Mid-Atlantic snow totals for winter 2017/18

[North Balti Zen]

12/9/17 - 2.5”

12/13/17 - .8"  (really pleasant surprise, streets covered right away)

12/15/17 - .9” - another pleasant light event 

12/30/17 - .2"

1/4/18 - 1"

1/8/18 - glaze of ice on sidewalks/side streets

1/17/18 - 1"

1/30/18 - T

2/4/18 - T (w/ .1 of ice accretion)

2/17/18 - 2"

3/2/18 - T (flurries in wind event)

3/6-7/18 - 1.5" (slushy, no sidewalk/street coverage)

3/12/18 - T

3/20-21 - .5 ice from first wave and 5" from second wave

Running snow total - 14.9”

PS - I no longer loathe the winter, as I finally got a verified warning level snow event.

[KingJWx]

See my signature, total is 11.1"

[EastCoast NPZ]

12 hours ago, Fozz said:

Damn... I'm sorry about the most recent one. That's really an epic screwjob, and it's not like this past winter hasn't had countless others. 

Indeed, I much preferred last winter.  Same total snow, but didn't have to suffer through 20 D7-modeled events that disappeared by D4, the 3 weeks of cold in January that produced nothing but a high gas bill, and then the epic March block that produced 3 whiffs, 2 weeks of non-stop wind, and the final departing kick to my groin to end the season.  I hope next winter is wall-to-wall torch; I'm done with it until the day I finally leave the screw-zone that is the northern Shenandoah Valley.

[KingJWx]

Also, here's Ryan Maue's maps for the 3/20-21 event and for the season:

[North Balti Zen]

His 20 in Baltimore City for a seasonal total is off. For sure.

[EastCoast NPZ]

Ryan Maue needs some help with his maps.  No where close to 6" of snow in this part of Fred Co., although is to-date seasonal total map looks right.

[Fozz]

13 minutes ago, KingJWx said:

Also, here's Ryan Maue's maps for the 3/20-21 event and for the season:

 

First map looks about right for our area, but Philly did not get 19" from that storm. Also York county received about 10-15", not 20+.

Where does he get those numbers?

[mappy]

I think you guys need to understand how hard it is to make maps like that, if you only have so much data to work with. While I agree York County looks incredibly overdone for the storm... it could be bad data that he is using causing it to so much higher. Which is why I have said time and time again how important it is to take good measurements and give the best up to date information you can give. It will really screw things up otherwise. 

[Fozz]

10 minutes ago, mappy said:

I think you guys need to understand how hard it is to make maps like that, if you only have so much data to work with. While I agree York County looks incredibly overdone for the storm... it could be bad data that he is using causing it to so much higher. Which is why I have said time and time again how important it is to take good measurements and give the best up to date information you can give. It will really screw things up otherwise. 

I understand. I'm just genuinely curious about where he got those crazy PA numbers from, or whether he considered Philly's reported total of 7.6" before putting the city in the 18" shade. Hopefully it will be quality controlled and revised.

[Sparky]

12/9/17 - 6.5"

12/13 - .5"

12/15 - .5"  

12/30 - .75"

1/4/18 - 1"

1/13 - .25" 

1/17 - .75"

1/30 - 1"

2/4 - .5"

2/17 - 2.25"

3/2 - .75"

3/7 - 1.25"

3/12 - .5"

3/20-21 - 13"

Total - 29.5" (annual avg. is 35")

[Fozz]

Here's an updated map of the latest storm based on spotter reports and other sources. Looks much more accurate to me.

 

[mappy]

14 minutes ago, Fozz said:

I understand. I'm just genuinely curious about where he got those crazy PA numbers from, or whether he considered Philly's reported total of 7.6" before putting the city in the 18" shade. Hopefully it will be quality controlled and revised.

from here

https://www.nohrsc.noaa.gov

[mappy]

There are some high totals in York County. a 25 outside Lancaster, 22 near Hersey, 26 near Harrisburg, over the last 48 hours. 

That's why his map is so high. 

[Sparky]

4 minutes ago, mappy said:

There are some high totals in York County. a 25 outside Lancaster, 22 near Hersey, 26 near Harrisburg, over the last 48 hours. 

That's why his map is so high. 

That can't be right.

[mappy]

3 minutes ago, Sparky said:

That can't be right.

It's not. Coworker who lives in York got 15"

[Fozz]

8 minutes ago, mappy said:

from here

https://www.nohrsc.noaa.gov

Thanks. 

[mappy]

7 minutes ago, Fozz said:

Thanks. 

The interactive map shows it well, under Latest Observations, 48 hour total snowfall. Maue is pulling the wrong dataset to create his maps.

https://www.nohrsc.noaa.gov/snowfall_v2/

He needs to be using the Interpolated SF total that creates this instead. Storm total and seasonal total. 

[WxUSAF]

19 minutes ago, mappy said:

It's not. Coworker who lives in York got 15"

JB2 says he got 20” I think?

[Fozz]

4 minutes ago, WxUSAF said:

JB2 says he got 20” I think?

That sounds high. But he also did added measurements. His highest snow depth was no more than 16".

[mappy]

2 minutes ago, WxUSAF said:

JB2 says he got 20” I think?

Yeah, I heard that. Not sure where he lives in/around York.

York County...
   Dover                 15.0   930 PM  3/21  Social Media
   Seven Valleys         15.0   930 PM  3/21  Social Media
   Shrewsbury            15.0   650 PM  3/21  Trained Spotter
   2 S York              14.1   751 PM  3/21  Trained Spotter
   Hanover               14.0   704 PM  3/21  Social Media
   York                  12.7   310 PM  3/21  Trained Spotter
   Stewartstown          12.0   111 PM  3/21  Social Media
   Mount Wolf            11.5   840 PM  3/21  Social Media
   Dillsburg             11.0   821 PM  3/21  Social Media
   3 WSW Brogue           9.0   318 PM  3/21  Trained Spotter

[mappy]

5 minutes ago, Fozz said:

That sounds high. But he also did added measurements. His highest snow depth was no more than 16".

added measurements? 

[Fozz]

Just now, mappy said:

added measurements? 

Sweeping the board every 6 hours. 

[mappy]

3 minutes ago, Fozz said:

Sweeping the board every 6 hours. 

that's what you are supposed to do. I measured hourly from the time I got home at noon on tuesday until last night (other than the six hours I slept Tuesday night). I swept it every six hours, which is also when I submitted my snowfall totals. of course there was compaction, but sweeping every six is what you are supposed to do. 

[Fozz]

33 minutes ago, mappy said:

that's what you are supposed to do. I measured hourly from the time I got home at noon on tuesday until last night (other than the six hours I slept Tuesday night). I swept it every six hours, which is also when I submitted my snowfall totals. of course there was compaction, but sweeping every six is what you are supposed to do. 

I always thought the 6 hour thing was optional. It just can't be more often than every 6 hours. Some people sweep just once per day. That's what I did in this week's storm.

[EastCoast NPZ]

1 hour ago, Fozz said:

Here's an updated map of the latest storm based on spotter reports and other sources. Looks much more accurate to me.

 

Yep, this one is money.  He even got that little carved-out area of <4 inches IMBY.

[mappy]

39 minutes ago, Fozz said:

I always thought the 6 hour thing was optional. It just can't be more often than every 6 hours. Some people sweep just once per day. That's what I did in this week's storm.

Well, like all the aiports, and other climo report stations, I sweep every six after measuring every hour (when home to do so). To each their own. 

[clskinsfan]

44 minutes ago, Fozz said:

I always thought the 6 hour thing was optional. It just can't be more often than every 6 hours. Some people sweep just once per day. That's what I did in this week's storm.

It is not optional. Here is the proper way to measure: 

https://www.weather.gov/media/ffc/snow_measurement_guidelines.pdf

Measuring Snowfall

Snowfall is measured to the nearest tenth of an inch. Measure the greatest amount of snowfall that has accumulated on your snowboard since the last observation. You can measure on a wooden deck or ground if a snowboard is not available. Snowfall should not be measured more than 4 times in 24 hours. You can measure the hourly snowfall rate, but do not clean off your board each hour. Only clean off the board when you take one of the four daily measurements. Once the snow ends, add up the measurements from each time the snowboard was cleaned to reach a storm total.

Special cases:

- Snow falls and accumulates on the snowboard, but then melts. In this case, the snowfall is the greatest depth of snow observed on the board before it begins to melt. If this occurs several times, measure the snowfall after each snow shower and add each measurement for the total snowfall.

- Snow falls and melts continuously on the board. In this case, if the snow never reaches a depth of a tenth of an inch, then a trace of snowfall is recorded.

- Snow has blown or drifted onto the snowboard. In this case, take several measurements from around the yard where the snow has not drifted, being careful only to measure new snow. Take an average of the various measurements to arrive at a total.

- Sleet counts towards total snowfall, freezing rain accumulation does not.

[Fozz]

17 minutes ago, clskinsfan said:

It is not optional. Here is the proper way to measure: 

https://www.weather.gov/media/ffc/snow_measurement_guidelines.pdf

Measuring Snowfall

Snowfall is measured to the nearest tenth of an inch. Measure the greatest amount of snowfall that has accumulated on your snowboard since the last observation. You can measure on a wooden deck or ground if a snowboard is not available. Snowfall should not be measured more than 4 times in 24 hours. You can measure the hourly snowfall rate, but do not clean off your board each hour. Only clean off the board when you take one of the four daily measurements. Once the snow ends, add up the measurements from each time the snowboard was cleaned to reach a storm total.

Special cases:

- Snow falls and accumulates on the snowboard, but then melts. In this case, the snowfall is the greatest depth of snow observed on the board before it begins to melt. If this occurs several times, measure the snowfall after each snow shower and add each measurement for the total snowfall.

- Snow falls and melts continuously on the board. In this case, if the snow never reaches a depth of a tenth of an inch, then a trace of snowfall is recorded.

- Snow has blown or drifted onto the snowboard. In this case, take several measurements from around the yard where the snow has not drifted, being careful only to measure new snow. Take an average of the various measurements to arrive at a total.

- Sleet counts towards total snowfall, freezing rain accumulation does not.

It says that snow should not be cleared more than 4 times in 24 hours, or more than once every 6 hours. It doesn't say that it has to be cleared exactly that often.

LWX guidelines say pretty much the same thing.
https://www.weather.gov/media/lwx/skywarn/Winter Weather 2016.pdf

 

Also these guidelines linked directly from the LWX page say that once every 24 hours is fine, and many COOP observers do that. 
http://www.nws.noaa.gov/om/coop/reference/Snow_Measurement_Guidelines.pdf

Quote

Observers in networks such as the NWS Cooperative Observer Program network are typically required to take measurements only once per day. The SMB should be cleared at the end of the 24-hour period in preparation for measuring snowfall during the next observing period. Measure the maximum depth of snow that has accumulated on your snow measurement board (or other approved surface) since the previous snowfall observation. This measurement should reflect the greatest accumulation of new snow observed (in inches and tenths, for example, 3.9 inches) within the past 24 hours even if this total occurs at a time preceding the regularly scheduled observation time. For example: Snow begins to fall at 10:00 a.m., accumulates to 4.2 inches by 3:00 p.m. and then stops. Ideally, this is when you should measure the snow. The snow begins melting and settling such that by your observation the next morning you only have 2.6 inches of snow on your snow board. The correct number to report for your 24-hour snowfall is 4.2 inches - the accumulation prior to melting and settling.

 

[MN Transplant]

12/9/17	2.4
12/15/17	0.1
12/30/17	0.4
1/4/18	0.5
1/17/18	0.3
2/17/18	1.2
3/6/18	0.9
3/21-22/18	3.7
17-18 Seasonal	9.5

[poolz1]

On 2/19/2018 at 6:37 PM, poolz1 said:

2/17  - 2.0"

Total: 5.7"

3/20-3/21 12.5"

Season total: 18.2"

Final total...I think