UPDATE:

The National Weather Service in Paducah posted this message on Facebook at 1:00 a.m. this morning:

“What we believe was chaff, released by aircraft this afternoon, has been showing up on radar for the past 10 hours now. It originated south of Olney, IL at 2:50 PM and now is 150 miles southeast entering far north Tennessee.” Advertisement

ORIGINAL POST:

The National Weather Service in Paducah sent out this Tweet at 8:52 p.m. tonight:

“We are still trying to figure out exactly what is showing up on radar tonight. Been going strong for 5 hrs now. If anyone in the Owensboro or Madisonville areas notices anything overhead or falling into their yards within next 30 min, please let us know. It is not precipitation.”

This tweet caused trained and amateur meteorologists and storm chasers to take to Twitter offering suggestions of what might be causing the 50.2 mile long stream to show up on radar. Various theories have been shared including everything from a flock of birds to an explosion in space.

Approximately 20 minutes after their first tweet, the NWS tweeted the following:

“The leading theory is chaff that originated in far southern Richland County IL around 2:50 PM this afternoon.”

According to Chris Conley, local storm chaser for news and weather stations in Owensboro, as well as Paducah and St. Louis, while the chaff idea is a theory, experts are still trying to make sense of it all.

“We don’t know what it is. It’s not showing up as a solid,” Conley said. “The whole chaff thing doesn’t make any sense. Why would they dump chaff over southern Illinois?”

According to the NWS, “chaff is a radar countermeasure used by military aircraft consisting of very small pieces of metal such as aluminum. It can appear as narrow bands of reflectivity on the radar since they are dispersed by planes flying at high speeds along a path.”

Conley said, although there is Scott Air Force Base to consider, with a chaff release there would be aluminum strips falling from the sky, because aluminum is so light.

At this point, the NWS is still working to determine what could remain in the air that long and for that distance.