textproduct: Sioux Falls

KEY MESSAGES

- Light snow expected to arrive Tuesday afternoon. Moderate to high confidence of widespread light accumulations trace to 2", with potential for 3-4" in a corridor from Brookings to Windom.

- Light snow again Wednesday, but also potential for 30 to 45+ mph winds in the afternoon/evening. Winds could lead to significant blowing snow issues.

- Dangerous and life-threatening cold expected to arrive for the end of the week and start of next weekend.

DISCUSSION

Issued at 139 PM CST Mon Jan 19 2026

THIS Afternoon: High cloud cover continues to increase this afternoon as the nose of an upper jet streak enters the Plains. Despite filtered sunshine and weak warm advection, temperatures are slowly crawling through the single digits and into the teens.

TONIGHT: A weak impulse dropping through the Dakota may interact with a developing low-mid lvl baroclinic zone through the West River areas. Can't rule out a few flurries in the far western zones, but this brief chance is not expected to last very long in the night. Further east, skies will clear by late evening and continue to remain clear through at least 3am, potentially leading to clear viewing of potential aurora shows tonight. Lows will again fall below zero, but light winds will prohibit any wind chill headlines.

TUESDAY: The dominant long wave trough stretching over North America will send a fast moving area of vorticity into the Plains on Tuesday. Models are in reasonable agreement with this feature, but differ slightly on the amplitude and orientation of the energy as it pivots through South Dakota and Nebraska. The NAM and its derivatives maintain a stronger slightly positively tilted wave which induces strong focused warm advection through central and northern South Dakota and Minnesota through the afternoon and evening hours. These solutions also point to a slightly unstable parcel within the prime zone of lift between 850:700 mb. The result is a more focused band of 2-4" inches of snow north of I-90. The alternative solutions of the EC/CMC/GFS and their higher resolution derivatives are more open with the wave and less focused in low-lvl forcing instead relying on broad synoptic lift ahead of the wave to produce QPF. The result is more widespread light snow and generally lower amounts. The final forecast will represent a bit of a blend of the two scenarios, but hedging a bit more to the NAM/RAP/HRRR to indicate potential for modest banding. Snowfall totals may range from 0.5-3" especially north of I-90. Given light winds, will not issue any advisories, but if more guidance trends towards a sharper QPF resolution than a narrow advisory may be needed.

WEDNESDAY: Snow ends early Tuesday evening, leaving light westerly surface flow through the region ahead of yet another fast moving clipper moving through the upper trough. This second system has less moisture than Tuesday's wave, but unlike Tuesday's wave, may bring a much higher risk for stronger winds. Initial light bands of snow move through Wednesday morning, with a stronger cold front surging through in the afternoon. Soundings suggest that strong cold advection behind the front will sufficiently steepen low- lvl lapse rates to increase potential for 30 to 40 knot gusts. While snowfall isn't expected to be significant (Trace-1") the very fluffy snow that falls Tuesday may be easily blown around if these winds develop. At this time, the strongest corridor of winds may be through the MO river valley, hopefully steered away from Tuesday's snowfall.

THURSDAY-SATURDAY: The upper trough will continue to pinwheel around the Great Lakes region through the end of the week and into the upcoming weekend. A stronger upper low will dislodge from the arctic and begin to decent into the Great Lakes by Thursday. The resulting arctic front moves through the Plains Thursday afternoon and evening, bring gusty winds and blowing snow, but also the coldest air of the Winter season. The 1050+ surface high will drain arctic air southward into the weekend, resulting in greater than 70% probabilities of lows of -10 or colder and 30% probabilities of lows -20 or colder. Resulting wind chills are likely to fall well into advisory, if not into warning levels Friday and Saturday mornings. Realistically we'll need to watch both winds and temperatures (if fresh snow) for adjustments.

AVIATION /18Z TAFS THROUGH 18Z TUESDAY/

Issued at 1110 AM CST Mon Jan 19 2026

VFR conditions are expected into Tuesday morning. Occasionally breezy westerly winds this afternoon turn light and variable overnight. Skies clear after sunset, with a return of mid-lvl clouds by mid-morning Tuesday,

FSD WATCHES/WARNINGS/ADVISORIES

SD...None. MN...None. IA...None. NE...None.