textproduct: Aberdeen

KEY MESSAGES

- High temperatures will be about 10 to 15 degrees below average through the weekend. Slightly colder highs for Sunday, ranging from 10 degrees to the upper 20s. A warm up is expected Monday and Tuesday.

DISCUSSION

Issued at 1201 PM CST Sat Feb 21 2026

A persistent upper low over southern Canada continues to wrap some clouds back into northeast SD and west central MN today. The upper trough digs in even further tonight and may help regenerate some stratus/flurries near the Sisseton Hills. Below normal temperatures persist Sunday as that upper trough and northerly sfc flow reinforce the colder air. Drier mid levels west of the James Valley and a 70 kt jet will lead to breezy wind gusts Sunday.

By Monday, return flow sets up from the James Valley west under a building upper ridge. Temperatures will rebound a little Monday with a bigger warm air advection push on Tuesday. Stuck with the grand ensemble Tuesday night into Wednesday as precipitation chances move back in. An arctic front slides south late Tuesday. There is still a lot of model spread regarding placement and timing and resultant P- type and amounts with both the arctic front and then a warm air advection band off a Black Hills/Nebraska low on Wednesday. Behind this mid week low, windy and dry westerlies take hold for the end of the week.

So, a split flow pattern has developed along and west of the U.S. west coast at the start of the period, with an upper level ridge downstream of it over the U.S. Rocky mountains. From Thursday through Friday night, the split flow pattern is forecast to evolve into more of a unified/connected steering pattern that showcases a broad (not overly amplified) upper level ridge stretching from coast to coast. Deterministic GSM's and ensemble clusters analysis suggests that it could take from Saturday to Tuesday morning to move the upper level ridge axis to a position east of the CWA, while new upper level trof/energy digs out a new west coast longwave trof. At some point after 12Z Tuesday of next week, some scrutiny will be needed interrogating potential chunks of low pressure energy (potential rounds of precipitation) lifting out of this western CONUS longwave trof.

So, besides a small (20-40 percent) chance of precipitation Tuesday, the extended forecast period is dry and warm. S.A. Ensemble tables for both GFS and ECMWF ensemble systems show, at least, 1 standard deviation above normal 850hpa temps for most of the period. And, 25th to 75th percentile ranges for temperature are rather small, lending confidence to the continued above normal temperature forecast being advertised.

AVIATION /18Z TAFS THROUGH 18Z SUNDAY/

Issued at 1201 PM CST Sat Feb 21 2026

Terminals KABR,KATY,KPIR,KMBG

VFR conditions are expected to prevail over the next 24 hours. KATY may see a brief intrusion of MVFR cigs this evening before clearing again. Confidence is too low to add a tempo group at this time.

ABR WATCHES/WARNINGS/ADVISORIES

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