textproduct: Sioux Falls

KEY MESSAGES

- Showers and isolated thunderstorms move into the US Highway 14 corridor this morning. Severe storms not anticipated but may see some gusts around 45 mph.

- Isolated to scattered (30% chance or less) thunderstorms return to the area this afternoon through the evening. An isolated stronger storm may produce hail to quarter size and wind gusts to 60 mph; greatest risk across southeastern South Dakota into southwestern Minnesota and far northwestern Iowa.

- Temperatures through the upcoming week will trend warmer, with widespread highs in the 90s to near 100 through much of next week. A day or two may feature Heat Advisory conditions. The cumulative nature of the heat could lead to heat illness.

UPDATE

Issued at 302 AM CDT Fri Jul 10 2026

Some very patchy fog is developing along the US Hwy 71 corridor where skies are clear and winds are light. Visibility may drop below 2 miles at times through this morning. Further north, watching a cluster of weakening thunderstorms across northeastern SD which should move into the US Hwy 14 corridor toward daybreak. The outflow is significantly ahead of the storms and already firing off some additional showers and isolated storms along US Hwy 14. Gusts are tapering down, but have seen gusts as high as 50 mph with the outflow earlier this morning.

Rest of today, mid/upper wave should skirt just south of the area through early afternoon. This could fire off a couple showers and maybe isolated storms in northern NE and the part of the southern MO Valley this afternoon, with soundings not showing much in the way of a cap. Meanwhile, we'll be keeping an eye on where the remnants of this morning's convection end up as well as any associated boundaries, which may help trigger some isolated to scattered showers and storms this afternoon/evening across the area. Area of development looks to be across mainly southeastern SD into southwestern MN and far northwestern IA where another very subtle vort lobe moves through into the evening. Although shear is meager at best, there's modest instability and an eroding cap this afternoon into the evening. Mid level lapse rates around 6.5 deg C/km could support quarter sized hail, and with high DCAPE, isolated 60 mph wind gusts are possible.

Confidence remains high in warming temperatures through the weekend into next week. Models have maintained recent trends of lighter winds and mixing down drier air keeping heat index values below critical thresholds. However, with overnight lows in the upper 60s and mid 70s and the cumulative impacts of numerous days of temperatures above average, HeatRisk will remain in the Minor to Major categories through much of the week, with pockets of Extreme. If you have outdoor plans or if you are more susceptible/vulnerable to the heat, be prepared for heat impacts and take extra precautions.

DISCUSSION

Issued at 143 PM CDT Thu Jul 9 2026

THIS AFTERNOON: Quiet conditions are likely this afternoon as winds remain light and variable.

TONIGHT: Scattered convection that forms over the western High Plains will begin to roll eastward through the evening hours as a shortwave moves into the region. The majority of instability remains bottled up over the West River areas through the evening, and as convection slides eastward it's likely to diminish quickly by time it reaches the CWA. A few gusty winds with decaying showers could still be possible into south central SD. The remnant area of vorticity may drift into northern Nebraska, and could keep a low risk for convection through daybreak in the MO River valley.

FRIDAY: A secondary area of convection may form over central ND late tonight, and slowly drift into northeastern SD by mid-morning Friday. A potential MCV could linger into Friday afternoon over the SD portions of the Buffalo Ridge, and with that area on the edge of the low-lvl EML, can't rule out isolated to scattered convection forming after 4-5pm. From a parameter perspective, MLCAPE values remain near 2000 J/KG, but effective shear is very weak, suggesting only pulse strong storms with wind and brief hail could be possible into SW Minnesota during the evening. As instability pulls northward in the evening the severe weather risk should diminish quickly. Elsewhere, a breezy southwest wind will push highs into the upper 80s to lower 90s.

THIS WEEKEND: Mid-lvl heights begin to rise quickly as we head into the weekend, which will begin a stead upwards rise in temperatures. One thing to note in recent guidance is that surface winds Saturday and Sunday remain more from the southeast and rather light, which could hold down the extreme climb in highs suggested a few days ago. We'll also see a bit more mix down of dry air as soundings have also trended a bit drier, this will allow afternoon dew points to fall and keep heat index values below critical limits.

MONDAY-THURSDAY: A dry and hot week is expected in the region as a 600+ DM 500 mb ridge centers itself over the CWA. The placement of the ridge prevent any storm development, but allow temperatures to climb through the 90s most days. Confidence is high that we'll see temperatures in the middle to upper 90s in most locations, with some areas reaching 100 along and west of the James River valley. The EC ensemble supports this idea with 60%+ probabilities along the James River valley Monday-Thursday. With afternoon dew points mixing down at least into the upper 50s to lower 60s, this should prevent widespread heat index readings over 100 degrees. While the day to day numbers may not be extreme, the cumulative effect of the heat could lead to health related strain by mid-late week.

AVIATION /06Z TAFS THROUGH 06Z SATURDAY/

Issued at 1216 AM CDT Fri Jul 10 2026

VFR conditions are expected for the period. Mid to high level clouds continue to flow in from storms to the southwest in central Nebraska. These are not expected to impact flight operations. Winds will be light and variable. Areas of northwest Iowa may see some patchy dense fog in the few hours preceding sunrise. Fog should burn off by mid morning.

Low chances (<25%) for rain and possibly weak thunderstorms beginning Friday morning around 6 am and continuing through around 10 am. A weakly unstable environment may support thunder and a few wind gusts to 45 mph, but severe weather is not anticipated. These are expected to remain in east central South Dakota and southwest Minnesota.

A second round of showers and storms are possible in the afternoon from around 4 pm until roughly 10 pm. Better instability but weakly sheared means these storms will likely be pulsy in nature. Some may briefly produce hail to the size of a quarter and wind gusts to 60 mph. This round is expected to be located roughly along and east of I-29 into southwest Minnesota and northwest Iowa.

FSD WATCHES/WARNINGS/ADVISORIES

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