textproduct: Sioux Falls

KEY MESSAGES

- Mild temperatures will continue through much of the week ahead, as much as 15-30 degrees above normal in some areas west of I-29 today and region-wide on Monday. A few record highs may be tied or broken on Monday.

- Low afternoon humidity levels and breezy winds in the warmest areas south of I-90 Monday may again result in elevated fire danger.

- Quiet weather will prevail through early Wednesday, with a chance of light rain/snow later Wednesday-Thursday.

DISCUSSION

Issued at 305 AM CST Sun Feb 8 2026

TODAY-MONDAY: Near-term concern this morning will be a potential for stratus and/or fog to work southward in areas near to west of the James River Valley. HREF seems to have a decent handle on the current low stratus approaching Aberdeen, and indicates this will continue to expand southward through Huron-Mitchell after sunrise before thinning/retreating north again around midday. Fog potential is less certain, but is slightly favored west of the stratus for a few hours either side of sunrise. If stratus expands as anticipated, this could hold temperatures a little cooler through the James River Valley this morning, but sunshine and a light westerly low level flow this afternoon would still support highs near 50 in areas from Huron/Mitchell, southeast through Sioux Falls and Sioux City. Cooler but still mild highs in the 40s are expected east of this line, with a moderate-high (60-90%) probability of highs topping 60F in south-central South Dakota, including Gregory and portions of Charles Mix counties.

The wedge of warm air expands east on Monday ahead of a broad mid level wave and associated cool front. Timing of the front and increasing mid-high level clouds ahead of the wave could have an impact on highs Monday, especially across our northern areas. While the latest NBM continues to show a high (>80%) probability of highs topping 50F in areas along/south of I-90 on Monday, this probability drops to less than 50% through the Highway 14 corridor. In contrast, our southern areas have the greatest chance to see anomalous warmth and potentially a few new record highs, with a moderate-high (60-80%) probability of exceeding 60F from around Pickstown/Fort Randall Dam through the Sioux City area. The warmer temperatures in these areas will also lead to relative humidity levels as low as 25-40% in the afternoon, with a modest westerly breeze gusting 20-25 mph resulting in elevated fire danger for locations near/south of I-90.

TUESDAY-THURSDAY: A cooler but still above normal day expected for Tuesday with weak ridging keeping precipitation chances at bay. Highs should generally be in the 40s. Models are showing some discrepancies in the timing/track of a mid-week wave which will break down the ridge. At first glance it appears the broad low-moderate (30-50%) chances for light precipitation Wednesday night and Thursday are largely driven by higher probabilities in the EC ensemble. However, cluster analysis reveals support for the EC chances in just under 50% of GEFS members and better than 70% of Canadian ensemble members. The clusters which depict the higher precipitation chances are also on the cooler side of the guidance spectrum with regard to temperatures, so NBM highs for Thursday may be on the high side if precipitation does occur, but it still looks like mainly a rain/snow system with little indication that freezing rain/sleet will be a concern. In any case, precipitation looks to remain on the light side with less than 50% probability that (liquid) precipitation totals in this 24 hour period will exceed 0.10".

FRIDAY-SATURDAY: Although the jet stream does transition toward the central Plains late in the week, not seeing any signs of significantly cooler air pushing into the northern Plains, with 850mb ensemble mean temperatures remaining in the upper 1/3 to 1/2 of climatology for mid-February. While confidence is rather high that temperatures will remain above normal, confidence in precipitation chances by Friday-Saturday is low, with models showing little agreement in handling of split flow.

AVIATION /06Z TAFS THROUGH 06Z MONDAY/

Issued at 1038 PM CST Sat Feb 7 2026

VFR conditions begin the TAF period along with light to marginally breezy winds. Low level stratus is currently sitting across a large part of North Dakota late this evening and looks to push into locations west of the James River late tonight into tomorrow morning, including KHON. Have included MVFR ceilings in KHONs TAF but there remains the potential for IFR ceilings and potentially some patchy fog as well. Any low level stratus that gets into the area will retreat during the second half of the morning and early afternoon hours, leaving mainly clear skies along with light winds for the rest of the TAF period.

FSD WATCHES/WARNINGS/ADVISORIES

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