The National Weather Service [NWS] has preliminary confirmation of nine tornadoes in Central Illinois on Wednesday and Thursday of last week.
“Scattered supercell thunderstorms initially developed west of the I-55 corridor along a pre-frontal trough during the afternoon,” said the NWS. “One of these storms produced a tornado that impacted portions of Woodford and Marshall Counties and dropped golf ball-sized hail [1.75" diameter].”
Wind gusts ranged from 60-70 mph across the region.
The NWS said contributing factors on June 11 included “a warm and very humid airmass across Central Illinois with temperatures well into the 80s and dewpoints in the middle to upper 70s.”
That was followed by a cold front that stretched from western Wisconsin southwestward to near Kansas City.
The list includes what the NWS called “the high-end EF3 Washburn” tornado early Thursday evening. An EF1 twister tracked through Morton. An EF0 tornado touched down in McLean County southeast of Saybrook before tracking onward toward Gibson City. An EF1 touched down north of Paxton.
Tornadoes are rated on an EF0 to EF5 scale. EF5 is the strongest.
The weather service rated seven of the tornadoes EF1 in strength. One was an EF0 and one was an EF1. That summary does not include heavy damage in Streator. The service said on its website further updates are possible.