textproduct: Aberdeen

KEY MESSAGES

- Warming trend in place through mid-week, with temperatures persistently above average through the end of the 7-day forecast. Tuesday could see highs reaching or exceeding the 90F degree mark (15 to 20 degrees above normal) in some places again. The rest of the week should see highs in the 80s.

- Some isolated to scattered showers and thunderstorms could develop or move over portions of south central and east central South Dakota later tonight, with low probability (less than 30 percent) chances of rain extending into the daytime hours on Tuesday.

- Isolated to scattered evening and overnight thunderstorm chances (20-40 percent chances) exist off and on from Friday through Sunday.

DISCUSSION

Issued at 143 PM CDT Mon May 25 2026

At 1 PM CDT, temperatures are warming through the 80s, on their way into the low 90s in some spots. Skies are sunny or sunny through some high clouds and winds are south to southeast around 5 to 10 mph with gusts up to 20 mph at times.

Got another set-up tonight where the nose of a llj is expected to be creeping northward toward the CWA border region with neighboring FSD. Low level moisture advection is expected to accompany this llj overnight, such that there may be a few hours where the two coincide (best llm advection on the nose of the best llj forcing) and some isolated to scattered thunderstorm chances can happen. Mid-level (700hpa) temps are also steadily climbing to around +7C to +9C tonight. No clearly discernible mid-level shortwaves tonight, though. Will have to wait and see if mid-level WAA on the nose of the llj will be sufficient to get some accus-storms to pop.

Low to mid-level WAA continues during the day on Tuesday. Kinda odd to see during daytime hours, but models prog the (0.5km) llj to persist across part of the CWA on Tuesday as well. Noticed a few of the CAMS are generating a handful of showers and thunderstorms around the northern/eastern forecast zones during daytime heating on Tuesday, presumably due to the combination of ongoing low level WAA/llj activity. The CWA is also progged to be sitting directly under a mid/upper level ridge on Tuesday. The upper level longwave trof currently just off the west coast will close off and sit and spin over the desert southwest on Tuesday. Beyond that, models continue to try and resolve split flow aloft, with a blocky west- east trof/ridge pattern stuck under it. Overall, the pattern continues to support plenty of low level moisture/instability around during the second half of the week, potentially into the weekend. Limited deep-layer shear, though. So, wherever, lee-of-the-Black- Hills surface trofs set up each afternoon during peak heating, or wherever any lingering/remnant OFB's can become a localized source of low level forcing, thunderstorm chances will exist out in the out periods (20-40 percent chances). Ensemble QPF clusters analysis continues to support a couple of chances for precipitation, mainly between Friday night and Sunday. No major cold air intrusions noted in the models, but the warmest air around in the 7-day forecast appears to be aligning with today and Tuesday, possibly lingering into Wednesday, per deterministic thermal progs and Ensemble (NAEFS/ENS) S.A. table 850hpa standardized anomalies.

AVIATION /18Z TAFS THROUGH 18Z TUESDAY/

Issued at 1213 PM CDT Mon May 25 2026

Terminals KABR,KATY,KPIR,KMBG

Good VFR is forecast at all four terminals through the 24 hour TAF valid period.

ABR WATCHES/WARNINGS/ADVISORIES

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