The previous mark was 2.14 inches on May 31, 1892. The 5.64 inches at Will Rogers Airport was the second highest precipitation total on record in May, behind only the 6.64 inches on May 8, 1993, according to the Oklahoma Climatological Survey. It is also the second highest daily precipitation total for Oklahoma City for any month. Data goes to 1890.
Besides Friday's daily record, another 1.12 inches of rain was recorded at Will Rogers World Airport after midnight.
Combined with March and April, Oklahoma City's spring total rainfall is 23.18 inches, besting the previous wettest spring mark of 20.31 inches from 1947.
“These were very slow moving,” Brown said. “The overall wind fields weren't extreme, so these big storms just kind of took over the environment.
“And they liked where they were at and they were getting the fuel that they needed so there really wasn't a whole lot of movement.”
Brown said that's a difference between these storms and those of May 20, which included an EF5 tornado. Although it was a long-track tornado May 20, those storms went ahead and moved off, he said. But, Brown added, the storms that occurred Friday “set up shop.”
Again, he said, the wind shear was “not real strong” Friday.
Wind shear is the rate at which wind velocity changes from point to point in a given direction, such as vertically, according to the National Weather Service.
“For really, really strong tornadoes the wind shear was better back on May 20,” Brown said. “There are probably several reasons, but one of the reasons we didn't have several big tornadoes like we did on May 19-20 had something to do with the amount of wind shear in the atmosphere.
“For violent and long-track type tornadoes, a delicate balance of atmospheric conditions have to be reached, which includes the wind fields and instability. Fortunately, it is rare for this balance to be reached.”
The National Weather Service will continue to gather information on Friday's storms.