textproduct: Aberdeen

KEY MESSAGES

- There is a Slight (2 of 5) to Marginal Risk (1 of 5) for severe weather mainly tonight across the central/north central SD portion of the forecast area. Severe storms will be possible tonight into Monday morning. Main hazards are large hail up to 2 inches in diameter and wind gusts of 60 mph.

- Western U.S. wildfire smoke (aloft) will be over the region through Tuesday; potentially longer depending on how steering flow winds evolve this week. Some minor concentrations of near surface smoke could happen from Monday afternoon through Monday night.

- There is a Slight (2 of 5) for severe weather on Monday mainly across north central SD. There is a Marginal Risk (1 of 5) for severe weather Monday evening across the far eastern edge of the forecast area. Main hazards are large hail up to 2 inch in diameter and wind gusts of 60 mph.

- Temperatures are expected to warm into the 90s, with dewpoints in the 70s, across far northeast South Dakota and west central Minnesota on Monday. The net result is heat index temperatures running up into the 100F to 105F degree range for several hours Monday afternoon. A Heat Advisory has been issued to address this concern.

- Above normal temperatures are expected to persist for most of this week. With highs in the upper 80s to mid 90s and dewpoints well into the 60s, and even 70s for some locations, especially from Wednesday onward, heat-related illnesses become a concern.

UPDATE

Issued at 801 PM CDT Sun Jun 28 2026

Quiet conditions across the CWA for now as any spotty rain showers over far NESD is continuing to diminish as we get closer to sunset. A pair of splitting supercells lies to our north near Bismark and south over northern NE. Storms are still expected to fire up over south central/central SD later on this evening and track northeast per another jet streak/shortwave energy rounding the closed low over MT/Canada and to the north and northwest of a low that will track northward into SD out of Colorado during the overnight hours. With the help of MUCAPE of 1000-2000 j/k, bulk shear of 50-70kts, and overall elongated hodographs. Elevated supercells (splitting supercells) will be the main threat with perhaps a few clusters as well. With the elevated nature and steep mid level lapse rates, large hail of 2+" is possible along with wind gusts in excess of 60 mph. Especially if we get gravity wave associated convection, then wind gusts could exceed 80+mph. For example, the latest HRRR has a cluster of cells moving in or developing over Jones County after midnight and quickly tracking northeast, potentially over Pierre during the overnight hours. Other then minor grid updates, the forecast remains on track.

UPDATE Issued at 619 PM CDT Sun Jun 28 2026

Updated discussion for the 00Z TAFs below.

DISCUSSION

Issued at 127 PM CDT Sun Jun 28 2026

At 1 PM CDT, skies are mostly sunny, with some smoke aloft noted on geo-color GOES satellite imagery. Temperatures were warming through the 70s into the low 80s on a south-southeast wind around 5 to 15 mph with occasional gusts to 25 mph.

The table is set for late night convection, initially, across portions of western/central South Dakota where a synoptic scale frontal boundary resides. Upper level energy lifting northeastward into the region will be bringing some higher end mid-level WAA into the CWA between 06Z and 15Z, about the same time it's surface low reflection is working up along the frontal boundary/lee-of-the- Rockies surface trof. All this is expected to be occurring basically near/under a 90-110kt upper level jet streak extending from northwest North Dakota back to western Nevada, so plenty of upper jet dynamics support for a convective event tonight too. Not ruling out potentially damaging thunderstorm wind gusts. But mainly concerned about hail and heavy rain tonight into Monday morning. RAP/NAM low level moisture progs of +13C to +16C (or higher) line up along/ahead of this boundary/within this surface low overnight into Monday morning. SPC continues Slight Risk/Marginal Risk coverage over this CWA in their Day 1/Day2 Convective Outlooks for later tonight into the first half of Monday.

As the boundary/surface low continue to progress east and north, the boundary layer should dry out as winds switch around to a west- northwest wind direction. Surface pressure rises kick in late in the day Monday and persist into Tuesday as surface high pressure gets sandwiched in between lower pressure to the north (across southern Canada) and the aforementioned surface front/trof that will be stalling out across northwest Kansas and Nebraska heading into Tuesday morning.

Without getting lost in the weeds, looking ahead to Tuesday night/Wednesday morning, will be monitoring trends in the models for late night WAA-forced/mid-level short-wave-lifted convection along/north of that stalled-out synoptic-scale boundary to the south that may be trying to work slowly back to the north Tuesday night/Wednesday as a warm front. Beyond that, qpf clusters analysis, complimented by the deterministic GSM's, still showcase at least 2 or 3 more decent chances at precipitation between Thursday and the Monday after the 4th of July holiday weekend. The pattern aloft still tries to push the persistent downstream upper ridging over the Great Lakes region back to the west late in the period. And that continues to support the above to, potentially, much above normal temperatures and humidity in the forecast. HeatRisk output and Apparent T values will continue to be monitored. The latest wrinkle is apparent T values running up into the low 100s tomorrow (Monday) along and east of the SD/MN border in the afternoon. Heat Advisory is in effect to handle this.

AVIATION /00Z TAFS THROUGH 00Z TUESDAY/

Issued at 619 PM CDT Sun Jun 28 2026

Terminals KABR,KATY,KPIR,KMBG

Conditions continue to be VFR, but guidance depicts sub VFR stratus/strato-cu working its way northward into the TAF sites later this evening and overnight along with the possibility of patchy fog east of the Missouri River. After 06Z tonight, there could be strong to severe thunderstorms working northeast toward the KPIR/KMBG terminals. By the late morning/midday (~15-18), the last of the convective potential should be shifted up across North Dakota. Of note, periods of smoke aloft will filter in from the southwest and track east/northeast through the TAF period.

ABR WATCHES/WARNINGS/ADVISORIES

SD...Heat Advisory from noon to 8 PM CDT Monday for SDZ008-021. MN...Heat Advisory from noon to 8 PM CDT Monday for MNZ039-046.