NWS map wouldn't be below (or at least not far below) that requred for NESIS, but I could be wrong. Anyway, this map is much closer to the Channel 7 map I mentioned the other day and I'm sure if this map were used the NESIS score would go up appreciably.

http://www.erh.noaa.gov/okx/StormEvents/storm12262010.html

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gymengineer

gymengineer

Posted
Posted

No, while the entire premise contains subjective elements in deciding what factors go into the NESIS ranking, the NESIS ranking, itself, is completely objective and data-driven.

My main point is that I think, in this case, there was a much more widespread snowfall of >20" in a highly populated area than is captured in the current map and this would have significantly increased the NESIS score if the true extent of the >20" accumulation area were captured. If you look at the public info reports from Philly/NYC, there are literally dozens of reports of >20" snowfalls (including at my house, where I do rigorous snowfall measurements and recorded 23"). I can understand only using measuring stations which ensure quality data, but it sounds like we only have a few of those in the NJ/NYC area, which is disappointing.

It's in every case that the maps are 'conservative.' Again, if you want them to change the map for this storm to look like other maps you've seen, every other storm's map will also need to change. I'm not sure the storms would be re-ordered much even if you were to complete that exercise since every storm's rating would increase.

As for what data is used, it's not a function of NESIS. It's that the NCDC is the agency currently using the scale. I suppose if the function ever got switched over local NWS offices, then the types of data they include might expand to spotter reports. But a climate agency is of course going to use stations in their climate records.

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Rick G

Rick G

Posted
Posted

To be fair, there is no perfect solution. How many times on Eastern (A moment of silence ) did we as a group complain about inflated storm totals? NWS may take storm totals from the general public but I can see why NCDC skips the spotter reported totals.

Anyway it is not perfect.

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