We're at 74.9" of snowfall at MSP Airport so far this winter.
This is already the 10th snowiest winter on record.
We're now ahead of the pace for the snowiest winter on record which was 98.6" back in 1983-'84.
Last weekend's blockbuster storm was also the biggest February snowfall on record for the Twin Cities.
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!)
-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.
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 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.
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.
As arctic air slides into the region, the forecast models for the weekend bear watching.
A split flow in the upper atmosphere and an active southern branch of the jet stream is spawning potential snow system. The flow is chaotic, something the forecast models don't handle very well. The big question is how far north these southern disturbances will project snow.
Major model differences:
There are some pretty remarkable differences and "divergent solutions" between the models regarding the weekend forecast at this point. Depending on which model turns out to be right, Saturday could either be sunny and cold, or cloudy with steady light snow adding up to 1" to 3" for much of southern Minnesota.
Sunday into Monday could either feature a storm sliding south and producing significant snowfall for Wisconsin or Chicago, or veer north and sideswipe southeast Minnesota (and possibly even the metro) with a shot of snow.
Right now I'm leaning toward a solution which features just a chance of light snow Saturday, with the bulk of a southern branch storm sliding southeast of Minnesota Sunday into Monday.
But stay tuned for updates as the modles (hopefully) sort things out Friday....
Could NWS funding cuts affect forecast accuracy in Minnesota?
There is big talk in Washington these days about proposed budget cuts for NOAA and the National Weather Service. Some proposals cut the NWS budget by about 30%.
Suggested impacts of such cuts could include closing NWS offices (there was already consolidation years ago which closed the NWS office in International Falls) reducing maintenance on the doppler radar and NOAA weather radio networks and even reducing the number of upper air soundings from every 12 hours to once daily or even once every two days.
While I don't always jump on the NWS bandwagon, it is clear to me this is not the place to start cutting budgets. Studies have shown that accurate weather forecasts save the U.S. economy as much as 4-billion dollars annually! Most of this data comes directly in one form or another from NOAA & NWS.
One area where we might see an immediate catastrophic forecast impact would be if either the number or frequency of upper air soundings is reduced. These twice daily soundings are used as initial input into numerical forecast models that we use every day to make our weather forecasts.
If the geographic coverage or frequency of upper air data input feeding into the models is reduced, it would likely drastically affect model performance.
One area that could wreak havoc for Minnesota is on model performance for winter storms.
Many of our major winter storms cross the Pacific before moving into the upper air weather balloon "grid" over North America. Once the systems get "sampled" by the upper air grid, the models have much better data on storm strength, movement and thermal profile...all of which are critical in determining how much rain or snow will fall in Minnesota, and where.
This is why you've heard me talk about the futility of trying to predict snowfall totals more than 24 to 48 hours in advance. The forecast models just don't have enough accurate data on the storm until the system moves over the west coast!
If we had to wait even longer to sample storms coming off the Pacific it could be a disaster on model accuracy with winter storms. Forecasting winter storms is already one of the most difficult forecasts a meteorologist in Minnesota has to make. I can't imagine how much worse the projections would be without accurate and timely upper air data feeding into the models every 12 hours!