textproduct: Sioux Falls

KEY MESSAGES

- A wintry mix impacts areas south of I-90 in South Dakota and into northeast Nebraska Friday, with lower chances in northwest Iowa later today. Light snow/sleet will be most likely, but south central South Dakota (Gregory/Charles Mix/Bon Homme counties) could see a light glaze of light freezing rain.

- Have issued a Winter Weather Advisory for areas where ice accretion is most likely today and into this evening - the western Missouri River Valley.

- Stratus and seasonably cool temperatures persist today, then temperatures trend above normal heading into next week.

- Next week could bring a couple of light precipitation chances to parts of the region Tuesday and/or Thursday, but at this time the potential for significant precipitation is low (<20%). More widespread chances may return to end next week.

DISCUSSION

Issued at 320 AM CST Fri Jan 2 2026

THROUGH TONIGHT: Stratus has kept temperatures in the upper teens and 20s. Have seen some fog, including patchy dense fog along and west of the MO River in south central SD. Further east, have seen some very patchy flurries in the lowest stratus deck.

As we head through the day today, a mid level short wave passes through and south of the MO River Valley. This wave is generally weakly forced, but should be enough moisture for some light and mixed precipitation over the area through the day and into this evening, focused toward the MO River Valley, but stretching up toward the I-90 corridor. A few questions remain regarding precipitation type and accumulations due to a dry layer aloft, slower saturation in the DGZ, saturated low levels, and the timing of the warm nose (WAA) aloft. However, think that we'll see a brief period of an hour or two where the western MO River Valley will see some light freezing rain before switching to sleet and snow. This transition should happen fairly quickly - especially as you head further east. Amounts remain light, with less than a 15% chance for more than an inch of snow. Guidance shows the highest probability of ice accretion of 0.01" stretching from far southwestern Gregory county southeast into eastern NE. Did issue a Winter Weather Advisory for Gregory, Charles Mix, and Bon Homme counties where highest ice and sleet accumulations are anticipated. These locations will see a light glaze of ice to a couple of hundredths. The Winter Weather Advisory may need to be expanded if saturation/temperature cooling occurs more slowly and areas east see more freezing rain/sleet than anticipated.

This system pushes out of the area tonight. A very weak wave moves through the eastern portions of the area tonight, which could lead to light snow/flurries east of I-29. Limited pops though to approximately 20% or less given questions about available moisture.

Not much change in temperatures for most of the area today and even into tonight as stratus lingers. Highs in the teens and 20s with lows tonight a few degrees cooler.

SATURDAY-TUESDAY: Stratus lingers into the first part of the weekend with saturate low levels and weak flow. Guidance varies on how quickly stratus moves east, which will impact temperatures. Have kept things on the colder side for southwestern MN, with moderating temps across south central SD. The weekend and to start next week sees dry conditions, with temperatures above normal temperatures returning. Ridging slides east through the second half of the weekend. By Monday, flow becomes more westerly, with a stronger wave progged to move through the Plains Monday night into Tuesday. Given disagreements in timing/location of the wave, left NBM as is for now with some low end pops across southwestern MN.

WEDNESDAY ONWARD: South to southwesterly flow aloft brings warmer temperatures back to the region mid week, with slightly cooler temperatures to end next week. Guidance is still quite variable with the details, but a couple of waves are expected to move through the area. The first Wednesday night south of the area could bring light precip to portions of the area. Will be keeping an eye on the potential for a deepening trough/strengthening upper level northern jet late Thursday into Friday next week which could bring more widespread precipitation to the northern and central Plains into the upper Midwest.

AVIATION /06Z TAFS THROUGH 06Z SATURDAY/

Issued at 1048 PM CST Thu Jan 1 2026

Low level stratus persists across the entire area late this evening. Visibilities remain vastly VFR beneath the stratus but a few locations across the western portion of Gregory county are reporting patchy fog with visibilities down to a mile or less. Thankfully, the fog will stay in Gregory county and will not expand to the east. Ceilings in the stratus remain largely IFR with pockets of MVFR and LIFR. The low level stratus and patchy fog will persist through the night along with light winds.

Precipitation remains on track to return to the area, beginning across south central South Dakota tomorrow morning. Precipitation will be mixed but will transition to mainly snow by the afternoon timeframe as it slides eastwards. Should see the extent of precip remain south of I-90 through the rest of Friday afternoon. Ceilings will remain IFR/LIFR during this period of time with visibilities only dropping in falling precipitation. Should see the snow reach KSUX during the afternoon with maybe some very light snow to flurries reaching up to KFSD. Snow chances looks to wind down Friday evening though there is some uncertainty in when the precip will end across the area.

FSD WATCHES/WARNINGS/ADVISORIES

SD...Winter Weather Advisory until 6 PM CST this evening for SDZ050- 063-068. MN...None. IA...None. NE...None.