Early in the afternoon on May 20, 2013 all of the needed ingredients for severe thunderstorms, and tornadoes were in place. An unstable air mass was present thanks to values of CAPE (Convective available potential energy) that ranged from 3500 - 5000 J/kg, high temperatures that were in the low to mid 80's °F (27 °C to 30 °C) , high dew point temperatures that were in the upper 60's to lower 70's °F (20 to 22 °C), and wind shear speeds ranging from 40 to 50 knots. All of these factors were further enhanced by the fact that the southern plains were just ahead of a cold front, and were near the outflow from the convection of the storms that happened the day before, and early morning storms further east. As a result, these factors helped to enhance the storms intensity and the structure needed for a tornado to develop.
This was exactly the case on May 20, 2013.
At 2:56 p.m. CDT, to the horror of Moore, Oklahoma residents, an EF-5 tornado had developed NW of Newcastle Oklahoma, (SW of Moore), and moved northeastward right through the city of Moore. This tornado destroyed approximately 1,150 houses, inflicted 212 injuries, and claimed 24 lives, and was the deadliest Tornado since the May 22, 2011 Joplin Tornado.
Two public schools ( Briarwood Elementary, and the Plaza Towers Elementary School) sustained some of the worst destruction, where tragically 7 students died at the Plaza Towers Elementary School.
May 20, 2013 will never be forgotten by Moore residents, as this tragedy has left a devastating reminder of what mother nature can do.