textproduct: Aberdeen

KEY MESSAGES

- Frost/freeze expected early Wednesday morning across the region as lows drop into the upper 20s to low 30s.

- Rainfall chances increase to 60-70% on Friday. Amounts generally between 0.25-0.75in and very limited threat for severe storms.

- Turning warmer late weekend/early next week, about 10 to 20 degrees above normal with highs in the 80s to near 90.

DISCUSSION

Issued at 231 PM CDT Tue May 19 2026

Plenty of stratocumulus clouds remain across the CWA this afternoon, but with high pressure and drier air working into the region into this evening, expect gradual clearing from west to east. Winds will also become light and variable this evening before switching to the south-southeast late tonight. Rather good radiational cooling conditions setting up tonight, especially over the eastern CWA. Expecting temperatures to drop into the upper 20s to low 30s across most of the CWA, so will therefore stick with the frost/freeze headlines. Frost advisories were buffered around the original Freeze Warning.

On Wednesday, surface high moves east into MN while a surface trough takes shape over eastern MT and WY. This will tighten the pressure gradient across SD, especially central SD where southerly winds are likely to gust between 30 and 40 mph by late morning. Don't see a need for an advisory at this point as even NBM90 wind gusts are below 45 mph.

Focus then shifts to the approaching upper trough and associated surface trough/low that moves into the region Thursday night through Friday. Models starting to come into better agreement with increasing chances (60-70%) for rainfall across the region. Instability looks somewhat limited though and SPC outlook, as well as ML outlooks don't highlight any severe storm potential over the Northern Plains. As for rainfall amounts, NBM mean-75th spreads in a 48-hr time frame ending at 12Z Saturday generally range from around 0.30in to 0.75in.

Warming trend still showing up in the models towards the latter half of the weekend into early next week as Grand Ensemble 850mb temps increase to around +15C to +18C across the CWA during this time. Inherited NBM high temps are in the 80s Sunday through at least Tuesday of next week.

AVIATION /18Z TAFS THROUGH 18Z WEDNESDAY/

Issued at 1230 PM CDT Tue May 19 2026

Terminals KABR,KATY,KPIR,KMBG

CIGs have generally improved to VFR early this afternoon and are expected to remain that way through the remainder of the day before SKC conditions take over tonight. Light winds tonight will increase from the south on Wednesday with gusts close to 30 knots across central SD (KPIR/KMBG).

ABR WATCHES/WARNINGS/ADVISORIES

SD...Frost Advisory from 1 AM CDT /midnight MDT/ to 8 AM CDT /7 AM MDT/ Wednesday for SDZ003-015-033-045-048. Freeze Warning from 1 AM to 8 AM CDT Wednesday for SDZ004>011- 016>023-034>037-051. MN...Frost Advisory from 1 AM to 8 AM CDT Wednesday for MNZ039-046.