textproduct: Aberdeen

KEY MESSAGES

- A wind advisory has been issued for areas west of the James River today. Sustained winds have a 50-80% chance of being 30mph or more during the afternoon with a 40-60% chance for winds to gust up to and over 45 mph.

- There is Slight (2 of 5) to Marginal Risk (1 of 5) for severe weather Saturday. Confidence is low on storm development due to very warm temperatures above the surface. If storms do form, it will most likely be in the evening to overnight hours. These storms could have large hail of up to 2 inches in diameter and wind gusts of 60-70 mph, and a tornado or two developing cannot be ruled out.

- There is a Marginal (1 of 5) risk for severe weather Sunday along the ND/SD border. Again, confidence is low for storm development during the day, but once we move into the evening and overnight hours, severe storms will be possible. Main hazards are large hail and isolated wind gusts of 60 mph.

- Above normal temperatures for Sunday and into next week. Temperatures are forecast into the 90s and dewpoints well into the 60s. This will push heat index values into the mid to upper 90s, with increased risk for heat related illnesses.

DISCUSSION

Issued at 141 AM CDT Sat Jun 27 2026

There is a 15-25% chance for some scattered showers into the morning before things clear up into the early afternoon. As this is happening, a high surface pressure is settles over the Great Lakes region today and lower surface pressure to the west over MT/WY. This will help to tighten the pressure gradient over SD a bit, and increase winds Saturday aloft. With lapse rates increasing during the mid-morning through the afternoon, these stronger winds will be able to get to the surface. Southeasterly winds will be moving into SD with a 50-70% chance for the winds to be sustained at or above 30 mph with a 40-60% chance for gusts of 45 mph or more mainly in north central SD and areas west of the Missouri River. A wind advisory had been issued for this area because of these winds. These strong winds could make driving difficult, especially for high profile vehicles.

The southeast winds will be pushing lots of moisture into SD today and with instability building through the day (NAM has MLCAPE values in the 2000-3000 J/kg over central SD during the evening). While there is a good environment for severe storm development, models are showing higher CIN values through the afternoon and into the evening over central and northeastern SD, which will helps to show the cap in the atmosphere that will stop storms from developing. Weaker CIN values to the west could cause storms to develop in western SD and then move into/develop over central SD during the late evening into the overnight hours when CIN values weaken over central SD. High-res models show some scattered storms moving into central SD during the late afternoon but not lasting too long. Then more storms move in during the late evening/early overnight hours with a few models showing a few more storms trying to develop over central SD overnight behind the earlier cells as they move east.

There is a slight risk (level 2 out of 5) for severe storms over central SD today, and a marginal risk (level 1 out of 5) over northeastern SD and west central MN. While there is lower confidence in the timing of these storms due to the cap of warmer air aloft, the main threat timing looks to be during the evening and overnight. With stronger lapse rates and shear being forecast, large hail (up to 2 inches in diameter) and strong winds of 60-70 mph will be possible in the storms. Additionally, with the shear available, a tornado or two developing, mainly over areas west of the Missouri River, cannot be ruled out. With the storms occurring overnight and moving east, some lingering weak storms and showers will be possible Sunday morning over northeastern SD and west central SD as the storms dissipate or move out of SD.

Sunday, the surface low is forecast to move over western SD and will create a similar environment for severe storm development over central and northeastern SD. While there will be higher CAPE and shear values to aid in severe storm development, the CIN again looks to be high, with a stronger cap to stop storm development during the afternoon into the evening. While confidence in timing is low again on Sunday, models are hinting at a weakening cap during the late evening and overnight hours which would allow for storms to develop during those times over central and northeastern SD. There is a marginal risk (level 1 out of 5) for severe storms. The main threats in these storms will be hail up to 1 inch and winds gusting up to 60 mph.

While the surface low is moving into SD Sunday, a high pressure is setting up to the east . This high pressure and southerly winds will help to move warmer temperatures into SD during the end of the weekend into the beginning of the work week. Models have scaled back on how hot eastern SD will be getting compared to previous runs, moving the heat to the east. While the models have scaled back slightly, it will still be hot out Sunday and Monday. Heat index values will be in the low to mid 90s Sunday afternoon areas in the James River Valley and to the east, and Monday will be in the low to upper 90s east of the Prairie Coteau. In addition to the heat trying to move into SD on Sunday, some models are forecasting a little bit of smoke from the wildfires to the southwest to move in Sunday morning behind the storms. At the moment, this smoke looks to stay aloft over western and north central SD, and could cause some milky/hazy looking skies in north central SD Sunday morning after the storms move through.

AVIATION /06Z TAFS THROUGH 06Z SUNDAY/

Issued at 1237 AM CDT Sat Jun 27 2026

Terminals KABR,KATY,KPIR,KMBG

Showers and storms west of the MO River to start the period are moving into a less favorable environment for continued growth. Still, storms are expected at PIR for the first couple of hours, and at least temporarily at MBG. Otherwise, VFR conditions will dominate much of the period, with winds being the main concern with gusts of 28-38kts Saturday afternoon - lightest at ATY. We will be monitoring again for the introduction of storms late Saturday afternoon into Saturday night.

ABR WATCHES/WARNINGS/ADVISORIES

SD...Wind Advisory from 10 AM CDT /9 AM MDT/ this morning to 7 PM CDT /6 PM MDT/ this evening for SDZ003>005-009-010- 015>017-033>037-045-048-051. MN...None.