DCA Snowfall Total Controversy

[winterymix]

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 rthat 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.

All true. One issue is that DCA needs a full suite of measurements for pilots.

The other issue is that DC residents have a right to have their storms recorded properly.

Measure the snow at the Arboretum or the Zoo or Rock Creek or the WH.

Don't make snow records just across the river from Foggy Bottom.

Gov't: spend the money, be scientific.

[MacintoshPro]

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

 

 

I understand DCA's snow total at Snowmageddon more than this, as that was an event where DCA was destined to do bad... with temperatures starting in the high 30s there. But I agree that their precipitation total was complete trash. This one, I don't know where they came up with 17.8. Temps were cold, it snowed a lot, and DCA actually looked like it was in a good spot for the whiteout bands that came through from 2-7. And its also ridiculous they didn't get any snow after 7. They should have at least broken the Snowmageddon record with the additional band or two that came through last night.

[winterymix]

Government needs to spend the money.

[codfishsnowman]

so then IAD probably only had two feet or a touch more during the early feb storm of 10??

 

this is a fascinating subject to me

 

its totals that are eight to twelve inches different depth compared to snowfall that drive me nuts during big events

[MN Transplant]

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

Garbage from this storm too.

[gymengineer]

so then IAD probably only had two feet or a touch more during the early feb storm of 10??

this is a fascinating subject to me

its totals that are eight to twelve inches different depth compared to snowfall that drive me nuts during big events

No, IAD's snow depth in 2/5-6/10 was likely wrong. All spotter/Cocorah reports were significantly more than 2 ft nearby. To give another example, IAD only reported 8" in 2/06, which made no sense compared to all nearby reports.

[wxdude64]

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.

I'll agree with this. I'm not from the area, but have been in DC a few times and at National itself a couple. With all the reports in area and whatnot, a good 1.8-2.2 likely needs added. So just make it 19.8 IMO. Amazing that they did so well and matched good until after the 7am measurement, then downhill it slid.

[Deck Pic]

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

 

I think it is actually Old Town.  As you know this was a really drifty storm and hard to measure.  17" is possible.  It is also probably the result of serious compaction and drifting. I think it was really hard to get a level measurement in a place that wasn't drifted into or out of.  

 

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?

 

I thought maybe a few tenths after 6:52.  Then again, if they picked up 0.8" in 3 hours, some -SN after 6:52 wasn't going to cut it.

 

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.

 

17.9"?   Probably 18.5"-ish.  Maybe 19".  I think they got more than 0.8" from 4-7pm.  They recorded 0.09" Precip.  We know with their bucket issues (see 2/5/10) they probably got closer 0.15+.  I think it is reasonably to think they got 1.5" in that period which would put them at 18.5".  I really really wish I hadn't had so much trouble measuring. I'm in a really good spot to QC their total based on the last 2 winters and how we run against each other.  I may go take some  more measurements soon.  But based on my best estimates last night, I think I probably got 18.5" had I properly measured the storm according to protocols.

 

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. 

 

I think BWI also had inches shaved off of Dec 2009.  And their 29" total for this storm is curious.  I think DCA has been pretty dead on the last 2 winters.  People don't quite comprehend how bad it is down there to measure.  But when you are talking a historic event with a high public profile, I can understand the frustration with not doing your hardest to get it right, even if the ultimate result is not far off from the advertised one.

[codfishsnowman]

No, IAD's snow depth in 2/5-6/10 was likely wrong. All spotter/Cocorah reports were significantly more than 2 ft nearby. To give another example, IAD only reported 8" in 2/06, which made no sense compared to all nearby reports.

i was surprised dca amount yesterday, i had the tv on all day and they looked like they got ripped in the afternoon...but for that zone just nw and w...good gravy...talk about buried

[Ian]

Garbage from this storm too.

Haven't even looked. How much?

[wxdude64]

I think it is actually Old Town.  As you know this was a really drifty storm and hard to measure.  17" is possible.  It is also probably the result of serious compaction and drifting. I think it was really hard to get a level measurement in a place that wasn't drifted into or out of.  

 

 

I thought maybe a few tenths after 6:52.  Then again, if they picked up 0.8" in 3 hours, some -SN after 6:52 wasn't going to cut it.

 

 

17.9"?   Probably 18.5"-ish.  Maybe 19".  I think they got more than 0.8" from 4-7pm.  They recorded 0.09" Precip.  We know with their bucket issues (see 2/5/10) they probably got closer 0.15+.  I think it is reasonably to think they got 1.5" in that period which would put them at 18.5".  I really really wish I hadn't had so much trouble measuring. I'm in a really good spot to QC their total based on the last 2 winters and how we run against each other.  I may go take some  more measurements soon.  But based on my best estimates last night, I think I probably got 18.5" had I properly measured the storm according to protocols.

 

 

I think BWI also had inches shaved off of Dec 2009.  And their 29" total for this storm is curious.  I think DCA has been pretty dead on the last 2 winters.  People don't quite comprehend how bad it is down there to measure.  But when you are talking a historic event with a high public profile, I can understand the frustration with not doing your hardest to get it right, even if the ultimate result is not far off from the advertised one.

I still think the next time a 'big' storm is being called for someone needs to set up a snowboard and CoCoRaHS rain gauge in the near vicinity of DCA (maybe the lower south end runway off Thomas Ave in one of the parking lots areas?) and do a comparison? Maybe a few storms in a row to get a 'feel' for exactly how off or on they truly are.

[MacintoshPro]

I think it is actually Old Town.  As you know this was a really drifty storm and hard to measure.  17" is possible.  It is also probably the result of serious compaction and drifting. I think it was really hard to get a level measurement in a place that wasn't drifted into or out of.  

 

 

I thought maybe a few tenths after 6:52.  Then again, if they picked up 0.8" in 3 hours, some -SN after 6:52 wasn't going to cut it.

 

 

17.9"?   Probably 18.5"-ish.  Maybe 19".  I think they got more than 0.8" from 4-7pm.  They recorded 0.09" Precip.  We know with their bucket issues (see 2/5/10) they probably got closer 0.15+.  I think it is reasonably to think they got 1.5" in that period which would put them at 18.5".  I really really wish I hadn't had so much trouble measuring. I'm in a really good spot to QC their total based on the last 2 winters and how we run against each other.  I may go take some  more measurements soon.  But based on my best estimates last night, I think I probably got 18.5" had I properly measured the storm according to protocols.

 

 

I think BWI also had inches shaved off of Dec 2009.  And their 29" total for this storm is curious.  I think DCA has been pretty dead on the last 2 winters.  People don't quite comprehend how bad it is down there to measure.  But when you are talking a historic event with a high public profile, I can understand the frustration with not doing your hardest to get it right, even if the ultimate result is not far off from the advertised one.

 

 

DCA has been good past two years save a few. February 2014 Coastal they got something like 6.5", lowest total for 40 miles around them. I got twice that here. You even got an inch or two more than that based on your snowfall total chart for the past couple years. This one surprises people because the usual mixing/ratios/sfc temp issues that DCA is prone to didn't apply as much. It makes you wonder what would need to happen for DCA to record 20"+

[Ian]

I understand DCA's snow total at Snowmageddon more than this, as that was an event where DCA was destined to do bad... with temperatures starting in the high 30s there. But I agree that their precipitation total was complete t

rash. This one, I don't know where they came up with 17.8. Temps were cold, it snowed a lot, and DCA actually looked like it was in a good spot for the whiteout bands that came through from 2-7. And its also ridiculous they didn't get any snow after 7. They should have at least broken the Snowmageddon record with the additional band or two that came through last night.

Yeah my guess for the airport didn't factor in the usual issues because they were not present. I've spoken to Jason a little about this yesterday. I'll just say the observers deserved the call out based on what they told him and Angela.

[Kat]

All true. One issue is that DCA needs a full suite of measurements for pilots.

The other issue is that DC residents have a right to have their storms recorded properly.

Measure the snow at the Arboretum or the Zoo or Rock Creek or the WH.

Don't make snow records just across the river from Foggy Bottom.

Gov't: spend the money, be scientific.

I understand DCA measurements need to continue. Of course they should. I'm just arguing as you are that we invest in a station in the district for the official reporting station. To me the zoo is perfect and there are people that care about scientific measurements. If the NWS is going to trust its measurements by others, that would be a great place.

[gymengineer]

Yeah my guess for the airport didn't factor in the usual issues because they were not present. I've spoken to Jason a little about this yesterday. I'll just say the observers deserved the call out based on what they told him and Angela.

That part is a mystery to me: so CWG has been able to pre-empt the NWS in releasing DCA totals for several bigger events recently. Then the NWS puts out a tweet saying there aren't any official numbers until the 6-hr interval.

 

Without quoting Jason, can you give us an idea of the content/tone of that call? 

[Deck Pic]

This is a pretty compelling time lapse from someone who lives just off rt 1 in Old Town. I think DCA's 0.8 during a productive 3 hour period is suspect.

 

[RodneyS]

I understand DCA's snow total at Snowmageddon more than this, as that was an event where DCA was destined to do bad... with temperatures starting in the high 30s there. But I agree that their precipitation total was complete trash.

Initially, the February 5-6, 2010 IAD precipitation totals were given for each day as only 0.99 and 0.61 inches (total 1.60), and the DCA precipitation totals were given as only 0.68 and 0.31 inches (total 0.99).  However, many days later, those numbers were drastically revised at IAD to 1.47 and 1.98 inches (total 3.45) and revised to a lesser extent at DCA to 0.77 and 0.73 inches (total 1.50).  The only revision to the snow numbers at either airport was that the first day's snow total at IAD was revised from 11.5 inches to 14.9 inches. That boosted the IAD snow total for the storm from 29.0 inches to 32.4 inches. 

[Deck Pic]

That part is a mystery to me: so CWG has been able to pre-empt the NWS in releasing DCA totals for several bigger events recently. Then the NWS puts out a tweet saying there aren't any official numbers until the 6-hr interval.

 

Without quoting Jason, can you give us an idea of the content/tone of that call? 

 

Angela Fritz ‏@angelafritz  Jan 23

People in Arlington measuring, 16, 17, 18 inches, and DCA is at 14.8 and "highly estimated." Losing my mind.

5 retweets3 likes

 

 

[wxnut]

I'll never understand why or how the NWS let the FAA take over ASOS and Obs. Yes-man agency syndrome for sure, but when it consistently messes with climo and TAFs it needs to change.     

 

We have the same issue in Canada.. NavCanada (similar to FAA) took over weather observations from Env Canada in the early 2000s. Until then, EC observers took weather observations at airports, including snowfall. EC observers were much more vigilant with proper snowfall measurements.  Snowfall is not a priority for aviation (just visibility and ceiling are), so NC observers either don't take them or they have to be paid extra to do it. Either way, snowfall observations from our main airport sites have suffered ever since. More and more, Env Canada has to rely on volunteer observations (coop, COCORAHS, storm spotters, etc) to get any decent snowfall numbers.  

 

The problem is we have several major sites which had a long history of snowfall observations.. and now, that snowfall record is compromised or ended. That's what irks me.. the loss of continuity for proper climatic analysis of snowfall data.        

[Ian]

That part is a mystery to me: so CWG has been able to pre-empt the NWS in releasing DCA totals for several bigger events recently. Then the NWS puts out a tweet saying there aren't any official numbers until the 6-hr interval.

 

Without quoting Jason, can you give us an idea of the content/tone of that call? 

Well they have the phone to the observer so I think they were calling in every hour to keep track of where it fell in the records. I'm honestly not sure how that part in itself works since official obs shouldn't be every hour. Basically, how I took it at least, at some point they just decided they weren't going to find a higher total than they'd already measured so they didn't even add numbers. And they weren't following proper procedure prior as far as where to measure, and seemingly when.

[wxnut]

I see the White House COCORAHS site had a 21.9" storm total..  perhaps that is more representative of DC as a whole?

[Deck Pic]

Well they have the phone to the observer so I think they were calling in every hour to keep track of where it fell in the records. I'm honestly not sure how that part in itself works since official obs shouldn't be every hour. Basically, how I took it at least, at some point they just decided they weren't going to find a higher total than they'd already measured so they didn't even add numbers. And they weren't following proper procedure prior as far as where to measure, and seemingly when.

 

This makes sense.  This is a storm where you shove your ruler into the ground after a period of heavy snow and because of compaction and drifting, you may get the same total as before or even less depending where you're measuring.

[Deck Pic]

I see the White House COCORAHS site had a 21.9" storm total..  perhaps that is more representative of DC as a whole?

 

hmmmm...I wonder exactly where he measures.  I am 5 block northeast of the white house at a higher elevation, and i don't think I got near 21.9"

 

wow...If this guy is close to me and measured properly, then I got more snow than I thought

 

http://www.cocorahs.org/ViewData/StateDailyPrecipReports.aspx?state=DC

 

hmmmm...If he does measure in Presidents Park at the spot in the map, that is 30' elevation.  I would have to do as well or better than him or at least no less than 0.5-1" worse

 

http://data.cocorahs.org/cocorahs/maps/?country=USA&state=DC&lat=38.895768&lon=-77.036975&date=1/24/2016

[Ian]

This makes sense.  This is a storm where you shove your ruler into the ground after a period of heavy snow and because of compaction and drifting, you may get the same total as before or even less depending where you're measuring.

It does depending on when. They came to that conclusion too early. They were basically making up numbers for the last few hours at least it seems.

[gymengineer]

It does depending on when. They came to that conclusion too early. They were basically making up numbers for the last few hours at least it seems.

Thanks for your explanation. Yeah, that is just not even close to following procedure. 18" snow depth then? 

[Deck Pic]

It does depending on when. They came to that conclusion too early. They were basically making up numbers for the last few hours at least it seems.

 

probably based on faulty rain gauge numbers...blehh...they suck.  It will probably be certified too

[haudidoody]

Is there a reason the City of Alexandria number referenced to National Harbor was pulled from the latest information statement? I had seen it change last night so assume there was a mistake.

 

0510 PM SNOW 1 WNW NATIONAL HARBOR 38.80N 77.05W
01/23/2016 M20.0 INCH CITY OF ALEXANDRIA VA TRAINED SPOTTER

 

0755 PM SNOW 1 WNW NATIONAL HARBOR 38.80N 77.05W
01/23/2016 M17.0 INCH CITY OF ALEXANDRIA VA TRAINED SPOTTER

[Kat]

Thanks for your explanation. Yeah, that is just not even close to following procedure. 18" snow depth then?

In the superstorm of 93, they reported 6 inches. Areas within 3 miles were at 10-15 despite sleet issues. The next day they reported snow depth higher than the amount of snow that fell-I believe more than just rounding up but that's possibly how i choose to remember it because I'm still bitter about their reporting of that storm.

[Deck Pic]

hmmmm...I wonder exactly where he measures.  I am 5 block northeast of the white house at a higher elevation, and i don't think I got near 21.9"

 

wow...If this guy is close to me and measured properly, then I got more snow than I thought

 

http://www.cocorahs.org/ViewData/StateDailyPrecipReports.aspx?state=DC

 

hmmmm...If he does measure in Presidents Park at the spot in the map, that is 30' elevation.  I would have to do as well or better than him or at least no less than 0.5-1" worse

 

http://data.cocorahs.org/cocorahs/maps/?country=USA&state=DC&lat=38.895768&lon=-77.036975&date=1/24/2016

 

And a trained spotter got 22.3" 1.5 miles due east of me at a lower elevation...hmmm...

 

http://www.weather.gov/lwx/pnsmap?type=snow

[Ian]

Pretty sure it's an official WH location. South Lawn somewhere.