February 12, 2020 Blizzard

Wind:

Observed Maximum Wind Gusts (between 6 PM Tuesday to 6 PM Wednesday)

Site Specific Max Wind Gusts

Snow

Overall, this blizzard brought very little snowfall, and the snow that did fall was immediately blown around by the strong winds. This made obtaining an accurate snowfall measurement nearly impossible! Because of this, we use the WRS-88D radar network to get an estimate of snowfall. Below is a snowfall estimate from Tuesday evening through mid day Wednesday. 

Temperature & Wind Chill

The cold air surging southward brought bitterly cold temperatures and absolutely frigid wind chills. Here's a look at the coldest wind chills and temperatures from across the region. 

Minimum Wind Chills (between 6 PM Tuesday to 6 PM Wednesday)

Site Specific Minimum Temperatures (6 PM Wednesday to 9 AM Thursday)

Photos 

Semi wreck on MN Highway 75 in Kittson Co.  (MN State Highway Patrol)	Semi wreck on I-94 near exit 15.  (MN State Highway Patrol)	Semi wreck near Fargo. (ND Highway Patrol)	MN Highway 10 near Dilworth, MN around 9 AM (MN DOT)

Zero visibility just west of Fargo. (ND Highway Patrol)	Low visibility west of Grand Forks.  (ND DOT)	Blowing snow/blizzard conditions visible from the GOES-16 satellite. (NOAA/NWS)	US Highway 2 near Fisher, MN around 9 AM (MN DOT)

Environment

The 12 February blizzard was primarily driven by a very strong pocket of arctic air surging southward behind a weak mid level wave that was moving southward out of Canada. This wave can been seen in the mid and upper level analyses (Figures 1-3) while the surge of cold air is easily located across the northern Plains in Figure 6. 

This event produced little in the way of snowfall, mainly because of weak synoptic lift and an unfavorable mean flow regime for bringing moisture into the region. However, the strengthening cold front drove frontogenetical snowfall along and just ahead of the cold front that resulted in 0.5 to 1.5 inches of snowfall. Snowfall rates were actually fairly high for this event (up to one inch per hour), but due to the quick progression of the front the snow had very short residence time and therefore did not break heavier snowfall amounts. 

The more impressive component to this blizzard was the strong winds. This event exemplified an ideal high-wind scenario and ground blizzard set up for the Red River Valley: 

1) There was very strong cold air advection (Grand Forks, ND saw temperatures fall at a rate of 4.6 F/hour - Figure 10). This drove low level lapse rates to steepen to nearly 8 C/km (Figure 7), which in turn allowed stronger winds above the ground to mix downward to the surface. 

2) Wind direction was due north. This allows low level winds to strengthen through the Red River Valley due to the gradual rise in elevation (the up-slope flow causes adiabatic cooling which reinforces the temperature gradient and surface pressure rises and promotes stronger winds). 

3) There were strong pressure rises behind the cold front. Pressure rises on the order of 5-9 mb/3-hr drive strong isallobaric winds. Notice the rapid development of a surface high across the Northern Plains in Figure 9!

These conditions enabled strong winds to gust well into the 50-60 mph range and caused blowing snow across the region with lasting impacts through the immediate Red River Valley. 

A satellite analysis of this event can be found here.

Figure 1: 300 mb Analysis	Figure 2: 500 mb Analysis	Figure 3: 700 mb Analysis

Figure 4: 850 mb Analysis	Figure 5: 925 mb Analysis	Figure 6: Surface Analysis

Figure 7: Aberdeen, SD Soundings	Figure 8: Bismark, ND Soundings	Figure 9: International Falls, MN Soundings

Figure 10: Grand Forks Meteogram	Figure 11: Fargo Meteogram