textproduct: Sioux Falls

KEY MESSAGES

- A Fire Weather Watch remain in effect for the entire forecast area on Saturday. Critical conditions are expected. The potential for explosive fire growth is high. This is a potentially dangerous situation.

- Elevated to critical fire conditions remain the primary concern over the next several days with very dry fuels, breezy conditions, unseasonable warmth, and limited to no precipitation. Heed all burn bans and restrictions.

- While we will be dry to finish out the month, a pattern shift by early April could lead to renewed chances for rain and/or snow.

UPDATE

Issued at 314 AM CDT Fri Mar 27 2026

While slightly cooler, another breezy day is expected with gusts between 20-35 mph possible this afternoon. This combined with drier conditions will lead to elevated fire weather concerns especially along and east of Highway-81 (more in fire weather section). Besides that, the quiet and dry conditions will persist well into the weekend. With high-resolution guidance continuing to trend drier for Saturday, decided to blend some of the HRRR into the NBM dew points to further decrease RH values from late morning into the afternoon. Also slightly increased wind speeds by blending in some of the NBM 90th for the same time period. Otherwise, left our Fire Weather Watch in place for now.

DISCUSSION

Issued at 232 PM CDT Thu Mar 26 2026

Strong north winds will continue through this afternoon before gradually decreasing this evening. Due to the clouds and CAA have bumped highs down a few degrees from the NBM. Though relative humidity is expected to remain above critical values, the strong winds could still lead to rapid fire growth. Highs for today were met this morning in some areas. As of 2:30 pm CDT temperatures range from the 30s to low 50s. Lows tonight will be cold in the 20s.

Overnight there will be a brief lull in winds as they become light and variable. Around daybreak, a weak wave passes from North Dakota into Minnesota just to the north of our CWA. At the surface a weak surface low and cold front will move quickly through the region bringing another surge of CAA. This will work to enhance winds gusts at the surface, though they will not be as strong as today. Gusts of 20-30 mph are expected beginning around the morning commute, gradually tapering off through the early evening. More sun for Friday, but the cold air keeps our highs on the cool side of climatology in the 40s.

Friday afternoon an upper ridge builds in over the central US. At the surface high pressure will turn winds to the south and begin to increase after midnight. By mid-morning Saturday winds will be strong, sustained at 20-25 mph with gusts 35-40+ mph. Though winds will be strong, at this time they do not quite reach Wind Advisory criteria. Trends in the wind will be monitored over the next few forecast cycles to determine if a headline will be necessary in the future. Strong winds continue through the early afternoon, decreasing through the late afternoon and evening. In addition, subsiding air aloft and WAA will result in a warm and very dry conditions, with afternoon highs in the upper 50s to 60s. Relative humidity values are expected to fall to less than 20% for the majority of the region. Grassland Fire Danger Index will reach the Extreme category for the whole CWA. A Fire Weather Watch has been issued for Saturday. The details of the fire weather concerns are discussed in the Fire Weather Discussion below.

Sunday through Tuesday will continue to be warm, dry, and occasionally breezy. Highs will generally be in the 60s and 70s through this period. By Tuesday afternoon we begin to see a large upper trough taking shape over the Pacific Northwest. This brings our next chance of precipitation to the region mid-week. Rain and snow are possible beginning Wednesday and continuing into Thursday. Details are sparse at this time, so check back for updates.

AVIATION /06Z TAFS THROUGH 06Z SATURDAY/

Issued at 1140 PM CDT Thu Mar 26 2026

VFR through the period. Brief MVFR ceilings will be possible near KSUX and KSLB through about 8z. Northwest winds will gust around 25 mph on Friday.

FIRE WEATHER

Issued at 314 AM CDT Fri Mar 27 2026

Starting with today, northwesterly surface winds will gradually increase with mixing this morning eventually leading to gusts between 20-35 mph by this afternoon. While slightly offset from the strongest winds, dry air will filter into areas west of the James River Valley by midday then gradually spread northeastwards through the afternoon leading to relative humidity (RH) values in the 15-30 percent range with the lowest values across southcentral SD. While there will be some collocations of these values along and east of Highway-81 during the afternoon hours, high-resolution guidance continues to gradually weaken surface winds from west to east with the approach of a surface high by late afternoon. With this in mind, decided to forgo any fire- related headlines as the elevated to near-critical fire risk would be confined to a few short hours.

By Saturday, more widespread concerns are expected as a stronger push of warmer and drier air leads to RH values in the 12-20 percent range area-wide. This combined with deeper mixing and strong southwest winds in the 35-50 mph range will lead to critical fire weather concerns for all areas. With this in mind, our Fire Weather Watch looks to be in great shape. While a transition to a Red Flag Warning is almost certain at this point, we'll likely hold the watch for now as we deal with today's concerns and resolve a few more details. Nonetheless, it would be best to avoid burning on Saturday as the conditions could help a fire quickly spread out of control. Otherwise, high fire danger will again be possible by Sunday as RH values decrease into the 20-30 percent range. However, unlike the past few days; surface winds will be quite a bit lighter (10-20 mph) which should taper concerns.

FSD WATCHES/WARNINGS/ADVISORIES

SD...Fire Weather Watch from Saturday morning through Saturday evening for SDZ038>040-050-052>071. MN...Fire Weather Watch from Saturday morning through Saturday evening for MNZ071-072-080-081-089-090-097-098. IA...Fire Weather Watch from Saturday morning through Saturday evening for IAZ001>003-012>014-020>022-031-032. NE...Fire Weather Watch from Saturday morning through Saturday evening for NEZ013-014.