DCA Snowfall Total Controversy

[GEOS5ftw]

Kind of tangential to the topic but how long has the snowboard/6 hour technique been in practice? I'm wondering if Knickerbocker/1899 amounts were measured using this method or just final snow depth - if the latter, that makes them even more impressive, and also harder to compare to more recent events.

[Deck Pic]

In a case like this I think you have to make a ton of measurements in places that do not seem disturbed. Obviously they aren't doing that at DCA.

 

I think that is part of it.  Some people don't care about getting it right.  All this controversy aside, I can't imagine I got more than 18.5 - 19". I think DCA's total might just pass a Quality check process and be certified.  I don't think people quite realize how bad it is there to measure snow. They think DCA got like 21"..No chance..

[Deck Pic]

Damn...I just took a 15 minute hot shower and am sitting on my couch in shorts and a t-shirt and this thread is now making me wanna go measure again since I gave up after 3pm or so.  I guess I'm heading out  

[Deck Pic]

Damn...I just took a 15 minute hot shower and am sitting on my couch in shorts and a t-shirt and this thread is now making me wanna go measure again since I gave up after 3pm or so.  I guess I'm heading out  

 

Well that sucked.  I can't feel my legs since I went out in shorts and was knee deep in snow.  It's really impossible to tell.  When accounting for compaction I probably got like 18.5".  I had some 20-21" measurements but they seemed drifty to me, the same way the 16.5" ones seem light.  

[Deck Pic]

When you measure, how far do you travel? I actually mapped out a measuring plan before the event, but I wasn't sure how far to go. I did a couple of blocks around my area and went about a half mile down the neighborhood twice in an attempt to quality control if that makes sense. 

 

This event, I went within a 2-3 block radius to QC my numbers, but I threw in the towel at some point because it was too drifty everywhere.  

[haudidoody]

19 inches on the ground now, more or less, so if that is at all representative, way under Feb 2010.

[uncle W]

Kind of tangential to the topic but how long has the snowboard/6 hour technique been in practice? I'm wondering if Knickerbocker/1899 amounts were measured using this method or just final snow depth - if the latter, that makes them even more impressive, and also harder to compare to more recent events.

NYC storms look like they were measured at the end of the storm from the early days...example on January 12-13th 1964 NYC recorded 12.5" of snow for a 24 hour storm...At the end of the storm there was a 13" snow depth recorded...No snow was on the ground before the storm...this one example of many snowstorms from the 1970's and before...I'm not sure this was done with every storm...Just looks suspicious to me...

[WxMan1]

#MeasurementGate

[Ian]

I think that is part of it.  Some people don't care about getting it right.  All this controversy aside, I can't imagine I got more than 18.5 - 19". I think DCA's total might just pass a Quality check process and be certified.  I don't think people quite realize how bad it is there to measure snow. They think DCA got like 21"..No chance..

National Harbor had 17". One problem is a lot of people lie so it's hard to weed out the bad reports.

[Ian]

Sometimes I worry my numbers are too high because of Matt. In this storm I actually ended up measuring on pavement a lot. I have a few fairly secluded spots for that. It did seem it was about 1" lower than others in general with that method, but as it was ongoing I didn't really care if I was perfectly accurate. I like big dumpsters and tables when I can find them -- obviously these are probably a little snowier than say a random 2x4 sitting in someone's yard. It certainly was tough by the end of this one.

 

I'm going to go out again shortly but I doubt my total will change at this point.

[Amped]

Lets complain about any 2 measurements within a mile that are 8" different, there were plenty around  where I live. II measured between 26- 32, but someone down the block from me had 22" and another 1 mile to my north had 30". The chasers at the Days Inn 2 miles away said 40". You have to average spotters to get a number that makes sense.

[NJDC Wx]

Regardless of the procedural errors and location problems, I'm not sure that DCA's final number is that far off. I wandered around Fort Reno around 5:00pm taking measurements and was getting around 18-19. It seemed a little low based on other reports here. At the time, we still had a few hours to go, so I imagine another 2" or so was added on top of it. Based on what I saw up in the highest point in DC, there's no chance DCA hit 20". My measurement was difficult with drifts and compaction, but still.

 

In my neighborhood, I think this event was very comparable to Feb 5-6, 2010 when it comes to impact and totals. DCA's number for both events would reflect that as well.

[bigredo]

Is the issue at DCA more a procedural issue of inaccurate measurement or is it the location? Would be great if someone had measured today at the old 24th & M spot and compared it to the DCA total and then you could use an adjustment scale for some of the older storms that were measured there.

[gymengineer]

Aside from the total reported at 6:52 pm, did they just stop measuring for the next period? How was there not even a tenth recorded from the snow the next few hours?

[DCWeatherGuy]

Aside from the total reported at 6:52 pm, did they just stop measuring for the next period? How was there not even a tenth recorded from the snow the next few hours?

 

Seems like they just panicked and quit when the CWG called them out.  Or maybe they're just not releasing their numbers while under "investigation" or whatever.  Either way, a fitting end to an awful effort. 

[MN Transplant]

For those really "angry" about this , how much do you think fell at DCA? Remember, this is setting aside the question about whether DCA is representative of the city/area.

[MN Transplant]

Holy lord, the comment section of the Post article.

[stormtracker]

For those really "angry" about this , how much do you think fell at DCA? Remember, this is setting aside the question about whether DCA is representative of the city/area.

That's the real issue.  Its a sea level location near a river.  But, FWIW, They probably actually got around 19..maybe 20.  There was clearly something amiss between 4 and 7pm.

 

One good thing to come from this is that I'm going to get a snowboard and start measuring myself.   Now I'm obsessed with the issue.

[DCWeatherGuy]

For those really "angry" about this , how much do you think fell at DCA? Remember, this is setting aside the question about whether DCA is representative of the city/area.

 

I really don't think that is the pertinent question.  This is the pertinent question:

 

 

....

 

Bottom line:  At 7am, DCA reported 14".  Featuring pretty ideal conditions for snow accumulation, it snowed for 13 15 hours thereafter, including multiple heavy bands that ranked the areas immediately north, south, east, and west of DCA with heavy snow, and yet DCA got 3.8 inches out of it.  Does anyone believe this is plausible? 

 

You are a trained met. If you had a chance to look at the radar and the soundings from the area yesterday, I am sure people would like to hear your view on this.  Again, we're not debating a full event total here.  We're debating a total from 7 am onward on Saturday for a location that had a regionally-typical total in the previous 18 hours of the storm.

[gymengineer]

For those really "angry" about this , how much do you think fell at DCA? Remember, this is setting aside the question about whether DCA is representative of the city/area.

I'm personally not angry- just amused by the sketchiness of big snows winding down and DCA. Remember in 12/09? Matt pointed out the confusing end of storm period where DCA ran up to 16", had precip after, but no more snow?

The 2" + 1" on the METAR's yesterday afternoon made sense, bringing the total to 18-ish depending on rounding. It was 5 pm through 11 pm period afterwards that didn't make as much sense.

I think their total was probably 1" more, around 19".

[gymengineer]

And it's not just DCA. All three airports have had totals called into question-- even rejected. Remember, BWI's total for 2/5-6/10 was rejected by LWX, with them "making up" a final storm total based on snow depth. 

 

IAD in 12/09 had 18.0" total alongside an 18" snow depth the morning after it ended--- so what? 0 to 0.5" compaction for the whole storm? Then LWX took over from IAD and made their storm total measured at Sterling the total for 2/5-6/10. That yielded the interesting 32.4" snow total (measured at Sterling) with only a 21" snow depth (measured at IAD). 

 

So, it's not like it's just a bunch of weather weenies who actually care about measurements. I wonder if after all that commotion in 09/10, with talk of possibly adjusting BWI totals in past storms, LWX has just kind of given up trying to fix the situation. 

[RodneyS]

 

That all said, they have completely blown a few storms IMO including Feb 2010 where I diverged terribly. 

As i noted on the Washington Post Capital Weather Gang thread on this subject:

 

During the February 5-6, 2010 Snowmageddon storm, there was difficulty measuring the precipitation totals at both DCA and IAD due to high winds, as snow blew around the precipitation gages instead of into them. The reported totals at both airports were subsequently examined and adjusted sharply upwards, to 1.50 inches at DCA and 3.45 inches at IAD. Based on the reported snow totals of 17.8 inches at DCA and 32.4 inches at IAD, the snow/precipitation ratio at DCA was higher than at IAD. That would tend to indicate that the reported snow total at DCA was not too low, but rather was simply a function of DCA not being in the bulls-eye for that storm, whereas IAD was. This time, both the precipitation and snow totals at DCA appear low, but let's wait to see what an examination of both totals reveals.

[Kat]

The total is not that far off, not the egregious offense that occurred in 2010. That said, the problem is the total is not how much snow fell. You'll note the snow depth is higher than the NYC locations at DCA but snowfall is much less. If they don't clean the board and actually measure snowfall, it's a comparison of apples and oranges. DCA isn't measuring what other locations are measuring. They're measuring some strange hybrid mix of snow depth and snowfall. That's one issue. The other issue is that DCA is not the most representative location for the city, and def not the area as a whole. Need a spot back in DC. I'm not suggesting we no longer use DCA measurements, just that we add an additional official location in DC itself. The two are not mutually exclusive-we can have both and just have more accurate data for the district.

[Random Chaos]

I wonder where at DCA the readings take place, and whether it is truly a location without drifting. My anemometer had NE winds throughout the night Friday into Saturday. The bands that came through Saturday afternoon and evening though shifted the wind N. DCA is located along a north-south location on the Potomac river that is likely more affected by N winds than by NE winds. Could be something to look into as to why the readings seemed good for Friday night into Saturday, but really wacky for Saturday afternoon and evening.

[MacintoshPro]

The total is not that far off, not the egregious offense that occurred in 2010. That said, the problem is the total is not how much snow fell. You'll note the snow depth is higher than the NYC locations at DCA but snowfall is much less. If they don't clean the board and actually measure snowfall, it's a comparison of apples and oranges. DCA isn't measuring what other locations are measuring. They're measuring some strange hybrid mix of snow depth and snowfall. That's one issue. The other issue is that DCA is not the most representative location for the city, and def not the area as a whole. Need a spot back in DC. I'm not suggesting we no longer use DCA measurements, just that we add an additional official location in DC itself. The two are not mutually exclusive-we can have both and just have more accurate data for the district.

 

 

Agreed. We really need a station in DC. I'd like the White House bc they already have a thermometer and rain gauge but somewhere like the zoo works as well.

[NinjaWarrior2]

I don't think DCA's snowfall measurement was that outrageous, DCA is a location where it is almost impossible for them to get more snow than someone 1 mile west. During Nor'easters, they get gusts off the river which effects their snowfall totals. But on the other hand, I do agree with the opinions on moving the official measuring station to somewhere in DC (like maybe the Verizon Center, DuPont Circle, etc).

[needbiggerboat]

Why measure District of Columbia snowfall in Arlington, Virginia?

Measuring technique can be tweaked but it's still going to be another set of VA obs until they move the location to DC.

[MN Transplant]

I really don't think that is the pertinent question. This is the pertinent question:

You are a trained met. If you had a chance to look at the radar and the soundings from the area yesterday, I am sure people would like to hear your view on this. Again, we're not debating a full event total here. We're debating a total from 7 am onward on Saturday for a location that had a regionally-typical total in the previous 18 hours of the storm.

I sent in my CoCoRahs report as 7.2" from 7am yesterday. Based on radar, I was in a better position than DCA. I could see maybe ~ 5" there, which would mean than they were 1-2" low during blizzard conditions. I am not sure how they would have got a good reading at the airport, but I do know that a snow board reading would fail.

[Inverted_Trough]

BOS, JFK and PHL are even windier airports than DCA.  How do they measure it?

There are several other airports with a similar profile to DCA, i.e., at sea level next to a body of water.  PHL is next to the Delaware River.  What makes DCA unique from PHL?

 

I have a feeling their final numbers will be certified, unfortunately.  Maybe we should start a Change.org petition to have a DC station 

[Ian]

As i noted on the Washington Post Capital Weather Gang thread on this subject:

During the February 5-6, 2010 Snowmageddon storm, there was difficulty measuring the precipitation totals at both DCA and IAD due to high winds, as snow blew around the precipitation gages instead of into them. The reported totals at both airports were subsequently examined and adjusted sharply upwards, to 1.50 inches at DCA and 3.45 inches at IAD. Based on the reported snow totals of 17.8 inches at DCA and 32.4 inches at IAD, the snow/precipitation ratio at DCA was higher than at IAD. That would tend to indicate that the reported snow total at DCA was not too low, but rather was simply a function of DCA not being in the bulls-eye for that storm, whereas IAD was. This time, both the precipitation and snow totals at DCA appear low, but let's wait to see what an examination of both totals reveals.

The DCA precip total from Snowmageddon is likely garbage as well. Go look at cocorahs reports that day.