32-Year Winter Storm Archive Complete

[Ginx snewx]

18 minutes ago, IrishRob17 said:

You mentioned "it was the 24 hour method"? How are you measuring these days, do you clear the board ever 6 hours? It's the constant debate whether we should clear every 6 or 24 hours and in the last NWS guidance @NorthShoreWx and I have found the 6 hour method is out for hobbiests like ourselves. 

Every 6

[NorthShoreWx]

5 hours ago, Ginx snewx said:

Totally under measured as it was the 24 hr method.

It's not technically an under-measurement if the observer is following the standard that they are supposed to.  The problem is that there are different standards for different types of observers.  I'll never beat ISP in a big storm unless they rain and I don't because they are supposed to wipe the board every 6 hours and I am not.  In the most recent storm, ISP reported 13.2" and I had 11.4".  I don't think they had more snow than I did (plus we snowed heavily a little longer before changeover to sleet), but both measurements can be technically correct.

I suspect the once in 24 hours max depth standard might be designed to make it easier for observers, plus in some instances (not all) it is a more accurate way to portray the snowfall.  Wiping the board more often makes sense for airports because it relates more directly to wiping the snow from runways.  It is frustrating that we can't do apples to apples comparisons, especially when doing projects like The 4 Seasons is doing.

For my money, snow depth and LE of the snowpack are the best way to compare between sites.

[CoastalWx]

@The 4 Seasons 

 

[IrishRob17]

21 minutes ago, NorthShoreWx said:

It's not technically an under-measurement if the observer is following the standard that they are supposed too.  The problem is that there are different standards for different types of observers.  I'll never beat ISP in a big storm unless they rain and I don't because they are supposed to wipe the board every 6 hours and I am not.  In the most recent storm, ISP reported 13.2" and I had 11.4".  I don't think they had more snow than I did (plus we snowed heavily a little longer before changeover to sleet), but both measurements can be technically correct.

I suspect the once in 24 hours max depth standard might be designed to make it easier for observers, plus in some instances (not all) it is a more accurate way to portray the snowfall.  Wiping the board more often makes sense for airports because it relates more directly to wiping the snow from runways.  It is frustrating that we can't do apples to apples comparisons, especially when doing projects like The 4 Seasons is doing.

For my money, snow depth and LE of the snowpack are the best way to compare between sites.

If I did the every 6 hours thing my 38.5" YTD would be closer to 50".

[Ginx snewx]

2 minutes ago, IrishRob17 said:

If I did the every 6 hours thing my 38.5" YTD would be closer to 50".

Do you want to measure the amount of snow that fell or just compacted snow. 24 hrs with say a 8 hrs snow event.  I measure 6 and then 2. The next day after either melting or drying out your measure could for arguments sake be 5 inches. That's what often happened in the record book. So how much snow actually fell . I say 8

[IrishRob17]

21 minutes ago, Ginx snewx said:

Do you want to measure the amount of snow that fell or just compacted snow. 24 hrs with say a 8 hrs snow event.  I measure 6 and then 2. The next day after either melting or drying out your measure could for arguments sake be 5 inches. That's what often happened in the record book. So how much snow actually fell . I say 8

Agreed, if one waits hours after its done to measure its going to be off. You always measure at the end of the event, so in that case I measure after 8 hours because the storm is over. You also need to measure at the point there's a change in precipitation type. I'm a snowpack guy anyway so what truly matters to me is what is at the stake each day. 

[Ginx snewx]

29 minutes ago, IrishRob17 said:

Agreed, if one waits hours after its done to measure its going to be off. You always measure at the end of the event, so in that case I measure after 8 hours because the storm is over. You also need to measure at the point there's a change in precipitation type. I'm a snowpack guy anyway so what truly matters to me is what is at the stake each day. 

Excellent 

[dendrite]

36 minutes ago, IrishRob17 said:

Agreed, if one waits hours after its done to measure its going to be off. You always measure at the end of the event, so in that case I measure after 8 hours because the storm is over. You also need to measure at the point there's a change in precipitation type. I'm a snowpack guy anyway so what truly matters to me is what is at the stake each day. 

Clearing every 6hrs is a nice interval so that places that get a lot of high ratio snow…like upslope areas and LES..don’t get penalized by compaction.

Take BUF in late Dec 2001.

24th
starting 6z depth 0”
New snow 20.5”
ending 5z depth 18” (+18”)

25th
5z depth 18”
new snow 4.9”
ending 0z depth 18” (0”)

26th
12z depth 18”
new snow 8.0”
6z depth 25” (+7”)

27th
6z depth 25”
new snow 21.9”
6z depth 33” (+8”)

28th
6z depth 33”
new snow 26.2”
20z depth 44” (+11”)
0z depth 41” (or +8”)
12z depth 38” (or +5”)

That’s 48.1” in the final 2 days with only 13” to 19” depth gain depending on when you caught the last depth measurement.

Imagine it snowing hard enough to produce 26” new with 6 hourly clearings, but it only goes in the books as 5” the next morning because of compaction? 

[IrishRob17]

4 hours ago, dendrite said:

Clearing every 6hrs is a nice interval so that places that get a lot of high ratio snow…like upslope areas and LES..don’t get penalized by compaction.

Take BUF in late Dec 2001.

24th
starting 6z depth 0”
New snow 20.5”
ending 5z depth 18” (+18”)

25th
5z depth 18”
new snow 4.9”
ending 0z depth 18” (0”)

26th
12z depth 18”
new snow 8.0”
6z depth 25” (+7”)

27th
6z depth 25”
new snow 21.9”
6z depth 33” (+8”)

28th
6z depth 33”
new snow 26.2”
20z depth 44” (+11”)
0z depth 41” (or +8”)
12z depth 38” (or +5”)

That’s 48.1” in the final 2 days with only 13” to 19” depth gain depending on when you caught the last depth measurement.

Imagine it snowing hard enough to produce 26” new with 6 hourly clearings, but it only goes in the books as 5” the next morning because of compaction? 

This is always an interesting discussion, do you clear every 6 hours?

[dendrite]

4 hours ago, IrishRob17 said:

This is always an interesting discussion, do you clear every 6 hours?

Always? No. I try to, but sometimes I go 8 or 12. I will extend it sometimes so that I can clear at midnight to get a daily snow and liquid amount.

[CPcantmeasuresnow]

1 hour ago, IrishRob17 said:

Agreed, if one waits hours after its done to measure its going to be off. You always measure at the end of the event, so in that case I measure after 8 hours because the storm is over. You also need to measure at the point there's a change in precipitation type. I'm a snowpack guy anyway so what truly matters to me is what is at the stake each day. 

The one difference I would note and I'll use the last storm as an example. When I cleared the board at 10pm I recorded 15.8 inches depth as the snow had ended. The next morning there was another 0.5 so I added that for a storm total of 16.3. I'm sure if I measured depth that morning it was probably closer to a 15 inch depth. 

[NorthShoreWx]

2 hours ago, Ginx snewx said:

Do you want to measure the amount of snow that fell or just compacted snow. 24 hrs with say a 8 hrs snow event.  I measure 6 and then 2. The next day after either melting or drying out your measure could for arguments sake be 5 inches. That's what often happened in the record book. So how much snow actually fell . I say 8

For the 24 hour measurements, the snowboard is only wiped once per day, but the greatest depth during that period is recorded as the snowfall.  If the snow on the board reaches a depth of 8" and then settles to 5", the amount of snowfall reported is 8"

I am not philosophically opposed to measuring and clearing the board every 6 or 12 hours, but the problem is that there are multiple prescribed standards which give rise to discussions like this.  I don't think there are any easy answers. 

[The 4 Seasons]

7 hours ago, CoastalWx said:

Yeah they had over 2’ for sure. I saw pics. We also had about 2’ in marshfield. I would pull that link shading right down to Plymouth and just south of Taunton. 

Ok what about the 18 in Hanson and Scituate? Scituate says it's final and Hanson is 1240pm.

[The 4 Seasons]

8 hours ago, dendrite said:

I’d toss Brockton. They had 14.0” listed in new snow on 3/31 but nothing after that. On the April form they had no new snow listed and only reported depth. The depth for 4/1 was 18”. They had 0” going into the storm. So there’s data that doesn’t jive. 

Yeah you're right going back and looking at the COOP data it does say "miss 1" i must have missed that.  I've estimated that I've plotted about a quarter million data points so it's easy to make a few mistakes -ha

[Chrisrotary12]

29 minutes ago, The 4 Seasons said:

Yeah you're right going back and looking at the COOP data it does say "miss 1" i must have missed that.  I've estimated that I've plotted about a quarter million data points so it's easy to make a few mistakes -ha

I greatly appreciate your work. I made a comment to @40/70 Benchmark in a storm thread about whether we'd rather have a Pats Superbowl or 2' of snow. I quipped something the effect of: "I've seen 6 superbowls, not sure I have 6 2' snowstorms."

Which got me to thinking about what my top 10 snow events are. So I used your archive to build my list. Based on this... turns out I have 5 2' snowstorms. And the top 10 starts at 20".

[The 4 Seasons]

Just now, Chrisrotary12 said:

I greatly appreciate your work. I made a comment to @40/70 Benchmark in a storm thread about whether we'd rather have a Pats Superbowl or 2' of snow. I quipped something the effect of: "I've seen 6 superbowls, not sure I have 6 2' snowstorms."

Which got me to thinking about what my top 10 snow events are. So I used your archive to build my list. Based on this... turns out I have 5 2' snowstorms. And the top 10 starts at 20".

for where? Nashua? i only have SNE snowfall maps but most of those events do have northeast maps and NESIS if available. 

[CoastalWx]

2 hours ago, The 4 Seasons said:

Ok what about the 18 in Hanson and Scituate? Scituate says it's final and Hanson is 1240pm.

I’ll take the over on both. Hanson probably had close to 2’. 
Scituate depends where in town but anywhere away from water likely had close to 2’.

[The 4 Seasons]

4 minutes ago, CoastalWx said:

I’ll take the over on both. Hanson probably had close to 2’. 
Scituate depends where in town but anywhere away from water likely had close to 2’.

Got it. Anything else? You wanna take it look at it, im editing it now so i can change the lines, ill default to you guys since you are much more familiar with this storm, especially in that area. I don't even remember it. I am bringing the 20" line across like you mentioned. 

[The 4 Seasons]

I don't know how i missed BDL. I bet it was during the time that 1996-2003 was almost completely missing and they added it back i remember Wiz and I were talking about that. 

14.7 BDL

[Chrisrotary12]

1 hour ago, The 4 Seasons said:

for where? Nashua? i only have SNE snowfall maps but most of those events do have northeast maps and NESIS if available. 

 

[CoastalWx]

Yea that should work @The 4 Seasons Hingham did have 27” so makes me feel good about scituate which is fairly close by. Hanson is south but inland a bit. 

[CoastalWx]

15 minutes ago, Chrisrotary12 said:

 

Jan 2005 I think you meant?

[The 4 Seasons]

5 minutes ago, CoastalWx said:

Yea that should work @The 4 Seasons Hingham did have 27” so makes me feel good about scituate which is fairly close by. Hanson is south but inland a bit. 

27? I have 26 from the PNS where do you see 27? Hingham COOP is 23. Is that from someone you know from there