Subj : MESO: Mesoscale Discussion 1450 To : wx-storm@lists.illinois.edu From : COD Weather Processor Date : Thu Jun 27 2024 22:01:52 ACUS11 KWNS 272201 SWOMCD SPC MCD 272201=20 MTZ000-272330- Mesoscale Discussion 1450 NWS Storm Prediction Center Norman OK 0501 PM CDT Thu Jun 27 2024 Areas affected...Portions of southeastern Montana Concerning...Severe Thunderstorm Watch 473... Valid 272201Z - 272330Z The severe weather threat for Severe Thunderstorm Watch 473 continues. SUMMARY...The severe threat continues across Severe Thunderstorm Watch 473. Severe wind gusts (a few of which could reach 75-90 mph) are the main threat, though isolated instances of hail or even a tornado remain possible. DISCUSSION...Multicells and transient supercells are merging into a singular MCS across portions of southeastern Montana. These storms have been traversing a mixed boundary layer (characterized by 9.5 C/km 0-3 km lapse rates per 21Z mesoanalysis), with a history of producing multiple severe gusts. Preceding the upscale growing MCS=20 is a warm sector that moistens with eastward extent, with 60s F dewpoints beneath 7.5 C/km mid-level lapse rates contributing to 2000-3000 J/kg MLCAPE near the MT/ND border. Given widespread 50+ kt effective bulk shear, the MCS should at least maintain intensity through the evening. However, deep-layer shear vectors become more perpendicular to MCS orientation with eastward extent, which may promote further organization into a bow-echo MCS with increased severe gust potential. A few 75-90 mph gusts may occur near the apex of any bow echo that can form, with large hail possible with any stronger storm cores. A tornado also cannot be ruled out with any mesovortices that can become established. ...Squitieri.. 06/27/2024 ....Please see https://urldefense.com/v3/__http://www.spc.noaa.gov__;!!DZ3fj= g!_bHGsJdzBWZQDjILxDYxm7AksgjaRfaDDYgCs7GVqH5B91jpB1tp33l2NvNQ6aTL4sXelgRjx= vZDsxC46nkVGnNOL6E$ for graphic product... ATTN...WFO...BYZ...GGW... LAT...LON 45050599 47040582 47670582 48050561 48050477 47730424 47270422 45910436 45280439 45010473 45050599=20 =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 3.20-Linux * Origin: capitolcityonline.net * Telnet/SSH:2022/HTTP (1:2320/105) .