textproduct: Sioux Falls

KEY MESSAGES

- QUIET AND MILD: Dry conditions and above normal temperatures continue through Wednesday with highs in the 50s and 60s.

- MINIMAL RAIN MID-WEEK: The only precipitation chances in the next 7 days will occur late Tuesday night into Wednesday, but any rain will be very light and unimpactful.

- COLDER AIR AHEAD: A strong front drops temperatures significantly Thursday and Friday, though temperatures will gradually warm above normal by the end of next weekend.

DISCUSSION

Issued at 1200 PM CST Mon Nov 9 2026

THIS AFTERNOON: A weak frontal boundary has moved through the forecast area this afternoon. A warm westerly northwesterly flow behind the front continues to allow temperatures to surge into the 60s. By this evening, a light to even variable wind may develop.

TONIGHT: Outside of scattered high lvl cirrus, a rather quiet overnight period is expected. The light and variable winds that develop will promote strong radiational cooling, dropping low temperatures near the freezing mark. Some high resolution models such as the HRRR/RRFS/RAP indicate enough cooling for valley/river based fog to develop.

TUESDAY: Southwesterly surface winds will increase through the day on Tuesday as a progressive open wave begins to cross the Northern Rockies. This wave induces surface cyclogenesis across the western Dakota early in the day, increasing the SPG over the Tri-State area. With modest low-lvl warm advection in place, it's possible that temperature may warm higher than what the NBM suggests. Will trend temperatures towards the 90th percentile, indicating upper 50s to lower 60s. The relatively moisture starved trough will move through the Plains Tuesday night, pushing the surface low into Western Minnesota late in the evening and bringing strong cold advection through the Dakotas. Wind gusts through the James and Missouri River valleys have potential to reach the 35 to 45 mph range which has led me to bump winds upwards. Some questions continue on the depth of the low-lvl moisture field, which could produce a sprinkle as it moves through. The latest ensemble guidance continues to back off on the probabilities of any measurable rain (<20%).

WEDNESDAY: By Wednesday morning, the development of a large ridge over the western CONUS and a trough over the eastern CONUS will put the CWA into zone of strong cold advection. The initial surge of cold air early Wednesday won't be nearly as strong as the secondary surge that arrives Wednesday night. Thus, temperatures Wednesday afternoon may still rise into the 50s.

THURSDAY-FRIDAY: Under the influence of a modifying arctic airmass at the end of the week, temperatures will fall below normal with highs only near 40 degrees and morning lows likely to fall into the middle 20s by Friday morning. No precipitation is expected.

SATURDAY-MONDAY: Regional weather will remain very quiet through next weekend and into the early portions of next week. Mid- lvl ridging will slowly transition eastward during the weekend, allowing a slow increase in southerly to southeasterly surface winds Saturday. These winds will increase further on Sunday, introducing very low fire danger risks with gusts over 20-30 mph. Temperatures will continue to warm through the weekend, but slowly as low-lvl warm advection is not intense, and SE surface flow is less conducive to strong warming. Nevertheless, by Sunday and Monday we'll see highs back above normal into the 50s.

AVIATION /18Z TAFS THROUGH 18Z TUESDAY/

Issued at 1112 AM CST Mon Nov 9 2026

VFR conditions will continue into the overnight hours. Brief gusty winds this afternoon behind a passing front will weaken by this evening. As temperatures fall, localized patchy ground fog may be possible.

VFR conditions will continue through Tuesday.

FSD WATCHES/WARNINGS/ADVISORIES

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