Subj : MESO: Mesoscale Discussion 1818 To : wx-storm@lists.illinois.edu From : COD Weather Processor Date : Mon Jul 28 2025 02:48:12 ACUS11 KWNS 280248 SWOMCD SPC MCD 280247=20 IAZ000-MNZ000-SDZ000-NEZ000-280445- Mesoscale Discussion 1818 NWS Storm Prediction Center Norman OK 0947 PM CDT Sun Jul 27 2025 Areas affected...Far Southern Minnesota...Far Southeast South Dakota...Far Northern Iowa Concerning...Severe Thunderstorm Watch 548... Valid 280247Z - 280445Z The severe weather threat for Severe Thunderstorm Watch 548 continues. SUMMARY...An isolated severe threat is expected to continue into far southern Minnesota, far southeast South Dakota and northern Iowa over the next few hours. Wind damage and hail will be the primary threats. DISCUSSION...A broken line of strong to severe thunderstorms is currently ongoing from northeast South Dakota eastward across southern Minnesota. Additional storms are ongoing near a surface low in southeast South Dakota. To the east of the surface low, a moist and unstable airmass is in place, with the RAP showing MLCAPE ranging from near 5500 J/kg in southeast South Dakota to around 2500 J/kg in northeast Iowa. The instability, along with large-scale ascent associated with the right entrance region of the upper-level jet, is supporting continued convective development this evening. In addition, the latest WSR-88D VWP at Sioux Falls, South Dakota has 40 knots of 0-6 km shear, and the RAP suggests this is representative for much of the airmass to the south of the ongoing convection. This will support threat for wind damage and hail with the more intense parts of the line over the next couple hours, mainly over southeast South Dakota and southwest Minnesota were the strongest instability is present. As the convection moves southward, a gradual downtrend in the severe threat is expected due to less favorable storm modes, especially over parts of north-central and northeast Iowa where the RAP shows a less supportive shear environment. ...Broyles.. 07/28/2025 ....Please see https://urldefense.com/v3/__http://www.spc.noaa.gov__;!!DZ3fj= g!_zM1uD5K47MsfW8zgOlderxH4PkdOj-U5_O-XhHwCbdIU92JZUASxjBA9c7ofgI5rUO9dCfOM= Zk2i7PTup_iE0tN-14$ for graphic product... ATTN...WFO...DVN...ARX...MPX...DMX...FSD...OAX... LAT...LON 43029806 43589819 43989806 44379768 44449717 44269613 44159546 44109396 44319292 44209199 43849141 43439125 43059133 42699166 42499246 42489299 42499466 42589671 42779756 43029806=20 MOST PROBABLE PEAK TORNADO INTENSITY...85-115 MPH MOST PROBABLE PEAK WIND GUST...55-70 MPH MOST PROBABLE PEAK HAIL SIZE...1.00-1.75 IN =3D =3D =3D To unsubscribe from WX-STORM and you already have a login, go to https://lists.illinois.edu and use the "Unsubscribe" link. Otherwise email Chris Novy at cnovy@cox.net and ask to be removed from WX-STORM. --- SBBSecho 3.28-Linux * Origin: capitolcityonline.net * Telnet/SSH:2022/HTTP (1:2320/105) .