482 ACUS11 KWNS 091901 SWOMCD SPC MCD 091901 SDZ000-092030- Mesoscale Discussion 1556 NWS Storm Prediction Center Norman OK 0201 PM CDT Thu Jul 09 2026 Areas affected...portions of the Black Hills and southwestern South Dakota Concerning...Severe potential...Watch unlikely Valid 091901Z - 092030Z Probability of Watch Issuance...20 percent SUMMARY...Isolated thunderstorms may move off the Black Hills in southwestern South Dakota and promote an isolated severe threat this afternoon. A further increase in strong to severe thunderstorm potential is expected late this afternoon and into the evening. DISCUSSION...An isolated thunderstorm has recently developed across the Black Hills in southwestern South Dakota. While latest objective analysis suggests that capping remains in place to the east of the Black Hills, modifying the nearby UNR 18z observed sounding for current surface observations suggests that inhibition is quickly eroding amid continued insolation. This may allow isolated convection to evolve eastward off of the Black Hills this afternoon. Should this scenario occur, storms would encounter increasing instability across central South Dakota, with modest effective shear (25-30 kts), well-mixed boundary layer profiles, and steep mid-level lapse rates (as sampled by the aforementioned UNR observed sounding) promoting a risk for isolated damaging/severe wind gusts and large hail. Given that this risk remains conditional on a storm persisting eastward off of the Black Hills, watch issuance is uncertain at this time. An increase in severe potential and convective coverage is then expected later this evening across portions of western South Dakota. ..Chalmers/Hart.. 07/09/2026 ...Please see www.spc.noaa.gov for graphic product... ATTN...WFO...UNR... LAT...LON 43410276 43380317 43430356 43580388 43830402 44130404 44500399 44700393 44790377 44790318 44750266 44550228 44200203 43840207 43580234 43410276 MOST PROBABLE PEAK WIND GUST...55-70 MPH MOST PROBABLE PEAK HAIL SIZE...1.00-1.75 IN  478 ACUS11 KWNS 091915 SWOMCD SPC MCD 091915 NYZ000-092115- Mesoscale Discussion 1557 NWS Storm Prediction Center Norman OK 0215 PM CDT Thu Jul 09 2026 Areas affected...Portions of western New York Concerning...Severe potential...Watch unlikely Valid 091915Z - 092115Z Probability of Watch Issuance...20 percent SUMMARY...Strong to marginally severe wind gusts are possible along and near the southern Lake Ontario shoreline. A watch is not expected given the limited spatial extent of the threat. DISCUSSION...A organized linear segment is ongoing near Toronto driven by ascent from a shortwave trough. While the airmass near the Lake Ontario shore is slightly cooler than surrounding areas, the organization of the linear segment will likely allow it to propagate some distance along the shoreline with aid from the lake breeze boundary. The spatial extent of the threat is not expected to reach farther inland than a county or two. Strong to marginally severe wind gusts, particularly along the more exposed lake shore, are possible. ..Wendt/Hart.. 07/09/2026 ...Please see www.spc.noaa.gov for graphic product... ATTN...WFO...BGM...BUF... LAT...LON 42877729 42907891 42878019 43677928 43707631 43527607 43167630 42877729 MOST PROBABLE PEAK WIND GUST...55-70 MPH