textproduct: Sioux Falls

KEY MESSAGES

- A Red Flag Warning is in effect for portions of southeast South Dakota, northwest Iowa, and northeast Nebraska from 11 am to 6 pm CST today. Strong winds and low humidity will create critical fire weather conditions. Report any fires to local authorities.

- Accumulating snow is expected late tonight into Saturday morning. Snow amounts from 1-3 inches are expected for areas mainly along and north of I-90. Locally higher amounts may fall in a narrower band along and east of the Buffalo Ridge.

- A more active weather pattern is expected Sunday into next week. While there is still a wide variation in forecast guidance, there will be multiple chances for precipitation. Precipitation type will depend on temperatures.

UPDATE

Issued at 215 AM CST Fri Feb 27 2026

High clouds across the area early this morning, with relatively mild temperatures in the 20s and 30s and breezy southerly winds. Based on obs, a boundary is located across the western portion of SD, which moves east today allowing winds to shift to the northwest. Main mid level wave is evident on satellite across eastern MT/ND. This moves south through tonight.

No changes to the Red Flag Warning, with very high fire danger across nearly the entire area today. Please see the Fire Weather Section of this discussion. Use extreme caution to prevent fire start and report any fires to local authorities. Breezy northwesterly winds gust to 40 mph today. Temperatures warm into the 50s and 60s.

Still expect an area of snowfall to develop with the wave and move into the forecast area after midnight. 27.00z and 06z guidance continues to show some variety in where the heaviest band sets up, but generally still expecting 1-3" of snow along and north of a Huron to Sioux Falls to Spencer line, with the highest amounts in southwestern MN. Some locations may see higher amounts in a very narrow band, and if these trend upward, areas along/east of the Buffalo Ridge may need a Winter Weather Advisory. The 06z HRRR has shifted nearly all of the snow to the north and east of our area, so may actually see amounts trend back down if this solution is realized. Snow tapers off quickly from west to east through the morning and early afternoon Saturday, with more seasonable temperatures.

Guidance continues to show a more active pattern through at least the early part of next week with multiple waves trekking through the synoptic northwesterly flow - leading to periodic light precipitation chances Sunday and again Monday/Tuesday. No changes to the NBM at this time due to timing/track issues and lower confidence, as well as focus on the short term forecast. Regardless of any snow chances, seasonal temperatures remain in place through at least early next week.

DISCUSSION

Issued at 220 PM CST Thu Feb 26 2026

Currently watching several observation sites flirt with Red Flag Warning criteria. While RH has dropped below 30 percent for much of the area and some spots below 20-25 percent, there have been hour to hour fluctuations in winds. Would like to see a more consistent higher end wind to justify the issuance of a headline. Will cover these near critical conditions with a Special Weather Statement through the afternoon. Conditions should improve rapidly after sunset as surface winds decouple and humidity increases.

Attention then turns to tomorrow. Another warm, dry, and breezy day. See the Fire Weather section below for more details.

A potent short-wave in northwest flow then drops south across the southern Canadian Prairies on Friday with its attendant surface cold front moving through the forecast area Friday night into Saturday. Along this frontal boundary, expect the development of some light snow. All guidance is showing a band of snow oriented northwest to southeast across SD/MN/IA, but there are differences in exact placement. A blended solution suggests the area most likely to see accumulating snow along and north of I-90. Right now, 1-2 inches seem reasonable, although model soundings show several hours of a saturated profile within the dendritic growth zone. This may lend to a narrower band of higher snow that may require winter headlines. Highs Saturday will range from near 20 degrees along the Buffalo Ridge to the mid-30s along the Missouri River Valley.

Continued cold into Sunday with another chance for light snow as a more subtle wave moves through northwest flow aloft. 12Z model suite is split with the GFS/NAM farther south with any precipitation and the ECMWF/GEM a bit farther north. Moisture is not as impressive with this wave, so any accumulation appears minimal.

Temperatures moderate into next week with a fairly significant change in the 500 hPa synoptic pattern. There's agreement in large scale troughing across the western CONUS, but wide variation in when and how strong any individual waves lift northeastward into the Northern Plains. At this time, temperature profiles suggest above freezing values during the day and below freezing at night. Therefore, precipitation type will be highly dependent on time of day. For now, NBM broad brushed 20 to 40 POPs for next week seem reasonable.

AVIATION /06Z TAFS THROUGH 06Z SATURDAY/

Issued at 1045 PM CST Thu Feb 26 2026

VFR conditions are expected for the TAF period. Light west/southwest winds remain this evening and will persist through the overnight hours. Some low level wind shear (LLWS) is expected for a few hours during the morning timeframe tomorrow. Winds will then restrengthen out of the northwest for the afternoon hours with gusts up to 25-35 knots. The winds will be weakening to end the TAF period. Clouds cover will be increasing aloft towards the end of the TAF period in response to incoming snow. However, any snow that does fall looks to come after the TAF period ends.

FIRE WEATHER

Issued at 215 AM CST Fri Feb 27 2026

Very high fire danger today over nearly the entire area with northwesterly wind gusts up to 40 mph. Maintained the previously issued Red Flag Warning where confidence is highest in RH values around and below 20%. If RH values fall a bit more than expected due to mixing down drier air, the Red Flag Warning may need to be expanded a row or two of counties northward where minimum RH values are currently expected to be around 30%. Greatest threat for critical fire conditions remains from 11 AM CST to 6 PM CST, with winds dropping off quickly after sunset. Near critical fire danger is possible outside of the Red Flag Warning. Report fires to local authorities and prevent fire start - fires will spread quickly today.

Cooler temperatures and precipitation chances temper fire danger into early next week, despite periodically breezy conditions. Minimum RH values remain above 35%.

FSD WATCHES/WARNINGS/ADVISORIES

SD...Red Flag Warning from 11 AM this morning to 6 PM CST this evening for SDZ050-057>059-063>071. MN...None. IA...Red Flag Warning from 11 AM this morning to 6 PM CST this evening for IAZ012-020-021-031-032. NE...Red Flag Warning from 11 AM this morning to 6 PM CST this evening for NEZ013-014.