textproduct: Sioux Falls

KEY MESSAGES

- Warm and breezy conditions will lead to elevated fire danger in snow-free areas this afternoon. Thursday may see elevated to locally near-critical fire conditions as well.

- Above normal temperatures will dominate the week ahead with near record highs possible today. A few chances of light rain and/or snow with the better chances on Tuesday night, but no significant systems are expected.

UPDATE

Issued at 345 AM CDT Sun Mar 8 2026

Mild southwest flow has been keeping temperatures above freezing in most area early this morning, with 3 AM readings in the mid 30s to lower 40s common across the forecast area. A subtle wave and strong warm advection today will favor mixy westerly flow by this afternoon. Still a little snow yet to melt in portions of the Highway 14 corridor west of Brookings which could limit fire danger slightly in those areas. Otherwise this pattern favors strong mixing with much of the area reaching the 95th percentile of the Hot-Dry-Windy index. As a result, nudged temps/winds a little higher than the NBM, yielding near-record to record highs in the mid 60s to mid 70s and west winds gusting 25 to 35 mph. May still have to watch winds as RAP soundings show potential for gusts closer to 40 mph for areas along/east of the Buffalo Ridge this afternoon. The gusty winds and warm temperatures will drop humidity levels to 25 to 40 percent this afternoon, leading to Very High grassland fire danger for most of the area outside the lingering snow-cover.

No significant changes to the rest of the forecast period, which features above normal temperatures and dry conditions on most days. A midweek wave will bring a chance of mainly light snow Tuesday night, with some light accumulations possible (currently less than 20 percent probability of exceeding an inch).

Temperatures rebound quickly again on Thursday, with conditions slightly cooler than today, but still dry and breezy. Will again be looking at widespread Very High grassland fire danger, with greater potential for near-critical to critical conditions off to our southwest in western Nebraska.

DISCUSSION

Issued at 1257 PM CST Sat Mar 7 2026

Even with a little snowmelt and additional moisture in the boundary layer, fog looks unlikely tonight as a marginally tight surface pressure gradient with westerly flow should provide occasional mixing to help keep fog development at bay.

This stronger west to southwest flow at the surface will continue into Sunday and will likely aid in producing some elevated fire weather conditions. Soundings hint that a few locations could see some gusts around 40 mph, with 25 to 35 mph gusts to most likely. Some questions marks with dew points for the afternoon given some slightly more moisture surface conditions but suspect that most areas will see relative humidity drop to 30 to 40 percent. This should produce a fairly widespread high to very high fire danger.

A jet streak moves into ND on Sunday night which will allow a surface front to settle south. Not overly cold behind the front, but definitely some differences. The 10th and 90th percentiles are ranging from the mid 50s to mid 70s so a fairly wide spread. Given the latest models have this front mostly south of the area by Monday morning without coming back to the north, would side towards the middle and lower side of guidance, closer to the 25th/50th percentiles.

This jet stays in place into Tuesday which keeps the cooler air mass from advancing back to the north, so slightly cooler on Tuesday, but still above normal.

The right entrance region of this upper level jet begins to move by to the north on Tuesday night and should bring some chances for rain and snow to the area. For now not looking like anything other than minor impacts. Very low chances from the ensemble members of exceeding a tenth of an inch of liquid.

Models fairly agreeable on the next system of interest moving through Thursday into Friday. For now it looks like a bigger threat for warm temperatures and windy conditions which could lead to some elevated to critical fire weather conditions. Highs likely in the 60s Thursday which should see the highest fire weather concerns. Depending upon how far south the wave drops, could see some spotty rain and snow showers with the better chances north of I-90.

AVIATION /12Z TAFS THROUGH 12Z MONDAY/

Issued at 600 AM CDT Sun Mar 8 2026

Changing wind direction and speed will drive the change groups in this TAF period as VFR conditions will prevail across the region.

Starting the period with relatively light southwest winds. Wind will begin to increase late morning (15-16Z) as directions swing more westerly. Stronger gusts 20-30kt develop early afternoon and continue through sunset/00Z. Decoupling will drop the gusts quickly after sunset, but winds will become more variable late in the period as a front slides south into the forecast area. Ahead of this front, KSUX will see low level wind shear as a southwesterly low level jet of 40kt develops this evening.

FSD WATCHES/WARNINGS/ADVISORIES

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