textproduct: Aberdeen

KEY MESSAGES

- A Slight Risk (level 2 out of 5) for severe weather is in place over portions of south central SD Thursday. A Marginal Risk (level 1 of 5) for severe weather is in place for the rest of the forecast area. The main hazard will be wind gusts of 60 to potentially 70 mph and hail of one inch in diameter.

- Through Friday morning, much of northeastern South Dakota and western Minnesota may see around 1.5"-2" of rain. Localized areas of 3"-4" may be possible, and Flash Flooding will be possible in places that see these higher end rainfall totals.

- Temperatures into the upper 90s to low 100s return over parts of central and north central South Dakota this weekend. Temperatures are set to cool down to below normal by the middle of next week.

UPDATE

Issued at 644 AM CDT Thu Jul 30 2026

UPDATE to 12z Aviation discussion.

DISCUSSION

Issued at 251 AM CDT Thu Jul 30 2026

Keeping an eye on some rain showers and weak storms early this morning as they track east across central South Dakota. Currently (~07Z) this system is producing 30-40 mile per hour winds. Environmental parameters, namely DCAPE and low-level lapse rates for assessing the potential wind threat, have decreased over the past few hours. At this point there is little concern for severe weather over the next few hours.

Main forecast focus today will be the storms through the day, produced by a shortwave aloft embedded within the broad upper-level ridge dominating the pattern. Storms will remain possible this morning, but severe chances increase beginning this afternoon and continuing into the evening. Signal in high-resolution model guidance is for multiple potential areas of development during the afternoon - one over northeastern South Dakota and another over central South Dakota. In both areas, there will once again be under a low CAPE/Shear environment (roughly 1000-1500 J/kg and 20-30 knots of shear), so storms will likely have a difficult time producing severe hail. For that same environmental reason however, collapsing storms may produce severe winds at times. There are some potential limitations to those chances however. First, the DCAPE environment will be less than impressive, and hi-res CAMs show a struggle to reach 1000 J/kg. Additionally, due to the cloud cover and rain through the morning, diurnal heating will be somewhat limited over most of the forecast area. This will keep low-level lapse rates well below dry adiabatic, providing another potential obstacle for potential severe winds to overcome. At this time, a Marginal Risk blankets the forecast area, with the addition of a Slight Risk over parts of south central South Dakota.

With storms today there is also a Slight Risk for Excessive Rainfall covering northeast South Dakota and western Minnesota. Over this area, the latest ensemble guidance is fairly consistent in median 24 hour rainfall totals (ending Friday morning) around 1.5"-2" over parts of eastern South Dakota and western Minnesota. The one exception would be the NBM, which pushes median values up over 2". 90th percentile values, a reasonable "worst case scenario", have rainfall totals around 3-4". One potential saving grace is that soils over that area (and really the entire forecast area) are fairly de-saturated. Therefore, the ground should hopefully be able to take a bit of rain before flooding occurs. The flip side is that 3-4" over 24 hours is the point at which flooding tends to occur (based on local research), so if these higher end values verify, flooding is certainly a possibility this evening.

Southerly winds this morning will help push most if not all of the remaining near-surface smoke out of the area and to the north. Therefore, expect air quality to remain good this afternoon. Smoke aloft will also be mostly out of the area today, although with cloudy skies all day that will be not much of a concern anyway. However, smoke aloft will likely move over at least part of the forecast area once again on Friday. Near surface concentrations may also reach Moderate levels again, and minor visibility reductions may become possible. Coverage of the highest near-surface concentrations Friday does not appear to be very broad at this point in time.

As the shortwave moves out, the upper-level ridge in place will become more positively tilted, leading to a bit of a temperature gradient over the CWA over the weekend. Near-normal temperatures will be in place over the east, but central and north central South Dakota are once again set to reach the upper 90s to 100s, particularly on Sunday.

The next chances for rain will come early next week after the dry weekend. The upper-level pattern will shift as a trough pushes down over the Pacific Northwest and Northern Plains. With this trough will come a jet streak aloft, and the potential for storm development as a result. Given the extended time frame, diving into the details would be fruitless at this point other than to say that extended model guidance shows some potential for the equivalent of a Marginal Risk for severe weather over the area. This pattern shift will also bring about a cooler airmass over the Northern Plains, and below normal temperatures will be likely (70-90% chance of highs below 85 degrees) Tuesday and Wednesday.

AVIATION /12Z TAFS THROUGH 12Z FRIDAY/

Issued at 644 AM CDT Thu Jul 30 2026

Terminals KABR,KATY,KPIR,KMBG

We are starting out with VFR conditions. Near surface air quality has improved over central SD (MBG/PIR) into the Good category, but remains in the Moderate/yellow category for ABR/ATY. Visibility restrictions have been down to 6SM at ABR, but mainly due to temporary morning fog. Forecast solutions show increased precipitation as early as 14Z at ABR, and ATY by 16Z. Have -TSRA only mentioned in PROB30 groups at this point due to the lower confidence. MVFR to IFR ceilings will develop for all but MBG overnight. Moderate to heavy rain will stay mainly southwest of MBG through the period.

ABR WATCHES/WARNINGS/ADVISORIES

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