textproduct: Sioux Falls

KEY MESSAGES

- Low stratus will continue into Saturday. Peaks of sunshine are possible later Friday afternoon mainly near and west of I-29, but will do little to impact high temperatures.

- Patchy fog is possible through early Friday morning mainly in south-central South Dakota. There is a low to medium chance (20-40%) of visibilities dropping below one mile in these locations.

- Overnight lows will be slightly warmer than previously forecasted due to cloud cover. Most will see lows range between 30-35 deg F, though a few upper 20s will be possible mainly in south-central South Dakota.

- An extended period of dry weather is likely through most of next week as temperatures rise back above normal.

UPDATE

Issued at 854 PM CST Thu Nov 5 2026

Stratus continues to blanket the area this evening, though it has eroded a bit in south-central South Dakota. With that, these areas will likely be some of the coldest spots tonight, with lows around 30 degrees, locally into the upper 20s. This is also where we have the best chance of fog developing over the next few hours as temperatures here cool faster to the dew point. There is a low to medium chance (20-40%) of visibilities dropping below 1 mile through daybreak in these areas, so be sure to check conditions before heading out the door. Should note that even if air temperatures are below freezing when there is fog, road temperatures will be warm enough to prevent any slick spots from developing. But if temperatures can drop enough, and fog can stay thick enough for along enough time, then perhaps some very light icing will be possible on tree branches. But I would even put the chance of this occurring at less than 5% and as such, you'll have to wait a bit longer if you're wanting a wintry scene.

Elsewhere, stratus lingers and thus temperatures will be slow to cool off and lows outside of south-central South Dakota will range from the low to middle 30s. A few spits of drizzle will remain a possibility tonight in this stratus, but most of us will be dry. Just like for fog, any drizzle in below freezing temperatures will not create any slick roads tonight. Not even on tree branches as any drizzle is expected to remain very light. Stratus looks to linger into much of the day on Friday and keep things chilly; however, it won't feel as bitter outside as it was today as winds will be light Friday. Most locations will stay in the lower to middle 40s for highs, though stratus may be able to scatter out west of the James River prior to sunset allowing for these locations to reach the upper 40s to potentially around 50. However, a weak wave moving towards the area will send some mid level clouds, so even if the stratus scatters, full on sunshine is not expected. Currently think stratus will stick around throughout the day east of the James River, though perhaps near and west of I-29 you'll be able to see the sun in the distant horizon right before it sets.

DISCUSSION

Issued at 158 PM CST Thu Nov 5 2026

Low stratus continues to flow in from the north, obscuring skies. While there is considerable dry and subsiding air aloft, a shallow layer of moisture exists between 925-850 mb. Soundings indicate this layer of moisture will persist through tonight and much of Friday. Weak instability in this layer may also allow for some light sprinkles to drizzle. No accumulation is expected. Stratus will limit the area previously expected to see a hard freeze tonight (28 deg F or less). After coordinating with neighbors, have boosted overnight lows with a blend of NBM and RAP13. Overnight lows now range from 29 to 33, warmest over northwest Iowa. Should any area dip into 28 degrees or less it will most likely occur along and north of Highway 14 in eastern South Dakota. Breezy northerly winds will continue to decrease the remainder of this afternoon, becoming light and variable over night. Areas of low stratus/fog may briefly reduce visibility to 1 mile or less. Confidence in fog formation is low with the REFS indicating a less than 25% probability. Any fog should burn off by mid-Friday morning.

By Friday afternoon weak upper ridging and a surface high pressure push in from the west. This will finally begin to break up the clouds late Friday afternoon as slightly stronger southerly winds work into the low levels. While we will likely see peaks of sunshine, it will probably not be enough to boost our high temperatures. Most areas will see low to mid 40s, while south central South Dakota may just squeak into the low 50s. By Friday evening the surface high will be centered over Iowa and weak low level moisture return will flow in from the south. At the same time a shortwave and WAA will pass through the region. With little instability or shear to speak of the most likely result is another round of low stratus. This will once again work to limit overnight lows to the low to mid 30s. Light and variable winds with surface conditions near saturation may allow for the stratus to lower and/or fog to develop. As flow aloft becomes northwesterly clouds and fog will scour out by late Saturday morning.

Dry, mostly sunny skies, light southerly winds, and WAA will follow for the rest of Saturday with highs climbing into the mid 50s to low 60s over south central South Dakota. Similar conditions for Sunday and Monday will see highs climb into upper 50s to mid 60s both days. Monday afternoon a dry upper wave and cold front will pass through the region. Winds will become northerly and temperatures will cool into the 50s for Tuesday. Similar conditions continue into the latter half of next week.

AVIATION /06Z TAFS THROUGH 06Z SATURDAY/

Issued at 1114 PM CST Thu Nov 5 2026

MVFR to locally IFR stratus continues to blanket the area this morning, and this will continue to be the case heading into the daytime today. This stratus will likely scatter out from west to east starting this afternoon, reaching the I-29 corridor after sunset and marking the return of VFR conditions to end the period.

Winds will turn more south-southeasterly heading into the day on Friday but remain on the lighter side of things through the period around 4-9 kts.

FSD WATCHES/WARNINGS/ADVISORIES

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