textproduct: Sioux Falls

KEY MESSAGES

- An extended period of warm and dry conditions continues for much of the work week.

- Warm temperatures and occasionally gusty afternoon winds could bring some fire weather concerns as fine fuels start drying out.

- Rain chances may return next weekend, but confidence in details is low (less than 20%).

DISCUSSION

Issued at 228 PM CDT Sun Oct 4 2026

REST OF TODAY/TONIGHT: High pressure continues this afternoon and evening leading to an absolutely gorgeous early October day. Skies have remained mostly clear with a few high clouds along the MO Valley. Light and variable winds with temperatures warming into the 60s and lower 70s. Continued the trend of the previous shifts to raise temperatures and lower dew points from the NBM given recent cool/wet bias.

High pressure continues to slide east this evening and overnight, which allows southerly flow to return the area, especially west of I- 29. Slightly adjusted temperatures as we may stay a bit warmer in this area. Winds increase overnight as the SPG compresses between departing high pressure and the incoming front Monday. Lows tonight fall into the 40s and 50s, cooler in the east with clear skies and light winds while warmer lows expected in the west with the quicker return of southerly flow.

MONDAY: Based on the recent bias in the blend, raised temperatures and lowered dew points a touch for the afternoon/evening hours. Some locations across south central SD should warm near 80 degrees, especially as southerly flow and WAA increase. Winds strengthen as well, with gusts reaching 40 mph in south central SD with 25-35 mph gusts common elsewhere. Will have to watch for stronger gusts in the higher elevations overnight into Tuesday morning with the LLJ. Highs in the 70s for most (outside of south central SD). Lows Monday night remain in the 50s.

TUESDAY-WEDNESDAY: Mid level wave and surface trough slide through Tuesday morning. Expect dry conditions with a lack of appreciable moisture. Northwesterly flow aloft and Tuesday at the surface may keep temperatures a couple of degrees cooler on Tuesday, but still above average. Stronger push of CAA with another mid level wave through the northwesterly flow cools temperatures slightly again on Wednesday. Highs in the 70s to near 80 (Tuesday) and 70s (Wednesday) with lows in the 40s and 50s.

THURSDAY-FRIDAY: Northwesterly flow remains over the central US as ridging slowly breaks down over the western US by the end of the week. A couple of waves move through during this time, bringing some low end precipitation chances. Deterministic and ensemble guidance has backed off a bit on the potential for precipitation Thursday with less certainty in the pattern and location of any elevated fronts. Given the uncertainty, left the NBM for now.

As for Friday, guidance is in a bit better agreement with a surface warm front lifting north and a more defined 700 mb wave as flow aloft shifts westerly. Lower level moisture is better Thursday night into Friday than Thursday morning/afternoon with more southeasterly flow. However, ensemble probability for more than 0.01" of rain in a 24 hour period remains low, at 25% or less. Confidence is low given questions about forcing. Quite a bit of uncertainty in temperatures as well, with a 10 or more degree spread between the deterministic ECMWF (warmer) and the GFS (cooler). Breezy conditions return Friday.

NEXT WEEKEND: Pattern shift continues into next weekend with split mid and upper level flow. Expect warmer temperatures with southwesterly flow. A breezy to gusty weekend is expected, with the strongest winds on Saturday. Guidance is quite varied on when/where any precipitation chances would be, with the GFS quickest with QPF. Ensemble probabilities of 24 hour precipitation of 0.10" are low (as high as 30%) into early Monday morning.

AVIATION /18Z TAFS THROUGH 18Z MONDAY/

Issued at 1216 PM CDT Sun Oct 4 2026

VFR conditions through the period, with high clouds prevailing. Some soundings indicate that there may be some clouds around 8kft near/east of I-29 overnight, but given most of the guidance keeping this layer dry, did not include. Main focus for this period will be light and variable winds into tonight shifting to southerly by tomorrow afternoon. Expect the wind shift to occur from west to east into Monday morning. Gusts of 20 to 30 knots expected by the end of the forecast period.

FSD WATCHES/WARNINGS/ADVISORIES

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