Updated: Mon May 20 05:56:48 UTC 2019
A number of schools in OK have cancelled classes for today (Monday).
The SPC (Storm Prediction Center) has the area shaded as “High” which is not seen very often.
https://www.spc.noaa.gov/products/outlook/day1otlk.html
Very unusual step, but probably the right call under the circumstances. Some of the supercells will be moving through the OKC area in mid-to-late afternoon, about the same time kids would be getting on school buses to go home.
One of the worst school-related tornado disasters occurred in Belvidere, IL in April 1967. A powerful twister plowed into the high school as students were loading onto buses and heading home; the death toll was even higher than a school in Murphysboro, IL that devastated by the Great Tri-State Tornado in 1925: https://addins.wrex.com/blogs/weather/2011/04/remembering-the-1967-belvidere-tornado
Obviously, officials in OKC are trying to avoid a repeat of that tragedy by keeping the kids at home. However, I have not heard of other systems (outside Oklahoma City) that have closed schools for the day. I would predict that many of them will send students home at mid-day or early afternoon, before the worst of the weather arrives.