So how do they measure that snow anyway?

We’re at 74.9″ of snowfall at MSP Airport so far this winter.

This is already the 10th snowiest winter on record.

1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 A 10 2100 225 top 10.jpg

We’re now ahead of the pace for the snowiest winter on record which was 98.6″ back in 1983-’84.

1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 A 10 2100 225 10 pace.jpg

Last weekend’s blockbuster storm was also the biggest February snowfall on record for the Twin Cities.

1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 A 10 2100 225 top5.jpg

How do they measure snow, anyway?

Many of you have asked how snow gets measured. Here’s the deal.

-Pick a hard flat area away from building or other obstructions that can alter snowfall patterns. A white deck surface works best, or you can create what’s called a “Boluay Board” which is basically a 16″ white plastic board. This technique was developed by Pete Boulay, a climatologist with the Minnesota State Climatology office. (We can be proud he’s one of our own!)

1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 A 10 2100 225 boulay.jpg

-Use a ruler and take several measurements, and then use an average to minimize any effects of drifting.

-Clean the board off in between measurements during a storm to get a true estimate of actual snowfall without the effect of compaction.

-To measure snow depth, pick a similar area, but don’t clean off the board to measure. This gives a true measure of snow depth, including compaction resulting for the weight of the snow.

The Twin Cities NWS uses 2 main products to report snowfall. One is the Local storm report (LSR). This is used to relay snowfall and severe weather reports as they arrive from NWS personnel and trained spotters. These reports are issued individually or in groups as they are received. Here’s an example of an LSR for snowfall.

PRELIMINARY LOCAL STORM REPORT…CORRECTED

NATIONAL WEATHER SERVICE TWIN CITIES/CHANHASSEN MN

1123 AM CST TUE FEB 22 2011

0640 AM SNOW MINNEAPOLIS 44.96N 93.27W

02/22/2011 M13.8 INCH HENNEPIN MN OFFICIAL NWS OBS

OBSERVED AT MINNEAPOLIS INTERNATIONAL AIRPORT.

Snowfall summaries are generally grouped and processed using the Public Information Statement (PIO). These summaries may contain all snowfall reports starting with the highest accumulations.

Because they contain multiple reports over irregular periods of time, PIO snowfall reports may not always be current reflection of snowfall totals at any given location if (volunteer) observers have not measured for a few hours. People should be careful to check the issuance time of PIO snowfall reports during snow events.

Here’s a PIO form our recent storm.

PUBLIC INFORMATION STATEMENT

NATIONAL WEATHER SERVICE TWIN CITIES/CHANHASSEN MN

1159 AM CST TUE FEB 22 2011

…SNOWFALL TOTALS FROM THE FEBRUARY 20TH-21ST STORM SYSTEM…

SNOW REPORTS LISTED BY AMOUNT

INCHES LOCATION ST COUNTY TIME

—— ———————– — ————– ——-

20.00 MADISON MN LAC QUI PARLE 0830 PM

19.60 BLOOMINGTON MN HENNEPIN 0825 PM

19.00 3 NW EDEN PRAIRIE MN HENNEPIN 0515 PM

18.00 CREDIT RIVER MN SCOTT 0937 PM

18.00 BURNSVILLE MN DAKOTA 0519 PM

17.50 SPRINGFIELD MN BROWN 0840 AM

16.30 1 SSW MONTEVIDEO MN CHIPPEWA 0700 AM

15.50 2 W PRIOR LAKE MN SCOTT 0900 AM

15.10 LAKEVILLE MN DAKOTA 0814 PM

15.10 RICHFIELD MN HENNEPIN 0820 PM

15.00 OSCEOLA WI POLK 0500 PM

15.00 MENOMONIE WI DUNN 0552 PM

15.00 3 SSW BURNSVILLE MN DAKOTA 0845 AM

14.20 1 N PRIOR LAKE MN SCOTT 0930 PM

14.00 INVER GROVE HEIGHTS MN DAKOTA 1002 PM

14.00 WOODBURY MN WASHINGTON 0800 AM

14.00 EDEN PRAIRIE MN HENNEPIN 0809 PM

14.00 RED WING MN GOODHUE 0730 PM

13.60 ANDOVER MN ANOKA 1024 PM

13.50 MAPLEWOOD MN RAMSEY 1210 PM

13.80 MINNEAPOLIS(MSP AIRPORT) MN HENNEPIN 1240 AM

13.70 CHANHASSEN (NWS OFFICE) MN CARVER 1240 AM

13.30 ST PAUL MN RAMSEY 0610 AM

13.00 GRANITE FALLS MN CHIPPEWA 1013 AM

12.90 3 WNW RICE MN STEARNS 0700 AM

12.70 EDINA MN HENNEPIN 0203 PM

12.70 1 NW BURNSVILLE MN DAKOTA 0700 PM

12.60 COON RAPIDS MN ANOKA 0638 PM

12.50 CARVER MN CARVER 0700 AM

12.40 HASTINGS MN DAKOTA 0907 PM

12.40 ROBERTS WI ST. CROIX 0800 AM

12.30 5 SW ST PAUL MN RAMSEY 0845 AM

12.00 1 N CAMERON WI BARRON 0500 PM

12.00 MANKATO MN BLUE EARTH 0333 PM

12.00 LAKE ELMO MN WASHINGTON 0800 AM

12.00 3 N BLOOMER WI CHIPPEWA 0730 AM

12.00 BALDWIN WI ST. CROIX 0700 AM

12.00 3 SW MINNEAPOLIS MN HENNEPIN 0900 PM

12.00 SHAKOPEE MN SCOTT 0854 PM

11.60 JORDAN MN SCOTT 0710 AM

11.50 MILROY MN REDWOOD 0700 AM

11.10 BLAINE MN ANOKA 0917 PM

11.00 DURAND WI PEPIN 1000 PM

11.00 SAUK RAPIDS MN BENTON 0800 PM

11.00 MORGAN MN REDWOOD 0702 AM

11.00 4 NNE MAPLEWOOD MN RAMSEY 0830 PM

11.00 1 ESE CHASKA MN CARVER 0800 PM

10.60 3 NNW MINNEAPOLIS MN HENNEPIN 0346 PM

10.60 MINNETONKA MN HENNEPIN 0803 AM

10.50 CLAYTON WI POLK 0616 PM

10.50 LITCHFIELD MN MEEKER 0420 PM

10.50 ELK MOUND WI DUNN 0600 AM

10.50 REDWOOD FALLS MN REDWOOD 0500 AM

10.30 7 S HILLMAN MN MORRISON 0335 PM

10.20 OAKDALE MN WASHINGTON 0747 PM

10.00 GLENWOOD MN POPE 0600 PM

10.00 ST JAMES MN WATONWAN 0700 PM

10.00 MADELIA MN WATONWAN 1245 PM

10.00 COMFREY MN BROWN 1210 PM

10.00 BROWNTON MN MCLEOD 1210 PM

10.00 NW GILMAN MN BENTON 0828 AM

10.00 ISANTI MN ISANTI 0626 AM

10.00 EAU CLAIRE WQOW WI EAU CLAIRE 0500 AM

10.00 2 N MENOMONIE WI DUNN 1100 PM

10.00 1 W CARVER MN CARVER 0900 PM

10.00 4 SSW MINNEAPOLIS MN HENNEPIN 0700 PM

10.00 ST PETER MN NICOLLET 0530 PM

9.70 WACONIA MN CARVER 0803 AM

9.70 NORTH MANKATO MN NICOLLET 0700 AM

9.50 STILLWATER MN WASHINGTON 0936 PM

9.00 ELLENDALE MN STEELE 0615 PM

9.00 CAMBRIDGE MN ISANTI 0540 PM

9.00 HUTCHINSON MN MCLEOD 1145 AM

9.00 BARRON WI BARRON 0728 AM

9.00 3 ENE MONTGOMERY MN RICE 0700 AM

9.00 LONSDALE MN RICE 0600 AM

9.00 GLENCOE MN MCLEOD 0151 AM

8.90 MONTICELLO MN WRIGHT 0915 PM

8.60 9 NNE BIRD ISLAND MN RENVILLE 0630 AM

8.50 RUSH CITY MN CHISAGO 0815 AM

8.60 ST CLOUD MN STEARNS 1240 AM

8.30 NEW ULM MN BROWN 1038 AM

8.10 BOWLUS MN MORRISON 0829 AM

8.00 VESTA MN REDWOOD 0200 PM

8.00 3 SE NEW ULM MN BROWN 0800 AM

8.00 OWATONNA MN STEELE 0800 AM

8.00 2 S ST FRANCIS MN ANOKA 0731 AM

8.00 MILACA MN MILLE LACS 0730 AM

8.00 RICE LAKE WI BARRON 0725 AM

8.00 FARIBAULT MN RICE 0700 AM

8.00 ALBANY MN STEARNS 0700 AM

8.00 CARLOS MN DOUGLAS 0552 AM

8.00 LESTER PRAIRIE MN MCLEOD 0338 PM

7.60 RICE MN BENTON 0700 AM

7.50 1 NNW COLD SPRING MN STEARNS 0600 AM

Note the wide range (from 9.5″ Stillwater to 19.6″ Bloomington) just within the metro in bold. Here’s the map.

1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 A 10 2100 225 map.jpg

Snowfall measurement is not perfect, but it is generally an accurate reflection of what’s falling if done correctly. Multiple snowfall reports from several locations are valuable and can be checked against each other to see if any totals are well out of range. Keep in mind that snowfall can vary over short distances with thundersnow and banded snowfall patterns.

Arctic rewind:

Arctic air is oozing south from Canada as we close the week. Expect temperatures to run a good 10 to 15 degrees cooler than average (Metro averages now 32/16) into Saturday.

1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 A 10 2100 225 10sfc.jpg

Arctic air oozes south.

Expect highs in the teens north and 20s south today. Arctic high pressure will strengthen through Saturday with highs in the teens south to single digits north. Lows could dip below zero south Friday & Saturday morning, and plunge into the -20s north.

With the center of high pressure ovehead Saturday, at least winds should be light.

Temperatures should recover into the 20s by Sunday.

We may see a few snow showers Friday, and there is a chance for some light snow south Saturday. A bigger snow storm may head for Chicago Sunday into Monday, but looks to pass south of our area. Right now I don’t see any blockbuster snow events on the horizon…so far.

PH

  • Eric

    I have accounts that my company plows and the reports you provide are not correct. Sorry to be so brass but the January 9-11, 2011 snow event is just one of a few that are incorrect. The report of 0.2″ is off. Other wise there would have been no need to provide service to the stillwater MN sites. That event was atleast 2.0″ The November 13th 2010 snow event is incorrect also. Stillwater received more than 3″. My contracts have clauses in them that I am not able to use because your reports for stillwater MN are so low. We do have a vast area that we provide sevice to and there has not been a drastic difference. Stillwater Oakdale,Highland park, Woodbury, St.Paul. Little Canada,Maplewood Shoreview, Eagan, Coonrapids, Blaine,Andover, Hamlake, Centerville. I am sure its not a simple or easy job to measure snow event totals. Just thought I would pass it along that stillwater had more than 46.0″ish season snow totals as of 2/15/2011. I feel anyway by plowing and yes even some shoveling. Even taking out the driffting. I have been doing this since 1998 not a terribly long time but awhile, so you dont think its some newbe sending you this. Thanks for your time please do not take this in a negative manner. Be safe and take care.