Mesoscale Discussion 1873
Issued: · Valid: –
Summary
Developing thunderstorms in southern North Dakota, northeast South Dakota, and far western Minnesota may intensify tonight, potentially bringing severe wind gusts and large hail. There is a possibility of severe weather watches being issued as these storms grow over the next few hours.
Product Text
000 ACUS11 KWNS 090348 SWOMCD SPC MCD 090347 MNZ000-SDZ000-NDZ000-090545- Mesoscale Discussion 1873 NWS Storm Prediction Center Norman OK 1047 PM CDT Sat Aug 08 2026 Areas affected...Southern North Dakota into northeast South Dakota and far western Minnesota Concerning...Severe potential...Watch possible Valid 090347Z - 090545Z Probability of Watch Issuance...40 percent SUMMARY...Elevated thunderstorms developing along the North Dakota/South Dakota border may continue to intensify and grow upscale over the coming hours. If upscale growth can occur, a more pronounced severe risk may emerge and require watch issuance. Convective trends are being monitored. DISCUSSION...Deep convection has begun to emerge along the ND/SD border over the past 30-45 minutes with additional towering, but weaker, convection noted in GOES IR imagery over southern and eastern ND. Similar to previous attempts at sustained deep convection, this activity appears to largely be driven by increasing isentropic ascent within the warm advection branch of a weak cyclone over the western Dakotas - augmented by a slight uptick in the nocturnal jet strength over the past hour (per regional VWPs). This emerging convection resides on the northern periphery of a buoyancy reservoir with MUCAPE values as high as 4000 J/kg analyzed downstream into SD. Additionally, 50-60 knot effective bulk shear was recently sampled by the 00 UTC BIS and ABR RAOBs, suggesting that intensification/organization of this convection is likely. Given the trends in IR imagery, adequate forcing for ascent, and downstream environment, it appears possible that some severe threat will emerge over the next few hours along the ND/SD border. Latest runs of the RRFS appear to be capturing convective trends well and suggest additional convection will manifest over the next 1-2 hours before growing upscale. If/when this occurs, the potential for severe hail and severe wind gusts will likely increase. Convective trends are being monitored, and watch issuance may be required if convective coverage increases. ..Moore/Mosier.. 08/09/2026 ...Please see www.spc.noaa.gov for graphic product... ATTN...WFO...MPX...FGF...FSD...ABR...BIS... LAT...LON 44089833 45710129 46190136 46520111 46710048 46269615 45709598 45139615 44619650 44369697 44169761 44089833 MOST PROBABLE PEAK WIND GUST...55-70 MPH MOST PROBABLE PEAK HAIL SIZE...1.50-2.50 IN