textproduct: Sioux Falls

KEY MESSAGES

- Strong south to southwest winds will develop this afternoon into the early evening. Gusts to 50 mph are expected in the higher elevations of south-central and east central South Dakota and southwest Minnesota.

- Strong cold front arrives Thursday morning bringing high winds and scattered snow. A High Wind Warning has been issued along and west of a Sioux City to Worthington to Marshall line, with a Wind Advisory to the east. Gusts of 55 to 60 mph will be common with isolated gusts to 70 mph possible in the warning.

- Potential for snow squalls continues Thursday morning, with impacts to visibility/travel possible into the afternoon due to continuing scattered snow showers. Where roads are still wet from tonight's rain, flash freeze conditions are also possible as temperatures quickly fall below freezing.

- Mild temperatures and mostly dry conditions are then expected into next weekend and the first portions of Christmas week.

DISCUSSION

Issued at 410 AM CST Wed Dec 17 2025

TODAY: Strong warm advection will be realized mostly aloft today, leading to a strengthening surface-based inversion that will limit 55-65+kt winds at 850mb from reaching the surface. However, our higher elevation area are expected to tap into the lower portion of this low-level jet, allowing stronger winds of 45 to 50 mph to mix to the surface. With such a sharp inversion, even slightly deeper mixing than expected could bring stronger winds to a broader area, so this will be monitored through the day. Did adjust today's Wind Advisory area to cover a bit more of the Coteau des Prairies in east-central SD, as well as to extend the expiration of the earlier segments (south-central SD and southwest MN) to 9 pm this evening as the strong winds look to persist beyond sunset.

TONIGHT: Scattered light rain showers are expected to develop during the late afternoon and early evening, with increasing coverage during the later evening to overnight as the elevated front and associated strengthening upper wave dig into the region. Temperatures remain in the mid 30s to lower 40s through the evening, then begin to fall toward freezing or below as the 850mb cold front pushes southeast after midnight. While the rain should be done falling when surface temperatures reach freezing or below, roads may still be wet from the nighttime rain and flash freeze conditions may develop Thursday morning.

THURSDAY: The morning commute and even into the later morning will present the most difficult travel conditions due to a combination of factors, mostly related to strong winds and falling temperatures. As mentioned above, a flash freeze of wet roads is possible as temperatures collapse through the 20s during the morning. The strong cooling will also tap into very strong winds aloft, with RAP soundings briefly showing 60-70kt winds atop of a deep mixed layer which also exhibits some convective instability. While not expecting 80 mph winds to reach the surface, gusts of 55 to 60 mph should expand across much of the forecast area Thursday morning with isolated gusts to 70 mph possible. These strongest gusts appear most likely in south- central South Dakota, but could briefly occur as far east as I-29. As such, the High Wind Watch has been transitioned to a High Wind Warning. While still strong, slightly lower wind gusts east of U.S. Highway 59 have prompted a Wind Advisory for the eastern portion of our forecast area.

In addition to the winds and flash freeze potential, scattered snow showers remain likely. Could see a broken band of snow showers along the leading edge of the 850mb cold advection, with high-res models indicating higher-end snow-squall potential which could impact portions of the morning commute. Even behind this leading band, the risk for scattered snow showers/flurries will linger as the trailing stratocu cools into a slightly unstable DGZ layer. Our warm temperatures have firmed up or melted the existing snow pack, so any impacts to visibility will be tied to falling snow within the strong wind field. As such, blizzard conditions are not expected as the falling snow should be scattered in nature. Instead, rapid changes in visibility are the more likely scenario, though that visibility could briefly drop below 1/2 mile at times, so motorists will want to remain aware of rapidly changing conditions.

FRIDAY ONWARD: Quasi-zonal flow aloft will keep any significant cold outbreaks at bay as we head into the Christmas holiday week, though fluctuations in temperature and occasional breezy days are likely. Precipitation chances are low this weekend into at least the first half of next week.

AVIATION /12Z TAFS THROUGH 12Z THURSDAY/

Issued at 552 AM CST Wed Dec 17 2025

Strong winds will be the primary aviation concern through this TAF period. Light early morning winds will increase out of the south this morning, with gusts 25-40+kt developing after 18Z. The strongest gusts are expected in higher elevations around the region, but our TAF sites should see occasional gusts 25-35kt.

These winds decrease slightly this evening, turning northwest and increasing again late tonight as a strong cold front moves east. Locations toward central SD could see gusts 45-50+kt by the end of this TAF period, with occasional gusts in excess of 50kt expanding east toward the I-29 corridor after 18/12Z.

VFR conditions should prevail through the period, though areas of light rain are expected to develop during the late afternoon and evening.

FSD WATCHES/WARNINGS/ADVISORIES

SD...High Wind Warning from 6 AM to 6 PM CST Thursday for SDZ039- 040-054>056-060>062-065>071. Wind Advisory from noon today to 9 PM CST this evening for SDZ040-050-057-063. Wind Advisory from noon today to 6 PM CST this evening for SDZ039-055-056. High Wind Warning from 3 AM to 6 PM CST Thursday for SDZ038- 050-052-053-057>059-063-064. MN...High Wind Warning from 9 AM to 6 PM CST Thursday for MNZ071- 072-080-089-097-098. Wind Advisory from 9 AM to 6 PM CST Thursday for MNZ081-090. Wind Advisory from noon today to 9 PM CST this evening for MNZ071-072-080-081-090. Wind Advisory from noon today to 6 PM CST this evening for MNZ097. IA...High Wind Warning from 9 AM to 6 PM CST Thursday for IAZ001- 012. Wind Advisory from 9 AM to 6 PM CST Thursday for IAZ002-003- 013-014-021-022-032. High Wind Warning from 6 AM to 6 PM CST Thursday for IAZ020- 031. NE...High Wind Warning from 6 AM to 6 PM CST Thursday for NEZ013- 014.