textproduct: Aberdeen

KEY MESSAGES

- The Northern Plains will see an active pattern, and chances for showers and thunderstorms are in place through the weekend and into at least the start of next week.

- Through early Sunday morning, chances of a quarter of an inch of rain range from 10-20% over northeastern South Dakota and western Minnesota, increasing to 70-80% over central South Dakota.

- There is a Marginal Risk (Level 1 of 5) for severe weather Saturday evening and Saturday night across central and parts of north central South Dakota. Jones County, as well as parts of Lyman and Stanley Counties reach a Slight Risk (Level 2 of 5). Damaging wind and hail of one inch in diameter are the main threats.

- There is a Marginal Risk (Level 1 of 5) for severe weather Sunday, mainly along and west of the James River Valley. Damaging wind and hail of one inch in diameter are the main threats.

UPDATE

Issued at 1018 AM CDT Fri May 29 2026

As of 10am, temperatures range in the upper 60s to the mid 80s with the warmest temps over far northeastern SD into west central MN as these locations are more under the ridge and less cloud cover. Satellite indicates broken to overcast skies west of here as radar indicates light rain showers and/or sprinkles mainly between the Mo and James River as winds at 850mb to surface are from the southeast with ongoing moisture surging north/northwestward from the Gulf with dewpoints in the upper 50s to the lower 60s. Forecast remains on track for the rest of the day as we will continue with this moisture surge into the CWA. Along with daytime heating, scattered on again off again light rain and isolated weak thunderstorms are possible across the CWA. With lack of CAPE, shear, and weak lapse rates, no severe weather is anticipated.

UPDATE Issued at 636 AM CDT Fri May 29 2026

See below for an aviation forecast discussion for the 12Z TAFs.

DISCUSSION

Issued at 244 AM CDT Fri May 29 2026

Broad upper-level ridge that has previously allowed such warm temperatures to take hold will finally begin to progress to the east. An upper-level trough to the west will begin to exert influence over the region for the next few days, and the corresponding height falls will drop highs to be in the low to mid 80s (still about 5-10 degrees above normal for this time of year). Near-surface to low-level pressure gradient is also expected to increase today, leading to a southerly low-level jet over the region. During the afternoon, gusts from the jet will mix to the surface, topping out around 30-40 miles per hour. Strongest winds are expected along and west of the Missouri River, particularly over north central South Dakota. As the low-level jet progresses eastward on Saturday, expect more widespread windy conditions during the afternoon, with gusts once again reaching 30-40 miles per hour.

Showers arrive this morning along the low-level jet, moving up into the region from the south. Coverage is generally expected to be spotty through the day today, with precipitation rates remaining fairly light. Most of the forecast area (with the exception of far northeastern South Dakota into western Minnesota) has a roughly 20- 40% chance to see a tenth of an inch of rain through tonight. Rain showers are expected to continue through the overnight period and into Saturday as well. Some heavier rainfall in the form of thunderstorms will move over central South Dakota Saturday, with the potential for a quarter to half an inch to fall through Saturday night in that area.

In terms of the severe weather potential Saturday evening, the setup does not appear to be very impressive at the moment, but can't rule anything out at this time. The best chances for the severe threat are located in south central South Dakota, where a Marginal to Slight Risk is in place. A plume of CAPE extends up into the region, and while the main axis and highest values remain to the south and west, around 1000-2000 J/kg will clip the western part of the forecast area. Shear does not appear to be very favorable, just 20- 25 knots in the area, but hail may still be a possible hazard with 700-500mb lapse rates around 6.5-7 C/km. Wind is also a possible hazard, as DCAPE values will reach over 1000 J/kg at times. With the weak shear likely producing short-lived storm that collapse quickly a microburst or two may be possible, but low-level lapse rates appear unfavorable at the moment, just 6-7 C/km. Can't rule out tornado potential either at the moment, as there is some indication of the potential for an area of low-level shear of 20+ knots, LCLs below 1000m, and 0-3km Helicity over 200 m^2/s^2 to overlap. Given the time frame, not many high-resolution guidance is currently available, so this assessment may shift over the next couple of forecast cycles as the time frame comes into the time range of more models.

An active pattern is expected to continue into next week with the upper-level trough sitting over the western CONUS and placing the Northern Plains in the left exit region. Therefore, support for showers and storms will continue into next week. Nothing stands out at this point in terms of severe weather potential, so will save the analysis on potential threats next week for future forecasts and discussions.

AVIATION /12Z TAFS THROUGH 12Z SATURDAY/

Issued at 636 AM CDT Fri May 29 2026

Terminals KABR,KATY,KPIR,KMBG

KABR and KATY are forecast to prevail in VFR conditions. For KPIR, the first half of the TAF valid period is forecast to be VFR. However, increasing low level moisture later today into tonight and Saturday means there is an increasing chance for sub-VFR low clouds to develop/move over KPIR/KMBG terminal airspace after 00Z Sunday, particularly at KPIR. There are also expected to be occasional showers moving north across the region today into tonight, which could pass over any of the four terminals. While there is limited impact expected from these showers, briefs dips into MVFR visibility in rain are possible. South or southeast winds are forecast during the TAF valid period, 15 to 25 knots with gusts up to 35 knots at KPIR/KMBG and 5 to 15 knots with gusts up to 20 knots at KABR/KATY.

ABR WATCHES/WARNINGS/ADVISORIES

SD...None. MN...None.