textproduct: Sioux Falls

KEY MESSAGES

- Low stratus will continue into Saturday. Peaks of sunshine are possible Friday afternoon, but will do little to impact high temperatures.

- Low confidence (<25% probability) of low stratus/fog impacting visibility overnight. Low areas and river valleys may briefly see a reduction in visibility to less than 1 mile.

- Overnight lows will be slightly warmer than previously forecasted, limiting the area likely to see a hard freeze to along and north of Highway 14 in eastern South Dakota. Most will see lows range between 29-30 deg F.

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

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 /18Z TAFS THROUGH 18Z FRIDAY/

Issued at 1140 AM CST Thu Nov 5 2026

A mix of MVFR down to IFR will prevail for most of the period. This is due to a layer of low stratus between 925 - 850 mb that continues to flow in from the north. Weak winds in this layer will allow stratus to linger into Friday late morning. As an upper ridge and surface high push in from the west stratus will finally begin to break up Friday afternoon and continue to dissipate through the end of the period, with ceilings returning to VFR near the end of the period.

Breezy northerly winds gusting 20-25 kts will decrease through the remainder of this afternoon, becoming light and variable overnight. Some patchy fog is possible, however confidence is low. The REFS indicates less than a 25% probability of visibility less than 1 mile. Area most likely to see some fog development will be along river valleys and low areas. Any fog should dissipate by mid-Friday morning.

FSD WATCHES/WARNINGS/ADVISORIES

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