textproduct: Sioux Falls

KEY MESSAGES

- Isolated strong to severe thunderstorms can't be ruled out this evening, especially east of I-29. 60 mph wind gusts will be the threat, though widespread strong to severe storms are not expected.

- Winds increase tonight into tomorrow morning, gusting up to 50 mph at times especially north of I-90 and into portions of northwest Iowa. This will also lead to fire weather concerns especially along and south of I-90 where relative humidity values will be lowest.

- The potential for light accumulating snow returns Thursday into Thursday night. The best chance for at least an inch of snow (40-60%) is south of I-90 at this time. A narrow band of 2-4+" inches may set up over parts of our area, though uncertainty in the placement of this heavier band remains high.

DISCUSSION

Issued at 240 PM CST Tue Feb 17 2026

One last very warm February day out there, with temperatures having climbed mainly into the 60s. It's been a breezy day too, and these winds will diminish this evening, at least for a few hours. A cold front will be moving through the area this evening as well and will help provide some lift for showers to develop. These showers will actually some elevated instability to work with, and thus a few thunderstorms cannot be ruled out. Can't entirely rule out an isolated severe storm as there will be ample dry air beneath these elevated storms. This would mean gusts potentially as high as 60 mph, but widespread strong to severe storms are not expected. Synoptic winds will increase through tonight as strong cold air advection pushes into the area behind the cold front, with gusts up to 50 mph expected. This will be the case especially for areas north of I-90 where the Wind Advisory has been expanded to include the rest of southwest Minnesota north of I-90. These stronger winds will spread into northwest Iowa heading into tomorrow morning, but the current thinking is the chances for these stronger wind gusts in excess of 45 mph will only last an hour or two, so did not expand the advisory at this time and will be captured by the Fire Weather Watch. More on that in the fire weather discussion later on.

Some wrap-around precipitation may impact mainly the Highway-14 corridor late tonight into tomorrow morning. This will likely start as light to very rain, turn to light to very light snow, and then back to rain before exiting. Not expecting any snow with this to accumulate, but there could be very brief reductions in visibility in any light snow due to the stronger winds that will be in place during the morning commute tomorrow. Temperatures turn cooler heading into the day tomorrow behind the aforementioned cold front, with highs mainly in the 40s and 50s. Of course, this is still above normal, but it only gets colder from here.

Heading into Wednesday night and Thursday, a surface low will move across the central Plains, with most guidance then pulling the system northeastward to the Great Lakes by Thursday night/Friday. 17.12z guidance has continued to show the southerly trend of the low through the central Plains as shown in the 17.06z guidance, and this has lead to the latest NBM pulling the 2+ inch snow amounts farther south and east closer to a Sioux City, IA to Jackson, MN line. Looking at the 17.12z ensembles, there appears to be less of a noticeable southerly trend as some of the deterministic models, so it's entirely possible the next suite of deterministic guidance starts to pull the snow farther north again. All that to say, still a lot of uncertainty in exact amounts, but even with light snow, reductions in visibility will be possible due to breezy conditions. As of now and based on the current forecasted track of the system, most spots south of I-90 look to see a moderate (40-60%) chance of snow of at least one inch of snow. There may be a narrow stripe of 2- 4+" of snow depending on where the heaviest band of snow moves through. This would be favoring areas closer to the Highway-20 corridor at this time, but again uncertainty remains high on where this band sets up, so be sure to keep up to date with the latest forecast. Chances of greater than 4 inches of snow remains low (<20%), but can't be completely ruled out.

For timing, look for some light snow to start to move into the Missouri River Valley by Thursday morning, with snow chances gradually lifting northeastward through the afternoon and evening. Snow should exit from northwest Iowa and adjacent southwest Minnesota Thursday night. Not much time to look into the long-range forecast, but temperatures do look to be colder heading into the weekend. Highs return mainly to the 20s and 30s with lows down in to single digits, though temperatures could trend colder or warmer depending on how much snow falls.

AVIATION /18Z TAFS THROUGH 18Z WEDNESDAY/

Issued at 1202 PM CST Tue Feb 17 2026

Winds today are out of the southeast and gusting 23-33kts with the highest gusts between the James River Valley and I-29. This afternoon into the evening, a cold front will move northeast through the region. Winds behind the front will turn westerly this evening and increase rapidly. Gusts of 30-40 kts are expected after midnight tonight through mid-day Wednesday. There is some indication of patchy LLWS as the frontal passage occurs, but confidence of shear at any one TAF site was too low to include at this time.

VFR ceilings are expected for the first half of this period. As the previously mentioned cold front moves through isolated to scattered light rain showers are expected. There may even be a few rumbles of thunder with some stronger showers. Severe weather is not expected, but some storms may produce wind gusts of 40-45 kts. Showers are expected to begin around 00Z and should be clear of the region around 06Z. Under showers low VFR ceilings are possible.

FIRE WEATHER

Issued at 240 PM CST Tue Feb 17 2026

Winds will be stronger heading into the day on Wednesday, gusting in excess of 40 mph at times especially during the morning hours and especially north of Highway-18. Relative humidity values will be dropping to critical levels in the afternoon, especially along and south of I-90. So even though winds will be slowly diminishing through the afternoon hours, there is enough overlap especially along and south of I-90 to warrant issuing a Fire Weather Watch 11 am to 6 pm tomorrow. Wind direction should primarily be out of the west through the day tomorrow. Fire weather conditions will diminish on Thursday and through the weekend as snow chances and colder temperatures make a return.

FSD WATCHES/WARNINGS/ADVISORIES

SD...Fire Weather Watch Wednesday morning for SDZ050-057>071. Wind Advisory from midnight tonight to noon CST Wednesday for SDZ038>040-052>061. MN...Fire Weather Watch Wednesday morning for MNZ089-090-098. Wind Advisory from midnight tonight to noon CST Wednesday for MNZ071-072-080-081-097. IA...Fire Weather Watch Wednesday morning for IAZ001>003-012>014- 020>022-031-032. NE...Fire Weather Watch Wednesday morning for NEZ013-014.