Grade Summary
This storm was forecasted well overall. Models were consistent for almost a week with developing a major winter storm over the central Plains and tracking it east northeast to the Great Lakes. The forecast called for significant snowfall accumulations across southern and portions of eastern Minnesota and western Wisconsin for several days leading up to the event. It was clear there would be a sharp snowfall gradient. What made the forecast difficult was determining where it would set up. Slight run to run differences in modelling resulted in the gradient shifting north and south of the Twin Cities metro area. This decreased forecasters' confidence in its placement and prevented a depiction of a more realistic snowfall gradient in forecast graphics. However, it was stressed repeatedly through social media and official forecast products the placement of the gradient was the highest forecast uncertainty, and that drastic changes to the forecast may occur on local scales if it shifted one way or the other. Winter Storm Watches remained posted for the area near the gradient, while Winter Storm Warnings and Blizzard Warnings were issued earlier for the heart of the snow band. This messaging was well received by our customers. The storm moved in a bit slower than expected and a few points were deducted for timing.
Local conditions and perceptions may vary from the objective grade calculated below. Step through the other tabs to see a breakdown of the scoring.
|
91% |
Graded Element | Possible Points | Actual Points |
| 6 inch contour error | 8 | 7 | |
| Magnitude of snow error | 8 | 8 | |
| Onset timing error | 4 | 1 | |
| Peak wind gust error | 4 | 4 | |
| Probability of Detection/False Alarm Ratio | 8 | 8 | |
| Warning lead time | 8 | 8 | |
| Impact messaging | 4 | 4 | |
| Total | 44 | 40 | |
| Grade | 91% |
6 inch contour error
 |
 |
 |
| Official snowfall forecast at initial warning issuance |
Observed Snowfall (automatically generated graphic, with some interpolation and smoothing) |
Overlap of predicted and observed 6 inch snowfall areas |
| Error | Points |
| <=15 miles | 8 |
| 16-20 miles | 7 |
| 21-25 miles | 6 |
| 26-30 miles | 5 |
| 31-35 miles | 4 |
| 36-40 miles | 3 |
| 41-45 miles | 2 |
| 46-50 miles | 1 |
| 51+ miles | 0 |
| Actual: 16 miles | 7 |
Magnitude of snow error
The highest amount of snow forecast was around 15.5 inches near St. James, Minnesota. The actual highest total was 17.0 inches in Owatonna, MN and Winnebago, MN.
Forecast with initial warning issuance
Saturday afternoon, January 20, 2018:
|
 |
 |
 |
| Official snowfall forecast | Low end amount (90% chance for more snow than this) | Median amount (equal chances for more or less than this) | High end amount (10% chance for more snow than this) |
| Error | Points |
| <=2" | 8 |
| 2.1-3.5" | 6 |
| 3.6-5.0" | 4 |
| 5.1-6.5" | 2 |
| 6.6+" | 0 |
| Actual: 1.5" | 8 |
Subsequent Forecasts
Sunday morning, January 21, 2018:
 |
 |
 |
 |
| Official snowfall forecast | Low end amount (90% chance for more snow than this) | Median amount (equal chances for more or less than this) | High end amount (10% chance for more snow than this) |
Sunday afternoon, January 21, 2018:
 |
 |
 |
 |
| Official snowfall forecast | Low end amount (90% chance for more snow than this) | Median amount (equal chances for more or less than this) | High end amount (10% chance for more snow than this) |
Monday morning, January 22, 2018:
 |
 |
 |
 |
| Official snowfall forecast | Low end amount (90% chance for more snow than this) | Median amount (equal chances for more or less than this) | High end amount (10% chance for more snow than this) |
Snowfall reports by county:
Location Amount Time/Date
...Minnesota...
...Anoka County...
1 WNW New Brighton 11.9 in 0830 AM 01/23
2 N Circle Pines 10.0 in 1234 AM 01/23
2 SE Fridley 9.3 in 0630 PM 01/22
1 WNW New Brighton 9.0 in 1113 PM 01/22
3 N Blaine 7.1 in 0600 AM 01/23
Blaine 2NNW 7.1 in 0600 AM 01/23
1 SE Anoka 4.5 in 0700 AM 01/23
4 ENE East Bethel 3.0 in 0400 AM 01/23
2 W Stacy 2.5 in 0700 AM 01/23
...Blue Earth County...
Mankato 4E 13.7 in 0700 AM 01/23
2 WNW Eagle Lake 13.7 in 0700 AM 01/23
Mankato 13.0 in 0600 PM 01/22
1 NNE Madison Lake 11.5 in 0715 AM 01/23
Madison Lake 11.5 in 0715 AM 01/23
1 SW Amboy 10.0 in 0500 PM 01/22
...Brown County...
1 WSW New Ulm 9.0 in 0917 PM 01/22
New Ulm 7.5 in 0250 PM 01/22
2 NNW Springfield 4.8 in 0700 AM 01/23
...Carver County...
2 WSW Victoria 13.1 in 0700 AM 01/23
1 WSW Carver 12.7 in 0700 AM 01/23
NWS Chanhassen 11.0 in 0600 AM 01/23
Chaska 9.3 in 0620 AM 01/23
2 N Chaska 9.3 in 0620 AM 01/23
Waconia 8.6 in 0600 AM 01/23
1 NNW Watertown 5.5 in 0415 AM 01/23
...Chisago County...
4 S Shafer 10.0 in 0730 AM 01/23
Stacy 1W 2.5 in 0700 AM 01/23
1 NNE North Branch 2.0 in 0600 AM 01/23
...Dakota County...
Apple Valley 14.0 in 1207 AM 01/23
Burnsville 13.3 in 0901 PM 01/22
2 NE Northfield 13.2 in 0525 AM 01/23
2 S Inver Grove Height 13.1 in 0655 AM 01/23
4 NE Burnsville 13.0 in 0700 AM 01/23
Burnsville 3ENE 13.0 in 0700 AM 01/23
1 N Apple Valley 12.6 in 0100 AM 01/23
3 E Apple Valley 12.5 in 0540 AM 01/23
1 W Lakeville 12.2 in 0904 PM 01/22
2 WSW Eagan 11.6 in 0730 AM 01/23
Eagan 1NW 11.6 in 0730 AM 01/23
4 SE Eagan 11.5 in 0730 AM 01/23
Inver Grove Hgts 1WSW 11.5 in 0730 AM 01/23
2 SW Rosemount 11.0 in 0800 AM 01/23
Rosemount (AG Exp Frm) 11.0 in 0800 AM 01/23
4 E Apple Valley 11.0 in 0530 PM 01/22
3 W Rosemount 10.0 in 1058 AM 01/23
3 SE Apple Valley 10.0 in 0715 AM 01/23
Rosemount 3W 10.0 in 1058 AM 01/23
Rosemount 10.0 in 0730 PM 01/22
1 NW Hastings 9.0 in 0600 AM 01/23
Farmington 9.0 in 0330 PM 01/22
West St. Paul 7.6 in 0515 PM 01/22
...Faribault County...
Winnebago 17.0 in 0800 AM 01/23
1 WNW Winnebago 17.0 in 0800 AM 01/23
Blue Earth 13.0 in 1200 AM 01/23
1 E Blue Earth 12.5 in 0700 AM 01/23
1 WNW Wells 10.0 in 0349 PM 01/22
1 SSE Blue Earth 8.3 in 0800 AM 01/23
Blue Earth 1S 8.3 in 0800 AM 01/23
1 S Blue Earth 8.2 in 0600 PM 01/22
2 SW Bricelyn 3.5 in 0340 PM 01/22
Wells 3.0 in 0800 AM 01/23
...Freeborn County...
1 NW Albert Lea 10.0 in 0345 PM 01/22
Geneva 8.3 in 0515 PM 01/22
3 NNW Glenville 5.5 in 0800 AM 01/23
Twin Lakes 3.0 in 0515 PM 01/22
Glenville 3.0 in 0944 PM 01/22
...Goodhue County...
4 E Nerstrand 15.8 in 0700 AM 01/23
Goodhue 14.0 in 0500 PM 01/22
Cannon Falls 13.5 in 0350 PM 01/22
5 NNE Vasa 12.8 in 0700 AM 01/23
4 W Red Wing 12.7 in 0700 AM 01/23
Zumbrota 12.0 in 0130 PM 01/22
Pine Island 10.0 in 0115 PM 01/22
Red Wing 10.0 in 0445 PM 01/22
5 NW Red Wing 8.5 in 0600 AM 01/23
1 NE Red Wing 7.3 in 0800 AM 01/23
Zumbrota 7.0 in 0213 PM 01/22
12 ENE Bellechester 4.5 in 0700 AM 01/23
Lake City 1NNW 4.5 in 0700 AM 01/23
...Hennepin County...
2 N Richfield 13.5 in 0700 AM 01/23
MSP Airport 12.4 in 0600 AM 01/23
3 SSE Minneapolis 12.0 in 0900 AM 01/23
1 SSE Bloomington 11.8 in 0800 AM 01/23
Bloomington 1 ESE 11.8 in 0800 AM 01/23
2 SW Minneapolis 11.5 in 0500 AM 01/23
2 NNE Minneapolis 11.3 in 0700 AM 01/23
Edina 1SE 10.9 in 0700 AM 01/23
3 SSE Edina 10.9 in 0700 AM 01/23
Edina 10.8 in 0730 AM 01/23
2 N Golden Valley 10.0 in 0830 AM 01/23
1 S Columbia Heights 10.0 in 0130 AM 01/23
1 ESE Minneapolis 9.5 in 0600 AM 01/23
2 NW Minneapolis 9.5 in 1200 AM 01/23
3 E Richfield 9.3 in 0600 PM 01/22
1 W Richfield 9.3 in 0520 PM 01/22
1 ESE St. Louis Park 9.0 in 0945 PM 01/22
2 SSW Edina 9.0 in 0845 AM 01/23
Bloomington 9.0 in 0448 PM 01/22
Edina 1SW 9.0 in 0845 AM 01/23
Eden Prairie 3SE 8.1 in 0959 AM 01/23
2 ESE Eden Prairie 8.1 in 0959 AM 01/23
Golden Valley 8.0 in 0700 AM 01/23
1 NW Long Lake 8.0 in 0600 AM 01/23
1 SE Golden Valley 8.0 in 0700 AM 01/23
Long Lake 1NW 8.0 in 0600 AM 01/23
Long Lake 8.0 in 0700 AM 01/23
2 NNE Minneapolis 8.0 in 0600 PM 01/22
1 W Maple Grove 7.9 in 0600 PM 01/22
Plymouth 2ENE 7.8 in 0700 AM 01/23
2 W New Hope 7.8 in 0700 AM 01/23
1 NW Plymouth 7.5 in 0650 PM 01/22
Brooklyn Center 1E 6.9 in 0700 AM 01/23
1 N Minnetonka 6.5 in 0750 AM 01/23
Brooklyn Park 2E 4.6 in 0800 AM 01/23
2 ESE Brooklyn Park 4.6 in 0800 AM 01/23
Maple Grove 1N 3.1 in 1030 AM 01/23
1 N Maple Grove 3.1 in 1030 AM 01/23
...Isanti County...
Cambridge 0.8 in 0400 AM 01/23
Cambridge 3N 0.8 in 0700 AM 01/23
2 N Cambridge 0.8 in 0700 AM 01/23
...Le Sueur County...
Waterville 13.0 in 0230 PM 01/22
6 NNW Le Center 12.0 in 0800 AM 01/23
Kasota 7.5 in 0330 PM 01/22
...Martin County...
Fairmont 16.0 in 1200 AM 01/23
1 ESE Fairmont 13.5 in 0700 AM 01/23
Sherburn 12.0 in 0915 PM 01/22
1 ESE Fairmont 10.7 in 0700 AM 01/23
...McLeod County...
2 SSW Lester Prairie 5.5 in 0700 AM 01/23
Glencoe 4.0 in 0800 AM 01/23
6 N Hutchinson 2.0 in 0600 AM 01/23
2 N Silver Lake 1.3 in 0700 AM 01/23
Silver Lake 1NNW 1.3 in 0700 AM 01/23
...Nicollet County...
Lafayette 11.0 in 0630 AM 01/23
1 NE St. Peter 11.0 in 0745 AM 01/23
3 ESE New Ulm 9.0 in 0552 AM 01/23
1 SSW St. Peter 8.2 in 0500 PM 01/22
1 ESE Oshawa 4.0 in 0700 AM 01/23
St. Peter 6WSW 4.0 in 0700 AM 01/23
...Ramsey County...
3 S Falcon Heights 12.0 in 0630 PM 01/22
1 SE Falcon Heights 12.0 in 0930 PM 01/22
1 NW North St. Paul 12.0 in 0700 AM 01/23
1 NNW North St. Paul 11.8 in 0900 AM 01/23
2 W Vadnais Heights 11.0 in 0109 AM 01/23
2 S Maplewood 10.0 in 1200 AM 01/23
3 SSE Maplewood 9.8 in 0540 PM 01/22
1 SE Mounds View 9.7 in 0931 PM 01/22
2 SSE New Brighton 8.0 in 0600 AM 01/23
2 NW Roseville 7.9 in 0700 AM 01/23
Roseville 1NW 7.9 in 0700 AM 01/23
...Redwood County...
1 NE Redwood Falls 1.5 in 0530 AM 01/23
...Renville County...
7 SSE Bird Island 0.8 in 0700 AM 01/23
Bird Island 7SSE 0.8 in 0700 AM 01/23
...Rice County...
1 N Faribault 13.0 in 0700 AM 01/23
1 WNW Veseli 13.0 in 0500 AM 01/23
Northfield 12.5 in 0215 PM 01/22
Faribault 12.0 in 0230 PM 01/22
3 ENE Montgomery 8.5 in 0430 AM 01/23
...Scott County...
2 WNW Prior Lake 16.6 in 0700 AM 01/23
Prior Lake 15.5 in 0653 PM 01/22
1 SE Belle Plaine 13.5 in 0834 PM 01/22
5 NNE Veseli 13.0 in 0700 AM 01/23
Jordan 12.8 in 0823 PM 01/22
1 WSW Savage 11.9 in 0837 PM 01/22
...Sherburne County...
1 SW Elk River 2.0 in 0730 AM 01/23
1 WSW Elk River 1.3 in 0600 AM 01/23
1 SSW Zimmerman 0.4 in 0800 AM 01/23
3 SE Orrock 0.1 in 0700 AM 01/23
...Sibley County...
6 SE Green Isle 9.0 in 1120 AM 01/23
6 N Henderson 9.0 in 1120 AM 01/23
1 NNW Winthrop 5.5 in 0906 PM 01/22
...Steele County...
2 NE Owatonna 17.0 in 0538 PM 01/22
1 ENE Owatonna 15.1 in 0630 AM 01/23
Owatonna 15.1 in 0630 AM 01/23
Ellendale 15.0 in 0926 PM 01/22
1 ENE Owatonna 14.8 in 0630 AM 01/23
...Waseca County...
Waseca 16.5 in 0400 PM 01/22
...Washington County...
Cottage Grove 13.0 in 0900 AM 01/23
1 NE Woodbury 12.0 in 0700 AM 01/23
Stillwater 2 SW 11.4 in 0600 AM 01/23
2 SSW Stillwater 11.4 in 0600 AM 01/23
Stillwater 11.0 in 0852 PM 01/22
Mahtomedi 10.0 in 0117 AM 01/23
Cottage Grove 9.0 in 0646 PM 01/22
St. Paul Park 9.0 in 0430 PM 01/22
1 NE Woodbury 8.8 in 0500 PM 01/22
Stillwater 1NE 7.5 in 0846 AM 01/23
1 NNE Stillwater 7.5 in 0846 AM 01/23
1 NNE Lake Elmo 7.0 in 0538 PM 01/22
Afton 1E 7.0 in 0845 AM 01/23
...Watonwan County...
Madelia 12.0 in 0515 PM 01/22
St. James 12.0 in 0230 PM 01/22
1 ENE St. James 10.0 in 0115 PM 01/22
...Wright County...
Rockford 2.9 in 0700 AM 01/23
2 WNW Dayton 2.5 in 0745 PM 01/22
1 NNW Albertville 2.1 in 0600 AM 01/23
Buffalo 1.7 in 1256 AM 01/23
St. Michael 1E 1.5 in 0800 AM 01/23
1 SSW St. Michael 1.5 in 0800 AM 01/23
1 E St. Michael 1.4 in 0630 AM 01/23
St. Michael 2ENE 1.4 in 0630 AM 01/23
...Wisconsin...
...Barron County...
2 SE Chetek 13.0 in 0700 AM 01/23
1 E Barron 11.5 in 0900 AM 01/23
Barron 10.0 in 0700 AM 01/23
Rice Lake 9.2 in 0800 AM 01/23
1 NW Cameron 9.2 in 0800 AM 01/23
Cumberland 8.5 in 0700 AM 01/23
1 NE Ridgeland 8.0 in 0700 PM 01/22
Haugen 9.0 in 0600 AM 01/23
...Chippewa County...
4 N Altoona 11.5 in 0430 AM 01/23
3 E Chippewa Falls 10.3 in 1000 AM 01/23
1 WSW Chippewa Falls 10.2 in 0800 AM 01/23
7 NE Tilden 8.8 in 0415 AM 01/23
Holcombe 8.0 in 0700 AM 01/23
4 N Cornell 8.0 in 0700 AM 01/23
Bloomer 7.0 in 0800 AM 01/23
4 W Cornell 5.0 in 0800 AM 01/23
...Dunn County...
Downsville 10.5 in 0810 AM 01/23
Menomonie 9.5 in 0745 AM 01/23
Elk Mound 9.5 in 1130 AM 01/23
1 SW Menomonie 9.5 in 0700 AM 01/23
Cedar Falls 7.0 in 0700 AM 01/23
Cedar Falls (Hydro) 7.0 in 0700 AM 01/23
...Eau Claire County...
4 SSE Elk Mound 11.0 in 1000 AM 01/23
Eau Claire 1WNW 8.5 in 0500 AM 01/23
2 WNW Eau Claire 8.5 in 0500 AM 01/23
6 SW Fall Creek 8.5 in 0845 AM 01/23
Eau Claire 7.0 in 0600 AM 01/23
Augusta (RS) 6.1 in 0800 AM 01/23
1 W Augusta 6.1 in 0800 AM 01/23
...Pepin County...
Stockholm 2NE 7.5 in 0800 AM 01/23
3 NE Stockholm 7.5 in 0800 AM 01/23
...Pierce County...
Prescott 14.1 in 0700 AM 01/23
1 NW Prescott 14.1 in 0700 AM 01/23
5 WSW Bay City 12.0 in 0730 AM 01/23
1 SW River Falls 7.0 in 0700 AM 01/23
1 E Ellsworth 7.0 in 0246 PM 01/22
Ellsworth 7.0 in 0300 PM 01/22
...Polk County...
5 SSE Balsam Lake 6.0 in 0700 AM 01/23
3 E Nye 4.0 in 0800 AM 01/23
...Rusk County...
Glen Flora 12.5 in 1050 PM 01/22
Big Falls Hydro (Flambeau R) 11.0 in 0700 AM 01/23
6 NW Glen Flora 11.0 in 0700 AM 01/23
3 WNW Ladysmith 10.3 in 0700 AM 01/23
Ladysmith 9.5 in 0700 PM 01/22
2 ESE Bruce 8.5 in 0700 AM 01/23
Hawkins 8.0 in 1000 AM 01/23
1 WNW Tony 8.0 in 1000 AM 01/23
...St. Croix County...
1 WSW Baldwin 12.5 in 0700 AM 01/23
1 SSE Somerset 12.0 in 0100 AM 01/23
4 S Clear Lake 11.5 in 0552 PM 01/22
Hudson 11.0 in 0745 PM 01/22
3 E Hudson 9.8 in 0615 PM 01/22
1 NNW Somerset 9.0 in 0500 PM 01/22
1 SSW Roberts 8.7 in 0800 AM 01/23
Roberts 8.7 in 0800 AM 01/23
New Richmond 1SW 7.5 in 0800 AM 01/23
2 SSW New Richmond 7.5 in 0800 AM 01/23
4 S Clear Lake 2.4 in 0930 AM 01/23
Observations are collected from a variety of sources with varying
equipment and exposures. We thank all volunteer weather observers
for their dedication. Not all data listed are considered official.
Onset timing error
The time visibility falls to less than 3 miles due to falling snow is noted for each warned weather station at an airport. This is considered the time accumulating snow begins. It is checked against the time snow becomes likely in the forecast and the difference is calculated. The expected time range will never be greater than 3 hours.
| Warned Airport Weather Station | Expected time accumulating snow becomes likely | Actual time visibility fell to less than 3 miles due to snow | Error (hh:mm) |
| Albert Lea (AEL) | 12:00-3:00 am | 2:15 am | 0:00 |
| Blaine (ANE) | 6:00-9:00am | 10:28 am | 1:28 |
| Chetek (Y23) | 3:00-6:00 am | 11:18 am | 5:18 |
| Crystal (MIC) | 6:00-9:00 am | 10:20 am | 1:20 |
| Eau Claire (EAU) | 3:00-6:00 am | 8:40 am | 2:40 |
| Fairmont (FRM) | 9:00 pm (Sun) -12:00 am (Mon) | 3:45 am | 3:45 |
| Faribault (FBL) | 12:00-3:00 am | 6:15 am | 3:15 |
| Eden Prairie (FCM) | 6:00-9:00 am | 4:35 am | 1:25 |
| Lake Elmo (21D) | 6:00-9:00 am | 10:35 am | 1:35 |
| Lakeville (LVN) | 12:00-3:00 am | 7:35 am | 4:35 |
| Mankato (MKT) | 12:00-3:00 am | 6:20 am | 3:20 |
| Menomonie (LUM) | 3:00-6:00 am | 9:55 am | 3:55 |
| Minneapolis/St. Paul (MSP) | 6:00-9:00 am | 10:04 am | 1:04 |
| New Richmond (RNH) | 3:00-6:00 am | 11:15 am | 5:15 |
| New Ulm (ULM) | 12:00-3:00 am | 6:55 am | 3:55 |
| Oscelola (OEO) | 6:00-9:00 am | 10:55 am | 1:55 |
| Owatonna (OWA) | 12:00-3:00 am | 5:35 am | 2:35 |
| Red Wing (RGK) | 12:00-3:00 am | 8:55 am | 5:55 |
| Redwood Falls (RWF) | 12:00-3:00 am | 10:05 am | 7:05 |
| Rice Lake (RPD) | 3:00-6:00 am | 11:35 am | 5:35 |
| South St. Paul (SGS) | 3:00-6:00 am | 10:35 am | 4:35 |
| St. James (JYG) | 12:00-3:00 am | 6:15 am | 3:15 |
| St. Paul (STP) | 6:00-9:00 am | 9:40 am | 0:40 |
| Stanton Airfield (SYN) | 12:00-3:00 am | 7:55 am | 4:55 |
| Waseca (ACQ) | 12:00-3:00 am | 5:35 am | 2:35 |
| Average: 3:16 |
| Error | Points |
| <1 hr | 4 |
| 1-2 hr | 3 |
| 2-3 hr | 2 |
| 3-4 hr | 1 |
| 4+ hr | 0 |
| Actual: 3:16 | 1 |
Peak wind gust error
| Warned Airport Weather Station |
Expected wind gusts from warning (mph) |
Actual wind gust (mph) |
Error (mph) |
| Albert Lea (AEL) | 40 | 41 | 1 |
| Blaine (ANE) | 35 | 31 | 4 |
| Chetek (Y23) | 35 | 25 | 10 |
| Crystal (MIC) | 35 | 30 | 5 |
| Eau Claire (EAU) | 35 | 37 | 2 |
| Fairmont (FRM) | 40 | 40 | 0 |
| Faribault (FBL) | 40 | 35 | 5 |
| Eden Prairie (FCM) | 35 | 36 | 1 |
| Lake Elmo (21D) | 35 | 37 | 2 |
| Lakeville (LVN) | 35 | 31 | 4 |
| Mankato (MKT) | 40 | 39 | 1 |
| Menomonie (LUM) | 35 | 36 | 1 |
| Minneapolis/St. Paul (MSP) | 35 | 35 | 0 |
| New Richmond (RNH) | 35 | 33 | 2 |
| New Ulm (ULM) | 40 | 31 | 9 |
| Oscelola (OEO) | 35 | 30 | 5 |
| Owatonna (OWA) | 40 | 39 | 1 |
| Red Wing (RGK) | 35 | 28 | 7 |
| Redwood Falls (RWF) | 35 | 33 | 2 |
| Rice Lake (RPD) | 35 | 35 | 0 |
| South St. Paul (SGS) | 35 | 27 | 8 |
| St. James (JYG) | 40 | 37 | 3 |
| St. Paul (STP) | 35 | 33 | 2 |
| Stanton Airfield (SYN) | 35 | 37 | 2 |
| Waseca (ACQ) | 40 | 46 | 6 |
| Average: 3 mph |
| Error | Points |
| <5 mph | 4 |
| 5-8 mph | 3 |
| 9-12 mph | 2 |
| 13-16 mph | 1 |
| 17+ mph | 0 |
| Actual: 3 mph | 4 |
Probability of Detection (POD)/False Alarm Ratio (FAR)
Probability of Detection (POD) is event-based, meaning that each confirmed event is checked to see if a warning was issued and in effect at the time of the event. The national goal for winter storms is 0.90 or greater (90%).
False Alarm Rates (FAR) are computed based on warnings. For each warning issued, did an event meeting warning criteria take place? There is not a set national goal for FAR. The higher the decimal, the more counties were warned for that didn't need them.
In this case, far southern Chisago county reached warning criteria, but a warning wasn't issued. Redwood county was warned for, but warning criteria wasn't met. The rest of the warning verified.
| POD | Points | FAR | Points | |
| 0.90+ | 4 | <0.11 | 4 | |
| 0.80-0.89 | 3 | 0.11-0.20 | 3 | |
| 0.70-0.79 | 2 | 0.21-0.30 | 2 | |
| 0.60-0.69 | 1 | 0.31-0.40 | 1 | |
| <0.60 | 0 | 0.40+ | 0 | |
| Actual: 0.97 | 4 | Actual: 0.03 | 4 |
Warning lead time
Lead time is considered the amount of time between the warning issuance and when criteria is met (typically when 6 inches of snow was measured). This category is the average lead time of all the verified counties.
| Lead Time | Points |
| 20+ hours | 8 |
| 15-19 hours | 6 |
| 10-14 hours | 4 |
| 5-9 hours | 2 |
| <5 hours | 0 |
| Actual: 38.4 hours | 8 |
Impact messaging
The storm featured a very tight snowfall gradient that was difficult to forecast due to the uncertainty with where it would set up. Any slight shift north or south would result in drastic changes to the snowfall forecast near it. This was stressed repeatedly through social media and official forecast products. The watch was kept longer near the gradient than in areas solidly in the heavy snow band. The gradient was the main message in the media and with our partners. This messaging was well received.
Snowfall rates of 1 to 2 inches per hour were forecast for the afternoon, which was expected to lead to a very difficult evening commute. Many school districts under the Winter Storm Warning closed the day before the storm hit.
Blizzard Warnings were issued for south central Minnesota due to expected whiteout conditions. The Minnesota DOT advised no travel across this area and I-35 was closed between Faribault and Owatonna for a time due to whiteout conditions.
Feedback received was positive.
 |
 |
 |
| Impact messaging | Up to 4 points |
| Impacts were clearly conveyed and partners responded accordingly. Positive feedback was received. | 4 |
| Overall, impacts were conveyed well, but some impacts were underestimated. Mostly positive feedback was received. | 3 |
| Impacts could have been more clearly stated. Feedback was mixed. | 2 |
| Impacts were not clearly defined. Mostly negative feedback was received. | 1 |
| Impacts were opposite of what was forecast. Feedback was negative. | 0 |
| 4 |
 |
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