PHILADELPHIA (CBS) — Hurricane-force wind gusts, torrential downpours, continuous lightning and multiple tornadoes. This is the summer of the severe storm in the Delaware Valley.
The National Weather Service has issued 279 severe thunderstorm warnings, more than double last year’s total, and 29 tornado warnings — nearly triple the number in 2018.
So will the rest of the season continue on this stormy trend?
First, we’ll look at severe weather climatology.
This shows the height of our severe weather season runs from mid-June through mid- to late July.
By mid-August, our probability of severe storm occurrence dramatically decreases.
Based on climatology, the Delaware Valley should expect fewer storms going forward.
However, due to the influence of climate change, the main ingredients for thunderstorms formation, moisture and instability are more abundantly available more often.
“In a warming environment, in this case, human-induced warming — as it’s warmer there’s more evaporation into the atmosphere,” Climate Central meteorologist Sean Sublette said, “that also means there’s more energy available for thunderstorms. Basically, there’s more fuel for the thunderstorm the warmer it gets.”
And the increase in the moisture in exponential.
“In those heaviest events, the precipitation is getting heavier,” Sublette said.
So an event like Monday’s may become more common in the future.
“We had very intense heat and humidity like we had over the weekend and into Monday,” Sublette said. “That is going to give you more energy for storms, but also the potential for some of these down bursts. There are more chances for those to cause damage as well.”