textproduct: Sioux Falls

KEY MESSAGES

- Warm and predominantly dry conditions continue through most of the work week. Low (less than 25%) for showers late week near the US Highway 20 corridor.

- Warm and dry conditions and occasionally gusty afternoon winds could bring some fire weather concerns as grasses dry out.

- Widespread rain chances look to return late next weekend and early next week, but confidence in details remains low (less than 30%).

UPDATE

Issued at 312 AM CDT Tue Oct 6 2026

Taking a look across the area, clear and quiet conditions continue this morning. Similar to the previous update, still some occasional breeziness this morning mainly in areas along and east of I-29 with the nocturnal LLJ. As this feature continues to push out of our area by 7 am (12z) should see wind speeds gradually decrease through the morning. Otherwise, the forecast remains on track. Continued the trend of slightly raising temperatures and lowering dew points from the default NBM. As a result, highs will peak in the low to mid 80s for most areas. Looking aloft, a surface cold front will progress through the area by late morning bringing drier air to the area with the driest conditions across southcentral SD.

While any resulting fire weather concerns should be low to moderate, the drier air combined with the increased heat may help dry/cure the last bit of our dampened fuels especially west of Highway-281. This could play a role in future fire weather concerns. Lastly, while confidence is still low (<20%); could see the return of some lighter showers from late Thursday into Friday mainly along and south of the Missouri River Valley as a weak wave moves through the area. Any resulting accumulations would be light.

DISCUSSION

Issued at 235 PM CDT Mon Oct 5 2026

REST OF TODAY/TONIGHT: Shaping up to be another gorgeous early October day with temperatures in the 70s and lower 80s. Surface high pressure slides east today, with tightening SPG ahead of developing trough across the western Dakotas and southern Canada, were seeing gusts 25-35 mph. Some gusts around 40 mph possible in south central SD. Southerly flow and WAA continues to keep conditions warmer and drier, so raised highs and lowered dew points again for today as NBM remains too cool/moist. Warmer temperatures, dry conditions, and stronger winds could lead to some very locally elevated fire concerns this afternoon and early evening for anywhere fuels have begun to dry.

Weak mid level wave moves through this evening into tonight. Breezy conditions continue into the overnight hours, although some gusts around 30 mph remain possible near/along the Buffalo Ridge with the LLJ increasing. May see some lower clouds develop overnight ahead of a boundary but no precipitation is expected. Lows tonight remain mild, only falling into the lower and mid 50s.

TUESDAY-WEDNESDAY: Northwesterly flow aloft promotes a couple of weak waves through the northern and central Plains; however, lack of moisture keeps dry conditions in place. Surface boundary continues to slide east during the day Tuesday into the evening, with high pressure moving in for Wednesday.

Continued the trend of raising highs and lowering lows and dew points from the NBM given the continued cool and wet bias. CONSShort in addition to the 90th (higher) and 10th (lower) NBM percentiles were incorporated in to make those changes. Highs near and above 80 for most of the area Tuesday, which is about 10-15 degrees above seasonal averages. Slightly cooler Wednesday thanks to more northwesterly surface flow and CAA. Highs in the 70s and lows in the upper 40s and lower 50s.

THURSDAY-FRIDAY: Surface high slides east Thursday, with continued northwesterly flow aloft. By Thursday night, most guidance shows a surface warm front move north. Guidance is split on the track and strength of any lower and mid level waves through Friday, so confidence is lower during this time. In addition to timing and track differences, next biggest question is the depth of any moisture return. GFS/GEFS remain more bullish on the potential for measurable precipitation, with moderate to high chances (over 40%), with the ECMWF ensemble lower (40% or less). GEFS also has the highest (30% or less) probability of a tenth of an inch of rain with other ensembles even lower. Temperatures generally near to above normal.

THE WEEKEND/EARLY NEXT WEEK: Although guidance varies on the details, all deterministic models point to a shift in the pattern through next weekend and into early next week. A quick short wave moves through early in the weekend. By Sunday, ridging aloft shifts east with troughing digging into the western CONUS, bringing southwesterly flow to the region. Low pressure strengthens and moves east into the early part of the week bringing more widespread precipitation chances. Ensemble probabilities from the GFS and ECMWF show moderate to high (over 50%) chances for at least a tenth of an inch of precipitation into early Tuesday.

AVIATION /18Z TAFS THROUGH 18Z WEDNESDAY/

Issued at 1221 PM CDT Tue Oct 6 2026

VFR conditions expected through the period outside of the potential for some patchy valley fog (20% chance) early tomorrow morning. Mainly clear skies can be expected through tonight, though a few more high clouds will begin to stream in during the day Wednesday. Winds will be mainly light and out of the northwest through the period, though variable direction can be expected whenever winds go near calm this evening into tomorrow morning.

FSD WATCHES/WARNINGS/ADVISORIES

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