textproduct: Aberdeen

KEY MESSAGES

- Frost/Freeze expected tonight/Wednesday morning (28 to 33 degrees) between the Missouri valley region east into the Sisseton hills region.

- Another round of moisture mainly Friday. Lower and upper range for moisture is just a few hundredths to a 1/2 inch.

- Turning warmer late weekend/early next week, about 10 to 20 degrees above normal (Highs: 80s to near 90).

UPDATE

Issued at 620 AM CDT Tue May 19 2026

UPDATE for 12Z Aviation discussion.

DISCUSSION

Issued at 130 AM CDT Tue May 19 2026

Will leave the frost advisory in place though temperatures still in the low 40s/upper 30s with cloud cover and mid/upper 30 dewpoints, and northwest winds gusting to 15 to 20 mph making frost highly unlikely expect in the most protected/drainage prone areas.

Focus for freeze conditions continues tonight with high pressure shifted a little east in comparison to previous forecasts, centered over the Sisseton hills region. This still makes us ground zero for a frost/freeze. From the Missouri river and north of highway 14 NBM temperatures are still down around 30F. NBM upper bound (90th) even has lows in the low/mid 30s so at a minimum a frost. And the NBM has been consistent, leaving little doubt that the area will experience these cold temperatures and related impacts.

Additionally, daytime heating still showing up in NAM/GFS/RRFS BUFKIT profiles with shallow CAPE between 2 to 3kft up to about 6kft. Cloud cover dissipates with loss of daytime heating. Evening temperatures are only expected to top mid 50s. Did bring back the mention of sprinkles as well.

Aside from frost, some evidence for fog under the high given recent moisture and cool temperatures/lack of mixing.

Focus shifts to additional rain chances late Thursday through Friday with southwest flow and then a negatively tilted shortwave. After that flow becomes more zonal and then another trough sets up out west for early next week. This flow regime results in milder temperature trends with NAEFS 850mb temperatures increase to a standard deviation above climo. NBM highs Sun-Tues some 10 to 20F above climo, though starting Friday the NBM 25th/75th range in temperatures begins to expand to 7 to 10 degrees suggesting lower confidence.

AVIATION /12Z TAFS THROUGH 12Z WEDNESDAY/

Issued at 620 AM CDT Tue May 19 2026

Terminals KABR,KATY,KPIR,KMBG

VFR to MVFR ceilings remain over the area, with pockets of clearing. This is resulting in larger TEMPO groups for the first few hours. Expect VFR ceilings at all locations by around 19Z, holding out longest at ATY.

ABR WATCHES/WARNINGS/ADVISORIES

SD...Frost Advisory until 9 AM CDT /8 AM MDT/ this morning for SDZ003>005-009-010-015-016-033>035-045. Freeze Warning from 11 PM this evening to 8 AM CDT Wednesday for SDZ004>011-016>023-034>037-051. MN...None.