textproduct: Aberdeen

KEY MESSAGES

- Fast moving system overnight tonight comes with a 50/50 chance for about 1/4" of moisture. Weak thunderstorms are unlikely to produce severe weather during the overnight hours.

- Marginal Risk (1 of 5) for isolated severe storms Tuesday afternoon/early evening along and east of the James valley into western Minnesota. Main threats include wind gusts of 60 mph and quarter sized hail.

- Temperatures remain near to slightly below normal through the work week. More seasonal temperatures and humidity return late week into next weekend.

UPDATE

Issued at 347 AM CDT Mon Jun 22 2026

UPDATE for 12Z Aviation update below.

DISCUSSION

Issued at 108 AM CDT Mon Jun 22 2026

Subtle kink in 500mb flow suggests subtle wave crosses the area today. NBM did populate with some blotchy POPs, though not seeing much in soundings to indicate mid-level clouds or instability aside from some altostratus in the HRRR/RAP at between 7-10kft and thats not going to do it.

Focus is mainly on moisture/thunder potential with the wave crossing the region tonight. Diffluent flow aloft ahead of the wave coming in across the Norther Rockies to help support thunderstorms during peak heating across MT/WY with some CAMS supporting isolated convection in the Western Dakotas. Aside from the ARW which is generating some weak convection associated with minor warm advection we're seeing in the NAM/GFS/Canadian across the northeast, CAMS keep us dry through about midnight. Flow aloft increases to about 50kts, however at 700mb and below its closer to 10 to 20kts. BUFKIT profiles also show skinny CAPE as the system and warm advection assisted convection move across the area. This will limit the severe weather threat as well as intensity of any precipitation. Trends from the HREF probabilities suggest as such, with most of the area below a 50/50 chance at seeing 1/4".

Later Tuesday however, 700mb temperatures remain quite mild for this time of year, dewpoints have increased into the 50s to near 60F. Flow below 500mb has also increased with the upper low to our north. Thus its a case of daytime driven instability with unidirectional shear similar to what we've seen for much of early June and comprises of mainly a wind/hail threat.

Northwest flow aloft continues into Wednesday, however low level flow is more northerly and surface dewpoints mix out in the 40s limiting instability. 700mb temperatures are at their coolest Wednesday/Thursday, after which we see mid level warm advection as another west to east wave moves into the Northern Rockies. That system is oddly like the wave from Sunday, and models have it decay as it moves across the Dakotas. Will wait till it gets closer before we start talking about moisture probabilities.

Then we look towards the west for a stronger upper low that drops into the Pac NW Saturday and traverses the Norther Rockies, lifting out in Montana and south central Canada Sunday night. A comparison of 700mb temperatures indicate the GFS has tempered in comparison to 24 hours ago, while the GEFS has increased to about +12C (1 standard deviation above climo) however these are still higher in comparison to the Canadian/EC. Also continue to see the return signal for Gulf moisture as surface dewpoints return well into the 60s.

AVIATION /12Z TAFS THROUGH 12Z TUESDAY/

Issued at 347 AM CDT Mon Jun 22 2026

Terminals KABR,KATY,KPIR,KMBG

VFR conditions will dominate at all locations through the period. The main concern will be at PIR, where MVFR to IFR ceilings have remained just southwest of the site. The latest forecast trends have indicated that most of these lower clouds will remain southwest of PIR. As a result, TEMPO MVFR ceilings looked most reasonable 13-17Z. Light showers and isolated thunderstorms are possible overnight, remaining below a 30% chance prior to 06Z, with a 40-60% chance of showers and a few thunderstorms prior to 12Z at PIR and MBG.

ABR WATCHES/WARNINGS/ADVISORIES

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