textproduct: Aberdeen

KEY MESSAGES

- Humidity below 25 percent and gusts of 25 to 35 miles per hour combine to create elevated fire weather concerns for the remainder of the afternoon. A Red Flag Warning is in effect until 8 PM CDT for counties including Brown and Spink and east.

- Slight cooldown expected for the weekend, with highs in the upper 50s to 60s both days (roughly 5 to 10 degrees below normal). Frost development and freezing temperatures will be possible overnight both Saturday night and Sunday night. Temperatures will warm back up next week, with highs in the 70s to low 80s, roughly 10 to 15 degrees above normal.

DISCUSSION

Issued at 217 PM CDT Fri May 8 2026

Dry and windy conditions are occurring this afternoon, with widespread observations of humidity below 25 percent. When combined with the winds of 30+ miles per hour this afternoon, areas from Brown and Spink counties and east are seeing Red Flag Warning conditions. This is expected to continue for the remainder of this afternoon before winds die down and humidity begins to recover in the evening. The Red Flag Warning for that area will continue through 8 PM CDT. As of ~19Z, humidity observations west of Brown and Spink counties has remained above 20 percent, the Red Flag Warning criteria for that area. Keeping a close eye on observations for the remainder of the afternoon, but at the moment not anticipating issuing an additional warning this afternoon.

Hi-res model guidance shows a fair degree of agreement on chances for some rain over northeastern South Dakota and western Minnesota tonight developing along a weak cold front dropping south into the area. Generally expecting accumulation to remain below a tenth of an inch, although some CAMs show a swath of up to two tenths of an inch that may impact part of the forecast area. Rain is expected to be done before sunrise Saturday morning.

While not strong, the aforementioned cold front will drop temperatures slightly for the weekend. Highs in the upper 50s to 60s expected both Saturday and Sunday, roughly 5 to 10 degrees below normal. This cooldown will be enough to support frost and freeze potential overnight both Saturday night and Sunday night (and corresponding headlines may now be sent out, as the frost/freeze program for the year has just begun). At the moment, overnight lows are forecast to be in the 33 to 36 degree range (widespread Saturday night, mainly the James River Valley and east Sunday night), so not quite freezing, but cold enough to support a few hours of frost development. Some localized areas may get down to freezing for a few hours as well both nights.

An upper-level ridge will move over the northern plains early next week. This will allow warmer air to move overhead, and 850mb temperatures increase to the low double digits Celsius (roughly the 75th percentile for this time of year). As a result, expecting highs in the 70s to low 80s next week, roughly 10 to 15 degrees above mid- May normals.

A shortwave embedded into the upper-level ridge will move overhead, bringing a jet streak along with it. The latest model runs have become much more consistent with the location of the jet streak, so confidence has increased on at least part of the Aberdeen forecast area seeing some shower development due to the divergence aloft. Thunderstorm development does appear possible given model soundings and a plume of MUCAPE extending up into the region. Latest guidance has trended timing of the jet streak to be after midnight, meaning that with the diurnal surface inversion in place any thunderstorms will likely be elevated. Therefore, while a severe storm can't quite be ruled out, wind will have a difficult time reaching the surface, and confidence is low on enough instability aloft to create the necessary updraft for severe hail (although severe hail is a better bet than severe wind if you had to pick between the two). All this to say that thunderstorms that develop will likely be sub-severe with this system.

AVIATION /18Z TAFS THROUGH 18Z SATURDAY/

Issued at 1221 PM CDT Fri May 8 2026

Terminals KABR,KATY,KPIR,KMBG

VFR conditions are expected through the TAF period. Mostly clear skies expected this afternoon, with the exception of some scattered mid clouds that may produce virga at times. Expect additional high clouds to move overhead overnight tonight. Main aviation concern is strong northwesterly wind gusts through this afternoon, up to 25 to 30 knots. Winds will die down this evening, with direction shifting to the southwest over central South Dakota. Winds turn back north early Saturday morning, increasing to 20 to 25 knots by the afternoon.

ABR WATCHES/WARNINGS/ADVISORIES

SD...Red Flag Warning until 8 PM CDT this evening for SDZ006>008- 011-018>023. MN...Red Flag Warning until 8 PM CDT this evening for MNZ039-046.