textproduct: Sioux Falls

KEY MESSAGES

- Breezy southerly wind gusts 25 to 35 mph into the evening. Gusts as high as 40 mph in south central South Dakota. Wind gusts 20 to 30 mph may continue tonight in higher elevations.

- 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%).

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 TUESDAY/

Issued at 1226 PM CDT Mon Oct 5 2026

VFR conditions through the period; however, some guidance hints at some lower VFR to upper level MVFR clouds near/east of I-29 late tonight into early Tuesday morning. That said, not expecting more than FEW/SCT coverage at this time.

Main concern through the period remains winds. Southerly winds gust this afternoon and evening of 20 to 30 knots, up to 35 knots in south central SD. Winds may still gust around 25 knots overnight, stronger across the higher elevations of the Buffalo Ridge. LLJ strengthens overnight mainly along/east of the James River which brings LLWS to areas near I-29 and east where the LLJ is strongest. Winds begin to shift to the west/northwest through Tuesday morning and early afternoon.

FSD WATCHES/WARNINGS/ADVISORIES

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