textproduct: Aberdeen

KEY MESSAGES

- Above normal heat and humidity continues this afternoon. Heat index values will be in the upper 90s to 100s over much of the region. A Heat Advisory is in effect through 9 PM CDT for all counties except for Corson, Campbell, and McPherson Counties.

- The next chances for precipitation will be development along a cold front moving through the area on Sunday night. Can't entirely rule out severe weather, but confidence is low at this time.

- Temperatures look to return to normal to perhaps just below normal by mid-week next week, with highs in the 80s.

DISCUSSION

Issued at 229 PM CDT Fri Jul 17 2026

A weak cold front is completing its passage over the CWA this afternoon. While little is expected in terms of temperature reduction behind the cold front, winds will shift to become northerly to northeasterly behind the front. This shift may allow some of the Canadian/Minnesota wildfire smoke to slide into the region, particularly over northeastern South Dakota and western Minnesota. Concentrations are not expected to be particularly high (only around 8-12 um/m3 at the surface), but would represent an increase from the current state and may have an impact on temperatures by nudging things down a degree or two tomorrow. Overall expect minimal health impacts from the smoke, as the Air Quality Index over the region will remain at "Good" to "Moderate" levels.

Above normal heat continues this afternoon, with a Heat Advisory in effect through 9 PM CDT tonight for most of the area. The broad- upper-level ridge in place will begin to flatten out over the weekend. This combined with the northerly winds shutting off the warm air advection will help decrease temperatures slightly Saturday. Highs will briefly fall into the upper 80s to mid 90s (increasing from east to west) Saturday afternoon. A high pressure center passing to the north will flip winds back to southerly by Sunday, returning the area to a warm air advection regime and bringing highs back up into the upper 90s (potentially reaching triple digits over central and north central South Dakota).

Another cold front moves through the area Sunday, with this one having the potential to develop some scattered storms. There is still some uncertainty on timing, but the best chances for development appear to be Sunday night over northeastern South Dakota and western Minnesota. Can't quite rule out a potential severe threat, although the best environment will be further north into North Dakota and Minnesota. The main severe threat, should storms develop, would be hail. Supporting this hail threat would be MUCPAE of 1500-2500 J/kg, ~40 knots of shear, and mid-level lapse rates of 7-8 C/km.

Into next week, an upper-level trough deepens over the eastern CONUS, subsequently enhancing the ridge over the western CONUS. This will put the northern plains into the transition zone between the two features, bringing cold air advection aloft to the area. This setup helps to finally cool the area down, and highs by mid-week next week will be near-normal to perhaps slightly below normal. In terms of precipitation chances, little of note in the extended at this time. Latest NBM runs call for some rain chances over parts of central South Dakota mid-week, but the severe environment looks less than impressive at this point, and would currently not expect much out of anything that may develop.

AVIATION /18Z TAFS THROUGH 18Z SATURDAY/

Issued at 1215 PM CDT Fri Jul 17 2026

Terminals KABR,KATY,KPIR,KMBG

Clear skies over central and eastern South Dakota this afternoon, but skies are slightly chaotic in terms of cloud cover over parts of northern South Dakota. While clouds will likely dissipate over the next couple of hours and VFR conditions are generally expected through the TAF period regardless, there may be points at which KABR and/or KMBG could drop to MVFR ceilings briefly. Otherwise, a weak cold front finishes its passage across the forecast area this afternoon, shifting winds to become northerly for the rest of this afternoon and evening. A high pressure center passing to the north will veer winds slightly, carrying a more easterly component for the second half of the TAF period.

ABR WATCHES/WARNINGS/ADVISORIES

SD...Heat Advisory until 9 PM CDT /8 PM MDT/ this evening for SDZ006>011-015>023-033>037-045-048-051. MN...Heat Advisory until 9 PM CDT this evening for MNZ039-046.