DCA Snowfall Total Controversy

[MN Transplant]

When possible, my parents still are doing 6-hourly too. Its all they've done. NWS HQ has "encouraged" all non-airport snow reporters (spotter and coop) to cease 6-hour measurements, though not all WFO's are on board.

But at the airports it should still be 6-hr measurements?

I don't necessarily have an issue with trying to standardize the measurements, but it ceases to be snowfall at that point and becomes new snow depth. I was particularly unimpressed with the suggestion that if it snows 3", then rains and melts it away, then snows 3 more inches, then the daily total would be 3".

[isohume]

When possible, my parents still are doing 6-hourly too.  Its all they've done.  NWS HQ has "encouraged" all non-airport snow reporters (spotter and coop) to cease 6-hour measurements, though not all WFO's are on board. 

 

[famartin]

But at the airports it should still be 6-hr measurements?

I don't necessarily have an issue with trying to standardize the measurements, but it ceases to be snowfall at that point and becomes new snow depth. I was particularly unimpressed with the suggestion that if it snows 3", then rains and melts it away, then snows 3 more inches, then the daily total would be 3".

I didn't say I liked the new standards.  Just that that's what they are.  I can live with volunteers not doing 6-hour measurements since people have lives and, as mentioned, over history most of them never did 6-hour measurements anyway.  That whole 3", then gone, then 3" more, but it only counts as 3" thing shocks me greatly. 

[famartin]

drumset-1.gif

All our spotter materials still refer to 6-hour measurements. 

[isohume]

All our spotter materials still refer to 6-hour measurements. 

 

Yeah same here and that's how we train our COOP observers. It's unrealistic to think they will go out and measure at 6 hr intervals tho. I was just referring to your pun. 

[famartin]

Yes, the evidence *HAS* to be overwhelming.  And its not, quite frankly.  I know you are invested in this storm being a higher rank than tied with Snowmageddon for some reason.  Isn't it good enough that its top 3 at your house?  Or whatever it is there?

 

As far as snowfall changes in the F6's... how do you know such changes were not due to data entry error?  Did you see a statement that said "data changed due to such and such"?  The one case I am aware of where a substantial edit was made was BWI in Snowmageddon, and in that case it was downgraded to the max depth because the observer was over-measuring.  So, I'm not sure what you are expecting with DCA.

 

You're invested in building a case against altering the record, and I am not entirely sure why.  Is this like a football challenge where we defer to the call on the field and the evidence has to be overwhelming?  Or is there some other standard that we are unaware of?  

 

I've been following snowfall data here religiously for 12 years now, and there have been a number of changes to preliminary totals for all 3 airports, and not just based on some data entry error, and not just moderate to major events.  I have a body of work here staunchly defending DCA's snow totals for most storms - - I can pull up the posts if needed - - especially the last 2 winters.  I am not gunning for anyone.  

 

IF, and someone in the know is free to correct the record if it needs to be corrected.  IF my understanding is correct, they had one snowboard, and it got buried in the snow at some point and they couldn't find it. So they had to improvise.  At 2:52 pm, 17" had fallen. I have video from 2:51 pm, and it is apocalyptic looking in downtown DC yet somehow only 0.8" fell the next 2 hours.  At 4:52 pm when it was still snowing hard, evidenced not only by the 4:52 OB, but also by the fact that 0.04" liquid was captured in the following hour (we know it is probably at least 0.06"), they measured 17.8", and quit measuring the storm.  So, just to be clear. They measured 17.8" at 4:52 PM - almost certainly a snow depth measurement - and finalized the total.  And then it snowed for another 7 hours.  Again.  If I am not getting the facts right, someone can please feel free to correct me.  I am not here to perpetuate something that isn't true or is misleading.

 

I hope the standard for correcting an error is nothing other than - let's do the best we can to get it right -  and not some "ruling on the field" standard.  If this is about not upsetting the FAA or not rocking the boat or not fracturing the relationship between LWX and the DC observers, then I think it is kind of a bummer. There are people in this forum who take measuring very seriously.  We have trained spotters who post here and Cocorahs folks and ACON folks, and skilled hobbyists.  Accuracy is a source of pride here.  Mapgirl has made professional maps the last 2 winters based on our reporting.  We are creating a body of work.  So, I'd hope folks who are the stewards of official historic records work their hardest to maintain the integrity of that record, if we are putting that much effort into an unofficial reference.  

 

If the FAA erred, so be it. Hopefully LWX will fix it if that is the case.  If it ends up being 17.8", so be it and it doesn't change the fact that LWX/FAA are still good people who do good work.  Agreeing to disagree is healthy. But it would be kind of a bummer if it is because some arbitrary standard got in the way of just trying to get it right.  

[famartin]

Yeah same here and that's how we train our COOP observers. It's unrealistic to think they will go out and measure at 6 hr intervals tho. I was just referring to your pun. 

Which is exactly the reason why HQ changed that part.  Which I also totally understand.

 

The other part about ignoring 3" that melted and then fell again... yeah, that's like "huh"?  I mean, if you didn't see it, you didn't see it, but ignoring it?

[winterymix]

The more I think about this, the more of a feeling I get that everything before the final report was tossed by the last observer during the storm. So, we can't say anything about comparisons to earlier measurements.

Considering that, there is evidence that supports the storm total as reported. (See earlier post if you are still having trouble with the history of fall va depth matching at DCA). At this point I feel that the odds it remains intact are decent.

In a sense, you speak for us at LWX.

Considering Deathband's scientific integrity, isn't it it I arguable that something must be added to the afternoon 17.8"?

The path of least regret could be @call it an inch" and revise to 18.8".

[isohume]

Which is exactly the reason why HQ changed that part.  Which I also totally understand.

 

The other part about ignoring 3" that melted... yeah, that like "huh"?

 

Yeah that's bizarre. Our OPL tried to explain it to us at our winter wx seminar, but couldn't. 

[winterymix]

Yes, the evidence *HAS* to be overwhelming.

Deathband is a better scientist for free than the FAA paid observers that don't care enough to measure properly.

[famartin]

In a sense, you speak for us at LWX.

Considering Deathband's scientific integrity, isn't it it I arguable that something must be added to the afternoon 17.8"?

The path of least regret could be @call it an inch" and revise to 18.8".

 

The question is whether it was actually 17.8" at the afternoon total.  Apparently the observer late in the day threw out all previous readings and started from scratch.  Which means the 17.8 was not correct yet.  Supposedly.

 

I'm not saying I *know* the 17.8 is right.  I'm saying simply that the evidence for changing it isn't solid.  The whole thing is definitely a mess.  Maybe it will get changed, I don't know.  The only thing I can say with certainty is that the snow depth they've reported in the last couple days is correct.

[winterymix]

The question is whether it was actually 17.8" at the afternoon total. Apparently the observer late in the day threw out all previous readings and started from scratch. Which means the 17.8 was not correct yet. Supposedly.

I'm not saying I *know* the 17.8 is right. I'm saying simply that the evidence for changing it isn't solid. The whole thing is definitely a mess. Maybe it will get changed, I don't know. The only thing I can say with certainty is that the snow depth they've reported in the last couple days is correct.

I'm glad you are at LWX, feel you have a really good attitude in your comments and so, please stay in these conversations.

[Scarlet Pimpernel]

You're invested in building a case against altering the record, and I am not entirely sure why.  Is this like a football challenge where we defer to the call on the field and the evidence has to be overwhelming?  Or is there some other standard that we are unaware of?  

 

I've been following snowfall data here religiously for 12 years now, and there have been a number of changes to preliminary totals for all 3 airports, and not just based on some data entry error, and not just moderate to major events.  I have a body of work here staunchly defending DCA's snow totals for most storms - - I can pull up the posts if needed - - especially the last 2 winters.  I am not gunning for anyone.  

 

IF, and someone in the know is free to correct the record if it needs to be corrected.  IF my understanding is correct, they had one snowboard, and it got buried in the snow at some point and they couldn't find it. So they had to improvise.  At 2:52 pm, 17" had fallen. I have video from 2:51 pm, and it is apocalyptic looking in downtown DC yet somehow only 0.8" fell the next 2 hours.  At 4:52 pm when it was still snowing hard, evidenced not only by the 4:52 OB, but also by the fact that 0.04" liquid was captured in the following hour (we know it is probably at least 0.06"), they measured 17.8", and quit measuring the storm.  So, just to be clear. They measured 17.8" at 4:52 PM - almost certainly a snow depth measurement - and finalized the total.  And then it snowed for another 7 hours.  Again.  If I am not getting the facts right, someone can please feel free to correct me.  I am not here to perpetuate something that isn't true or is misleading.

 

I hope the standard for correcting an error is nothing other than - let's do the best we can to get it right -  and not some "ruling on the field" standard.  If this is about not upsetting the FAA or not rocking the boat or not fracturing the relationship between LWX and the DC observers, then I think it is kind of a bummer. There are people in this forum who take measuring very seriously.  We have trained spotters who post here and Cocorahs folks and ACON folks, and skilled hobbyists.  Accuracy is a source of pride here.  Mapgirl has made professional maps the last 2 winters based on our reporting.  We are creating a body of work.  So, I'd hope folks who are the stewards of official historic records work their hardest to maintain the integrity of that record, if we are putting that much effort into an unofficial reference.  

 

If the FAA erred, so be it. Hopefully LWX will fix it if that is the case.  If it ends up being 17.8", so be it and it doesn't change the fact that LWX/FAA are still good people who do good work.  Agreeing to disagree is healthy. But it would be kind of a bummer if it is because some arbitrary standard got in the way of just trying to get it right.  

 

Well said.

 

I've been following this topic thread on and off the past week, with interest and a bit of bemusement.  Granted, I'm not nearly as familiar with the intimate details of the snowfall measuring history at DCA as some of those who have posted in here.  There have always been questions about DCA's snowfall in every major event...some warranted, some not (i.e., weenies who want to see them report more, etc.).  This case here, the questions sure seem to be quite warranted from what I'm reading.  I also find it puzzling that they got a mere 0.8" in that two hour period when we were right in the heart of the heavy deformation band snows, which was falling everywhere locally.  Not to mention whatever bit fell after ~5PM.  I do find it interesting that there are 5 reports within DC itself that are >20"; I don't even that was the case during the Feb. 5-6, 2010 Snowmageddon event (there was one around 25" in the far NW part of the District as I recall).

 

I'll freely admit that the weenie side of me kind of rolls my eyes almost every time I see DCA's report from any decent or better snow event.  I tend to pass that off as either that location is just in a not so great spot, or it's not always "representative" of the District as a whole.  Obviously, areas outside DC itself will tend to get more (sometimes much more) snow in any given event.  There are also many times that DCA's number is pretty in line with other reports immediately in and around the District.

 

Perhaps in the grand scheme, it doesn't mean much to banter over an inch or perhaps more(?).  Yet the thing is, in terms of historical perspective and all that, it does make a difference in terms of standing because there are a few storms grouped close together in their amounts, especially since the reporting location was moved to the DCA site location.  Of course you have the Knickerbocker storm (28.0) and the one in 1899 (20.0) that stand head and shoulders above the rest.  But since moving to DCA, there is (in order of amount) PD-I (18.7), then Snowmageddon (17.8) tied with this latest event (17.8).  A mere tenth of an inch more and this January's blizzard stands alone in 2nd place at the DCA location.  Another inch and it tops PD-I as the most at DCA.  Another couple of inches and it pushes or breaks 20".  When it started, I thought for sure this storm would top Feb. 5-6, 2010 without question, and that DCA would make a pretty easy run at cracking 20".  Not saying that this should necessarily "influence" decisions, but pointing it out as a matter of interest and the fact that a few tenths can make a difference in the standing, so to speak.

[isohume]

The question is whether it was actually 17.8" at the afternoon total.  Apparently the observer late in the day threw out all previous readings and started from scratch.  Which means the 17.8 was not correct yet.  Supposedly.

 

I'm not saying I *know* the 17.8 is right.  I'm saying simply that the evidence for changing it isn't solid.  The whole thing is definitely a mess.  Maybe it will get changed, I don't know.  The only thing I can say with certainty is that the snow depth they've reported in the last couple days is correct.

 

Glad that's your mess. lol. Anyway, NCDC will weigh all the evidence and factors for the final total. 

[famartin]

Glad that's your mess. lol. Anyway, NCDC will weigh all the evidence and factors for the final total. 

Usually they go by what the WFO says.  So, if we leave it 17.8, it will stay.  Its kinda on our back to change it or leave it.  Though, with the national exposure, we're no longer in total control. 

[isohume]

Usually they go by what the WFO says.  So, if we leave it 17.8, it will stay.  Its kinda on our back to change it or leave it.  Though, with the national exposure, we're no longer in total control. 

 

True...but if things are still uncertain they have good QC tools and procedures they use for the final climate summary.  

[famartin]

True...but if things are still uncertain they have good QC tools and procedures they use for the final climate summary.  

For COOPs, yes.  They treat first order stations differently. 

[Deck Pic]

Yes, the evidence *HAS* to be overwhelming.  And its not, quite frankly.  I know you are invested in this storm being a higher rank than tied with Snowmageddon for some reason.  Isn't it good enough that its top 3 at your house?  Or whatever it is there?

 

As far as snowfall changes in the F6's... how do you know such changes were not due to data entry error?  Did you see a statement that said "data changed due to such and such"?  The one case I am aware of where a substantial edit was made was BWI in Snowmageddon, and in that case it was downgraded to the max depth because the observer was over-measuring.  So, I'm not sure what you are expecting with DCA.

 

Really.  Where is this rule written?  Is it applicable across the entire NWS?  How does the language read?  Is it available to the public?  

[famartin]

Really.  Where is this rule written?  Is it applicable across the entire NWS?  How does the language read?  Is it available to the public?  

You're talking about re-writing something that neither you nor I observed, but someone else did (and recorded it as such).  If we wanted to go fiddle with everything that seems a little off, it would never end. 

[Deck Pic]

You're talking about re-writing something that neither you nor I observed, but someone else did (and recorded it as such).  If we wanted to go fiddle with everything that seems a little off, it would never end. 

 

So this is not a rule?  When you used the words "Yes, the evidence *HAS* to be overwhelming.", what was your source?  Were you speaking on behalf of LWX or NWS?  What is the source for the standard?  

[famartin]

So this is not a rule?  When you used the words "Yes, the evidence *HAS* to be overwhelming.", what was your source?  Were you speaking on behalf of LWX or NWS?  What is the source for the standard?  

I'm speaking on behalf of meteorological common sense.  The same sense that says there are microclimates and there will be small differences over the area.  Outside of the issues with the evening observer throwing out the previous observations and starting from scratch, there is no compelling evidence that says DCA's total is wrong.  At least, none that I'm aware of.  Its a bit low, but not obviously wrong. 

 

Take a minute and forget that there were any totals reported from DCA before the final (because, that's what the last observer apparently did).  Then look at all the totals together.  Is it a little low?  Yes.  Is it obviously wrong?  No. 

[Deck Pic]

I'm speaking on behalf of meteorological common sense.  The same sense that says there are microclimates and there will be small differences over the area.  Outside of the issues with the evening observer throwing out the previous observations and starting from scratch, there is no compelling evidence that says DCA's total is wrong.  At least, none that I'm aware of.  Its a bit low, but not obviously wrong. 

 

Take a minute and forget that there were any totals reported from DCA before the final (because, that's what the last observer apparently did).  Then look at all the totals together.  Is it a little low?  Yes.  Is it obviously wrong?  No. 

 

 

Thanks, I assumed you invented the standard out of thin air.  

[WEATHER53]

You're invested in building a case against altering the record, and I am not entirely sure why. Is this like a football challenge where we defer to the call on the field and the evidence has to be overwhelming? Or is there some other standard that we are unaware of?

I've been following snowfall data here religiously for 12 years now, and there have been a number of changes to preliminary totals for all 3 airports, and not just based on some data entry error, and not just moderate to major events. I have a body of work here staunchly defending DCA's snow totals for most storms - - I can pull up the posts if needed - - especially the last 2 winters. I am not gunning for anyone.

IF, and someone in the know is free to correct the record if it needs to be corrected. IF my understanding is correct, they had one snowboard, and it got buried in the snow at some point and they couldn't find it. So they had to improvise. At 2:52 pm, 17" had fallen. I have video from 2:51 pm, and it is apocalyptic looking in downtown DC yet somehow only 0.8" fell the next 2 hours. At 4:52 pm when it was still snowing hard, evidenced not only by the 4:52 OB, but also by the fact that 0.04" liquid was captured in the following hour (we know it is probably at least 0.06"), they measured 17.8", and quit measuring the storm. So, just to be clear. They measured 17.8" at 4:52 PM - almost certainly a snow depth measurement - and finalized the total. And then it snowed for another 7 hours. Again. If I am not getting the facts right, someone can please feel free to correct me. I am not here to perpetuate something that isn't true or is misleading.

I hope the standard for correcting an error is nothing other than - let's do the best we can to get it right - and not some "ruling on the field" standard. If this is about not upsetting the FAA or not rocking the boat or not fracturing the relationship between LWX and the DC observers, then I think it is kind of a bummer. There are people in this forum who take measuring very seriously. We have trained spotters who post here and Cocorahs folks and ACON folks, and skilled hobbyists. Accuracy is a source of pride here. Mapgirl has made professional maps the last 2 winters based on our reporting. We are creating a body of work. So, I'd hope folks who are the stewards of official historic records work their hardest to maintain the integrity of that record, if we are putting that much effort into an unofficial reference.

If the FAA erred, so be it. Hopefully LWX will fix it if that is the case. If it ends up being 17.8", so be it and it doesn't change the fact that LWX/FAA are still good people who do good work. Agreeing to disagree is healthy. But it would be kind of a bummer if it is because some arbitrary standard got in the way of just trying to get it right.

This is so nicely stated. Mr Zwyths and Many others belittled me when I started talking about this over 10 years ago. I do not resent that as actions have been taken there thst have vindicated me. It's nice to be right

The "losing the snowboard" is like the fireman losing the fire truck. Come on.

Jason and Ms Fritz did a good article but the real deal there may be known only by me and if you think that is baloney then ask yourself how wrong have I been so far?

[Deck Pic]

DCA 12:52...2.6" on 0.27" liquid (probably low)

 

I think we are reaching the point where LWX has a responsibility to correct whatever is going on there.  

[Kat]

DCA 12:52...2.6" on 0.27" liquid (probably low)

I think we are reaching the point where LWX has a responsibility to correct whatever is going on there.

Love the official site to be at the zoo. At least we could count on them accurately recording information. That said, Central Park has recording issues as well. They seem to break snowfall records with every snow shower so I don't think recording snow is an exact science.

[MacintoshPro]

DCA is at 26 degrees. Unless they really got stuck between bands, there is no way they had less than 3". This is not your typical meltfest. Something weird is going on here.

[Kat]

DCA is at 26 degrees. Unless they really got stuck between bands, there is no way they had less than 3". This is not your typical meltfest. Something weird is going on here.

Look at the NWS snow reports. 4 inches in Arlington one mile from the airport, nothing in Alexandria under 3.5 inches. It's amazing.

[Deck Pic]

I am not seeming so crazy about their issues recently Huh?

 

I think your problem was that you conflated too many issues and had no interest in a dialogue about them. Many of your assertions, especially about UHI were/are wrong. And you were derisive and dismissive when evidence was presented to counter your assertions. Sometimes the evidence was irrefutably factual.  Like you would say Andrews is 14, and Andrews would be 19.  You had no interest in rational discussion.  You think you know more than scientists.  And you were incredibly disrespectful and downright childish when someone tried to engage you on any of these things.  I don't see any reason to re-litigate these things.  You're a disingenuous person when it comes to certain issues.  

 

You've wasted way too much of my time over the years.  And it's too bad, because you made some very good points mixed in with all the nonsense and the blatant disrespect toward me.  No mea culpa for people who have behaved like you have.  You haven't earned it.

[weatherbook]

I was at the Tidal Basin at noon today and there was almost 4" of snow on the ground.  There was no wind, no melting, and the snow was quite easy to measure.

[haudidoody]

3.7" north Old Town just before the rain started...