textproduct: Sioux Falls

KEY MESSAGES

- Blizzard conditions are expected north of I-90 and especially into the Highway 14 corridor and southwest Minnesota this evening through Sunday. Snowfall rates greater than an inch per hour are likely in these areas and wind gusts up to 55 mph will lead to dangerous road conditions.

- For the area along and south of I-90, lighter snow amounts are expected. However, given the potential for gusts up to 60 mph in these areas, blizzard conditions are possible even in light snow. A Winter Storm Watch remains in effect for these areas, but upgrades in the near future may be necessary as confidence in the wind forecast increases.

- Dry conditions and a warming trend is expected for the second half of next week.

UPDATE

Issued at 246 AM CDT Sat Mar 14 2026

A band of light snow stretches from roughly Wessington Springs, SD to Sioux Falls, SD to Spencer, IA and will be slowly lifting northward through daybreak today. The snow has been fighting with some dry air especially with eastward extent, but additional amounts will be generally less than inch near and north of I-90, but a few spots towards Highway 14 in central South Dakota could see up to an inch and a half. This band of snow will clear the area to our north by the late morning/early afternoon today, allowing for highs tomorrow to range from the upper 30s north to middle 50s south. This may melt off most of the snowfall especially given the higher March sun angle, but our next round of snow will be knocking on our door right after this melting.

Even though snowfall totals have trended down with the latest guidance showing the track of the system shifting slightly north, strong winds are still expected to cause major impacts no matter how much snow your location ends up receiving. With that said, the highest totals are still expected north of I-90 and especially closer to Highway 14 and into southwest Minnesota where snowfall totals could push the double digits. For this reason, along with gusts up to 55 mph here, a Blizzard Warning has been issued for these locations this evening through Sunday night. Significant impacts to travel are expected as whiteout conditions are likely in these areas, so stay home if you can, but if you must travel, be extremely cautious. Lower confidence in blizzard conditions farther south where snowfall amounts will likely be much lower, so held off on any upgrades for the Winter Storm Watch along and south of I-90. Based on the current forecast of wind gusts of 40 to 60 mph heading into the day on Sunday, blizzard conditions would be likely even with light amounts, but will give it a little more time before any upgrades in case winds trend down for any reason. Also, these potential blizzard conditions are still over 24 hours out, leaving a little more wiggle room to allow for increased confidence before any upgrade. Did adjust the timing slightly later for the start of the Winter Storm Watch to account for when winds are expected to increase.

One last note on the precipitation with this system, some areas may start as rain this evening, and before this turns to snow, some freezing rain or sleet may mix in. This would likely be brief, but may be enough to lead to a light glaze of ice over parts of eastern South Dakota, southwest Minnesota, and northwest Iowa. Ice amounts will be largely dependent on where the freezing line sets up and how much sleet can mix in, but be sure to keep up to date with the latest forecast to remain informed on this potential. Winds look to start slowly decreasing through the day on Monday, but wind chills look to drop to the negative 10s to negative 20s Monday morning, so be sure to bundle up. Considerations for cold weather headlines may be necessary in the near future, but will get through the worst of the blizzard conditions first. Also be prepared for the potential for continued drifting of the snow primarily into southwest Minnesota during the Monday morning commute. It stays much below average into Tuesday morning, with a gradual warming trend expected through the end of the week as strong ridging builds in from the west.

DISCUSSION

Issued at 408 PM CDT Fri Mar 13 2026

Light WAA showers are moving southeast from western South Dakota. Soundings indicate a stout dry subcloud layer that will take some time to saturate before any precipitation will reach the surface. While a few light sprinkles to flurries are possible yet this afternoon, the most likely scenario is light snow will not begin until around midnight. Light snow gradually increases in areal coverage mostly along I-90 and north, gradually moving northeast through Saturday morning. There is potential for a slightly heavier band to set up as a 700 mb frontogenesis band takes shape. This band is most likely to form along a rough line from Huron, to Madison, to Luverne MN. Within this band 1 to 2 inches of accumulation is possible. Elsewhere an inch or less is expected, with areas south of I-90 seeing only a dusting to a tenth or two. Snow tapers off Saturday afternoon.

Meanwhile an upper wave begins to take shape over the Pacific Northwest. This wave moves east and digs south through the day Saturday, with the surface low ejecting out of Wyoming into the central Plains. As it progresses northeast an area of strong WAA will push our highs into the 30 to 40s north of I-90, and the 40s to 50s to the south. As the system continues northeast positive vorticity advection increases and works to amplify divergence aloft. The resulting band of intensifying frontogenesis in the 700 mb layer will trigger precipitation to form along and north of Highway 14 Saturday afternoon. Precipitation may begin as snow or a wintry mix, but change to rain as it sinks south into warmer temperatures. Rain eventually transitions to a wintry mix then to all snow after midnight. As the system pivots to the southeast snow will begin to intensify. Moderate to heavy snow is possible from around midnight through Noon on Sunday. Snow gradually tapers off from west to east Sunday afternoon, pushing east of the region Sunday evening. Total snowfall remains uncertain. As mentioned in a prior update, the track of the storm has shifted slightly north with the past couple of model runs, but has held steady with the 12Z run today. If the northward shift continues snow totals will come down a little more. However, if the model trends of the past few years holds, there will be another shift southward in track at 24-36 hours out. While I have adjusted totals for the current model run, I kept them minimal.

There are several threats we need to take into consideration Saturday night and Sunday. First, portions of northwest Iowa and southwestern Minnesota may see a light glaze to a few hundredths of ice accumulation before the transition to all snow.

Second, winds will become northerly behind the front. Strong CAA in the 925-850 mb layer will result in rapidly increasing, strong wind gusts Sunday. After collaboration with neighbors, have boosted winds with a 66% NBM and 33% NBM90 blend. Gusts of 45-55 mph are expected with occasional gusts to 60 mph possible. This will result in blowing and drifting snow. Visibility may decrease to less than 1/4 of a mile at times, and travel may become difficult to impossible due to blowing and drifting snow. Near blizzard to blizzard conditions are expected for portions of east central South Dakota and southwestern Minnesota. Considering the risks for ice and snow, a Winter Weather Advisory is in effect from 7 pm Saturday until 7 am Monday. Due to remaining uncertainty in track have foregone a blizzard warning at this time, however an upgrade will likely be necessary. If you have travel plans this weekend, please ensure you have an alternative in mind and that your vehicle is prepared for winter travel.

Third, wind chills will be very cold Monday morning, falling to minus 20 to minus 25. Wind chills will improve during the day but will remain near to sub-zero through Tuesday morning.

Monday will be dry but cold, with highs around 10-20 degrees F. Monday night lows will fall to the single digits either side of zero. Chances for snow return Tuesday afternoon, but are expected to be light. Highs will be slightly warmer, in the 30s to 40s with the warmest temperatures over south central South Dakota. The remainder of the week should be dry with a nice warming trend into the 40s and 50s Wednesday and Thursday, and 50s to 60s Friday.

AVIATION /18Z TAFS THROUGH 18Z SUNDAY/

Issued at 1254 PM CDT Sat Mar 14 2026

Broken to overcast mid-level clouds will gradually fill in through the afternoon ahead of a strong incoming winter storm. Breezy southeasterly winds gusting 25-30 kts will become easterly late this evening, and northerly overnight behind a cold front. After midnight gusts will begin to increase in response to the passage of the front, gusting 30-35 kts. Gusts continue to increase through Sunday morning, peaking mid-morning between 45-50 kts. A Blizzard Warning is in effect tonight through Monday morning when winds begin to gradually subside.

Light rain/snow moves into the area along Highway 14 this evening. As it continues to push south of I-90 the main precipitation type will be rain, with some thunder possible over northwestern Iowa. After midnight the rain begins to transition to a wintry mix to all snow from north to south. By Sunrise precipitation will be all snow and blowing snow. Snow may be heavy at times, 1+ inch/hour. Rapidly accumulating and blowing snow is likely to impact flight operations at all three TAF sites. Snow tapers off through Sunday afternoon from west to east. However, the blowing snow risk will continue into Monday morning.

Ceilings and visibility will degrade from VFR down to IFR and possible LIFR at times under heavy snow. These conditions will continue beyond the end of the period.

FSD WATCHES/WARNINGS/ADVISORIES

SD...Winter Storm Watch from late tonight through Monday morning for SDZ062-066-067. Winter Storm Watch from Sunday morning through Monday morning for SDZ068>071. Blizzard Warning from 10 PM this evening to 7 AM CDT Monday for SDZ040-056. Blizzard Warning from 10 PM this evening to 1 AM CDT Monday for SDZ038-039-052>055. Winter Storm Watch from 7 PM to 10 PM CDT this evening for SDZ050-057>061-063>065. Winter Storm Watch from late tonight through late Sunday night for SDZ050-057>061-063>065. MN...Winter Storm Watch from late tonight through Monday morning for MNZ098. Blizzard Warning from 10 PM this evening to 7 AM CDT Monday for MNZ071-072-080-081-089-090-097. IA...Winter Storm Watch from late tonight through Monday morning for IAZ001. Winter Storm Watch from Sunday morning through Monday morning for IAZ002-003-012>014-020>022-031-032. NE...Winter Storm Watch from Sunday morning through Monday morning for NEZ013-014.