Subj : DAY2SVR: Nws Storm Predic To : All From : Mike Powell Date : Tue Jun 27 2023 15:34:00 ACUS02 KWNS 271734 SWODY2 SPC AC 271732 Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1232 PM CDT Tue Jun 27 2023 Valid 281200Z - 291200Z ....THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS OVER THE UPPER MISSISSIPPI VALLEY... ....SUMMARY... Severe storms are most likely Wednesday afternoon and evening over parts of the upper Mississippi Valley. Sporadic severe storms are also possible over the lower Mississippi Valley, and over parts of northern to central Plains ....Synopsis... An upper high will remain situated over the southern Plains, with 50 kt midlevel winds from CO into the Midwest enhancing shear. A weak surface trough will extend from near Minneapolis southwestward into the central Plains with moderate instability along that axis. A subtle disturbance aloft will round the ridge and move from MN into MI, providing a focus for severe storms. Otherwise, diurnal activity is expected from eastern WY into NE from afternoon through evening, with continued destabilization possible overnight there. Remnant MCS activity may persist into portions of the lower MS Valley from the previous nights activity, while diurnal storms develop over the KS portion of the surface trough. ....Upper MS Valley... Moderate instability will develop during the day from IA into MN and western WI with low-level shear supporting a few supercells after 21Z. Large hail will also be likely given steep lapse rates aloft and ample shear. Storms are likely to spread southeastward during the evening, with greater uncertainty regarding MCS potential overnight. A low-level warm advection zone will develop from western WI into IL late in the day and overnight as 850 mb winds veer, and this could support at least an isolated severe risk through that corridor, depending on destabilization. Damaging winds would be the primary concern overnight. ....Northern/Central Plains... A few supercells are expected to form after 21Z from southeast WY into western NE, where low-level winds will veer to easterly, supporting moisture advection. This will occur beneath 40+ kt midlevel winds, with large hail likely. Additional severe storms with hail and wind may develop even after 00Z as the low-level jet increases over the CO/NE/KS area and capping remains minimal along I-80. ....Lower MS Valley... Northerly winds east of the upper ridge along with a moist unstable air mass will conditionally support southward-moving storms. Models solutions vary as to how much activity may be ongoing Wednesday morning, but any activity that exists or develops in this north-south warm advection zone may produce damaging gusts. ...Jewell.. 06/27/2023 $$ --- SBBSecho 3.14-Linux * Origin: Ilink: CCO - capitolcityonline.net (454:1/105) .