March 22-23 Storm Thread: Cabins and Pony-Os?

[40/70 Benchmark]

43 minutes ago, OSUmetstud said:

Thats a 5 day les storm. Lots of compaction. Look at the elma report from nov 2014. That was 57" depth after about 90-100" in 60 hours. 

Right...its amplified over a longer duration, but same idea.

[40/70 Benchmark]

The Kev-zone killed my forecast, along with the Hubbdave-fail...decent otherwise.

https://easternmassweather.blogspot.com/2019/03/3-213-22-verification.html

[J.Spin]

9 hours ago, MetHerb said:

They should be measuring at the end of a snowfall.

I’ve seen this approach mentioned before, and it’s good if you can do it, but it’s not going to make a good hard and fast rule because it can be really impractical in very snowy climates.  Up here in the Northern Greens (as in many mountainous areas around the country), “days and days of snow” isn’t just one of DIT’s bleary bromides used for trolling, it’s a climatological reality.  PF frequently mentions the “snow globe” up here, and indeed it can snow for days and days with no real stop as one small system affecting the area blends into the next, or a stacked low pressure system sits up in the Maritimes and pinwheels moisture in for days on end.  Using timed intervals for snow measurement and snowboard clearing is much more appropriate.

[CoastalWx]

While I appreciate those who make the effort of trying to measure correctly and properly including myself, overall snow measuring is a joke. Nobody really knows how to do it, reports are submitted and then broadcasted that are clearly incorrect, and we don't even have a homogeneous method (see first order stations vs the coops). It's a joke. It's the worst metric we have in weather. 

[40/70 Benchmark]

1 hour ago, CoastalWx said:

While I appreciate those who make the effort of trying to measure correctly and properly including myself, overall snow measuring is a joke. Nobody really knows how to do it, reports are submitted and then broadcasted that are clearly incorrect, and we don't even have a homogeneous method (see first order stations vs the coops). It's a joke. It's the worst metric we have in weather. 

That is the issue...pick one.

[CoastalWx]

8 minutes ago, 40/70 Benchmark said:

That is the issue...pick one.

I usually try to do the 6 hr or close to it, method. 

[40/70 Benchmark]

1 minute ago, CoastalWx said:

I usually try to do the 6 hr or close to it, method. 

Yea, same...happy medium. Apparently some don't realize how that can sometimes cause a large discrepancy from the depth measurement.

[tamarack]

14 hours ago, dendrite said:

idk if they’re as concerned about comparing different sites as much as they are keeping the same measuring methods for sites over the historical data period. The COOPs have been measuring only at 6-8am for a long time because they’re just volunteers that have other jobs and responsibilities too. The LCDs have historically had paid observers measuring hourly at the airports for many decades now. So they are keeping the 6hr measuring there to keep the methodology continuous. 

I’ve always thought 6-8 hours was a happy middle ground for allowing some compaction, but not letting it sit too long. I’ve always mimicked CON with my observing methods so I’ve stuck to 6hrs when I can. But part of me wishes I started at 8hrs so I could measure, go to bed, sleep 7.5hrs, and then wake up to an on-time measurement rather than setting my alarm for 11z after measuring at 5z. lol

My protocol on long duration events is sort of like an 8-hour schedule.  I've done obs at 9 PM since moving to N. Maine in 1976, and my entry into cocorahs in 2009 added the 7 AM obs.  On an extended daytime event (and if I'm home), I'll take a core then clear the board at 2 PM, the halfway point between the other 2 obs.  Even before cocorahs, I'd usually do the morning obs for precip.  Another note:  As the instructions direct, I record the peak depth of a snowfall event whenever it occurs, but report total pack depth only at the specified intervals, 7A for cocorahs and 9P for personal records.  My deepest pack here came at the 9P obs on 2/23/2009 with 49" at the stake.  When accumulating snow had ended about 11A, depth was 51" (result of a 24.5" dump atop glacial 27" pack) but that's just a memory trivia, because it wasn't at the regular obs time.

[Cold Miser]

White Out rides again!  The guy I gave my snow blower to last week lives in Tolland so it was able to get one more run this season with his new owner.   He picked  up over 8" Saturday morning (he said 10" but I don't think he go that much), but by the time he got to it in the early afternoon most was melted.  ...I think he just wanted to test the ole' guy out.  I shed a small tear when I saw these photos and the video.


 

[dendrite]

Was it the same feeling you got when watching another guy touch your girl?

[CapturedNature]

14 hours ago, J.Spin said:

I’ve seen this approach mentioned before, and it’s good if you can do it, but it’s not going to make a good hard and fast rule because it can be really impractical in very snowy climates.  Up here in the Northern Greens (as in many mountainous areas around the country), “days and days of snow” isn’t just one of DIT’s bleary bromides used for trolling, it’s a climatological reality.  PF frequently mentions the “snow globe” up here, and indeed it can snow for days and days with no real stop as one small system affecting the area blends into the next, or a stacked low pressure system sits up in the Maritimes and pinwheels moisture in for days on end.  Using timed intervals for snow measurement and snowboard clearing is much more appropriate.

I very much appreciate that a rule that applies for 90% of the country isn't going to work well in certain places, particularly like yours.  Having said that, I've also had events that span several days and with no clear break in the snowfall.  In those cases I kept my record consistent by only clearing the board at my 7AM observation.  I've also had events where it will snow for several hours, stop, snow some more, stop and then snow again.  I use the standard that the board is cleared after each of those and each of those are added up for a total snow fall over the past 24 hours.  That happened on Friday and Saturday.  I had 1" of snow around noon on Friday and picked up 5.5" overnight for a 24 hour total of 6.5".

You have to pick what works for your location and what you feel accurately reflects what fell and then stick to it.  I've always objected to the fact that NWS changed the long standing standard in the 90s.  Before then, I don't remember too much debate, except to question if someone was measuring a drift or something.

[OceanStWx]

On 3/24/2019 at 6:21 PM, powderfreak said:

It definitely can make a large difference up this way.  Probably the same in lake effect.

In high ratio snow if you're only measuring once, it's going to compact and possibly be several inches. But if you're super concerned with compaction, you can go out and measure the snow before the most significant compaction happens. You're only tied to clearing the board at observation time. 

On 3/25/2019 at 12:33 AM, 40/70 Benchmark said:

That is the issue...pick one.

See that's my point. You say be consistent, but then I tell people 24 hours is the most consistent and people aren't happy. If we're going to pick one it's going to be 24 hours because that's what the vast majority of reporting stations use (at least official NWS sources). But nobody wants to do 24 hours because it's less snow. There will never be a way to sync up all snowfall reports. We have to rely on volunteers, so the best you can hope for is every 8 hours after someone gets some sleep, but there's no way we can require that.

The reality is that the more important measurements when it comes to snowfall are the liquid equivalent (for snow load and meltwater purposes) and snow depth because that's what's left on the ground after a storm. The climatological significance of the snowfall measurement is basically nil. 

On 3/25/2019 at 1:51 PM, MetHerb said:

I very much appreciate that a rule that applies for 90% of the country isn't going to work well in certain places, particularly like yours.  Having said that, I've also had events that span several days and with no clear break in the snowfall.  In those cases I kept my record consistent by only clearing the board at my 7AM observation.  I've also had events where it will snow for several hours, stop, snow some more, stop and then snow again.  I use the standard that the board is cleared after each of those and each of those are added up for a total snow fall over the past 24 hours.  That happened on Friday and Saturday.  I had 1" of snow around noon on Friday and picked up 5.5" overnight for a 24 hour total of 6.5".

You have to pick what works for your location and what you feel accurately reflects what fell and then stick to it.  I've always objected to the fact that NWS changed the long standing standard in the 90s.  Before then, I don't remember too much debate, except to question if someone was measuring a drift or something.

I'm not sure if you're referring to the fact that in 1996 the NWS actually expanded the option for coops to do 6 hourly measurements. Before that time it was always once a day. Manned stations were always 6 hourly however. 

So I guess the actual inconsistency is that the NWS ever decided to allow volunteers to do 6 hourly measurements.

[J.Spin]

9 hours ago, OceanStWx said:

Manned stations were always 6 hourly however. 

That’s always been the thing for me.  If the 6-hour snow clearing interval methodology is used at the manned, 1^st order, best of the best (with honors), gold standard stations, then it must be desirable with respect to data collection and representation of the local climate, right?  Surely these stations can’t be doing this because the 6-hour interval data are less desirable than the 24-hour interval data?  It’s hard to imagine the NWS sitting around discussing things like “Hey, you know, we’ve got this continual budget surplus and our employees are always complaining about how they’re looking for things to do.  I’ve got a radical idea.  We could probably burn down some of this money and give them some busy work if instead of simply clearing snowboards once a day, we cleared them four times a day!  It’s not the data we want, it’s actually less desirable than what we get form the once-a-day clearings, but I think everyone in the organization is willing to make the sacrifice if it means getting rid of this extra money.”

I just don’t think that’s how it all went down.

Yes, from the “weenie” perspective, the more frequent clearings inflate snowfall numbers.  From years of collecting data in the upslope zone of the Northern Greens though, there’s no doubt from my perspective that capturing data from these intermediate clearings is a better representation of the local climate.

It is possible to have a global standard across all agencies if the standard is simply “measure and clear once a day, or as frequently as six-hour intervals”.  This is essentially the impression I got from my local CoCoRaHS coordinator, and pretty much how the instructions were written.  If you can do six-hour (or eight-hour, or twelve hour clearings), great, you’ll get a representation of your local climate that is more equivalent to a 1^st-order station.  If not, that’s fine as well, your site is below the priority of a 1^st order station anyway, and at least we’re getting some data from you.

But I also agree that liquid equivalent trumps it all anyway.  Get that liquid equivalent as part of your workup and you’re set regardless of the collection interval.

[CapturedNature]

13 hours ago, OceanStWx said:

I'm not sure if you're referring to the fact that in 1996 the NWS actually expanded the option for coops to do 6 hourly measurements. Before that time it was always once a day. Manned stations were always 6 hourly however. 

So I guess the actual inconsistency is that the NWS ever decided to allow volunteers to do 6 hourly measurements.

I think it was in 1995.  This wasn't a change to coop standards but at first order stations.  I left the weather business just prior to that and wasn't "up to date" on the latest changes at the time the Philadelphia airport set a record in January 1996.  It blew their previous record out of the water as well as other anomalies when comparing to surrounding stations.  I remember discussing it with other meteorologist friends at the time who were still in the business and they told me about the change to sweeping and measuring every 6 hours.  We all thought it was bunk because it was a new practice.  Are you saying that different airports would measure differently prior to that and that the 6 hour measurements were done all along?  I just don't recall that topic coming up prior to that and it was such a big jump from the previous record and there have been so many records broken since then.

[40/70 Benchmark]

17 hours ago, OceanStWx said:

In high ratio snow if you're only measuring once, it's going to compact and possibly be several inches. But if you're super concerned with compaction, you can go out and measure the snow before the most significant compaction happens. You're only tied to clearing the board at observation time. 

See that's my point. You say be consistent, but then I tell people 24 hours is the most consistent and people aren't happy. If we're going to pick one it's going to be 24 hours because that's what the vast majority of reporting stations use (at least official NWS sources). But nobody wants to do 24 hours because it's less snow. There will never be a way to sync up all snowfall reports. We have to rely on volunteers, so the best you can hope for is every 8 hours after someone gets some sleep, but there's no way we can require that.

The reality is that the more important measurements when it comes to snowfall are the liquid equivalent (for snow load and meltwater purposes) and snow depth because that's what's left on the ground after a storm. The climatological significance of the snowfall measurement is basically nil. 

I'm not sure if you're referring to the fact that in 1996 the NWS actually expanded the option for coops to do 6 hourly measurements. Before that time it was always once a day. Manned stations were always 6 hourly however. 

So I guess the actual inconsistency is that the NWS ever decided to allow volunteers to do 6 hourly measurements.

I don't like 24 hours because it isn't accurate. How are you going to get an accurate snowfall measurement once per day? Just as bad as swiping every hour in the other direction. Peak storm depth? Okay.

To be perfectly honest, I pick whatever the paid LCD observers do. If that isn't the best method, then change it.

The climatological significane of snow measuring is not at all nil if you want to compare apples to apples among sites. I completely disagree with you.