textproduct: Aberdeen

KEY MESSAGES

- A Slight Risk (level 2 out of 5) for severe weather is in place over portions of central and south central SD this afternoon and tonight. 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 60-70 mph and hail of one inch in diameter.

- Through Friday morning, much of northeastern South Dakota and western Minnesota could see around 1.5"-2" of rain. Localized areas of 3" or more inches could 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 628 PM CDT Thu Jul 30 2026

Heavy rain and flooding continue across the forecast area, especially across northeast SD and west central MN. Even as one area of heavy rain moves or dissipates, there are more waiting in the wings and expected to move through tonight. Heaviest rain amounts have ranged from 5 to 7 inches across northern Day county.

DISCUSSION

Issued at 253 PM CDT Thu Jul 30 2026

The main challenges in this forecast package will continue to revolve around the chances for severe weather and locally heavy rainfall the remainder of today into tonight and Friday morning. Mid afternoon satellite/radar imagery indicate ongoing active weather across this forecast area. Showers and thunderstorms have continued to evolve across northeast SD/west central MN early this afternoon while the area of showers/storms the moved across south central SD through the first half of the day have shifted into southeast SD. development of more robust convection has taken place over the last hour or so across parts of far south central SD, south of the I-90 corridor. This activity appears to be shifting east-southeast and may clip our far south/southwest zones this afternoon where a Severe Thunderstorm Watch has been issued until 9 PM CDT tonight.

The disturbance partly responsible for this active pattern today is in the form of a mid level shortwave trough that is working into western SD this afternoon. The lead shortwave ahead of this feature was responsible for this mornings activity has shifting east and southeast. This upper level disturbance is encountering a modestly unstable air mass with MLCAPE values ranging between 2000-3000 J/kg. So, there's enough instability for storms to continue. However, deep layer shear remains mostly lacking across most of our CWA, outside of far southern zones and perhaps near the ND/SD border region where 0-6 KM bulk shear values range between 25-30 kts. Weak flow in the low to mid levels of the atmosphere have played havoc on the evolution of convection and thus hi-res guidance has had a tough time discerning what comes of all of this. Also, outflow boundaries created by existing or earlier convection is also playing or will play a role in future storms as the latter half of the afternoon and evening wear on. So, best chances for severe weather for the remainder of this event the rest of today and tonight will be across parts of central and south central SD. Initial discrete cells will be capable of large hail but with time, storms will evolve into more clusters or linear mode and the threat will become damaging winds. Perhaps the more widespread threat across most of the forecast area will be locally heavy rainfall. A Slight Risk for Excessive Rainfall remains posted for most of the forecast area with our eastern half of zones having the best chance for seeing 1-2 inches of rainfall. Some localized amounts of 3 inches or more will be possible, especially from parts of west central MN into east central SD south and west into sections of the James Valley and far south central SD. These area will have the best chance to see localized flash flooding with any storms. The slow moving nature of this convection will only help contribute further to the flooding possibilities.

The upper level disturbance shifts south and east of the area on Friday. Lingering rains across our eastern zones will diminish by midday leaving drier condition to settle in during the afternoon. High pressure building in from the north will lead to breezy north to northeast winds on Friday. Temperatures will remain close to normal if not slightly below normal(especially eastern zones) on Friday. Upper ridging is progged to build into the region through the course of the upcoming weekend. This will bring back the heat to the region, especially across central SD. Temperature progs indicate those locations will be back into the 90s to around 100 degrees Saturday into Sunday and to a certain extent on Monday. Southerly flow returns and with a tighter gradient developing by late in the weekend and a drier air mass, elevated fire weather conditions are expected to develop across parts of central and north central SD. After another fropa early next week, a cooler than normal air mass will infiltrate the area by Tuesday through the middle of next week.

AVIATION /00Z TAFS THROUGH 00Z SATURDAY/

Issued at 628 PM CDT Thu Jul 30 2026

Terminals KABR,KATY,KPIR,KMBG

VFR conditions will deteriorate to IFR in heavy rain and thunderstorms through tonight. Timing the slow moving storms has lower confidence but precipitation is expected to exit between 15z and 18z Friday.

ABR WATCHES/WARNINGS/ADVISORIES

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