After multiple misfires this spring, the atmospheric severe weather engine began firing on all cylinders this past weekend and reached full speed Monday over Oklahoma.
The atmosphere behaved like a giant pressure cooker Monday, containing most thunderstorms until the middle of the afternoon, when the lid came off.
Thunderstorms can form as part of the atmospheric process of uneven heating in the atmosphere, known as convection. The storms are given extra vigor when temperatures, humidity and winds are within a certain range near the ground and high above.
One of the parameters meteorologists use to measure this is called convective available potential energy, or simply CAPE.
According to Mike Smith, Chief Innovation Executive of AccuWeather.com Enterprise Solutions, "The CAPE values for Monday were more than double that of what we typically see in severe weather situations."
The combination of increasing warmth and humidity near the ground, combined with a wedge of cooler, drier air moving in overhead with a strong river of wind high above allowed the storms to rapidly ignite, rotate and begin producing tornadoes.
According to Severe Weather Expert Henry Margusity, "The most violent of the storms Monday were the first few, which took full advantage of the energy stored up in the atmosphere."
This storm system that emerged over the past weekend and continued during this week was the first time this spring when all the right ingredients fell into place in the right order.
"We have had other situations this spring where the atmosphere got the cart before the horse, where chilly air blasted quickly along at the surface instead of higher up in the atmosphere," Margusity said," This led to incidents of elevated thunderstorms that produced hail rather than tornadoes and high wind gusts."
The Moore Tornado has originally been rated as EF-4 strength, by National Weather Service storm survey crews.
As far as the survivability of the Moore Tornado was concerned, Smith stated that there are almost no basements in central Oklahoma.
"When you have a tornado as strong as the Moore Tornado, a closet or bathtub is not enough protection," Smith said, "About the only way to guarantee survival of such a storm is underground or in a reinforced above-ground safe room."