Air Pilot Breaks Speed of Sound, May be Explanation for Loud Boom

Outside of Milwaukee, a number of Wisconsinites heard a boom, and felt a shake last night.

Reports of an earthquake-like feeling were reported mostly in Dodge, Jefferson, and Waukesha County.

The National Weather Service received a number of calls explaining the phenomena. They thought it may have been a frost quake. 

"We did get those reports and we tried to put two and two together, and what it was based on what we've heard in the past; we've gotten reports of these in the winter before," said Denny Vancleve, a Meteorologist with the National Weather Service in Milwaukee.

Weather experts say a frost quake happens when water in soil freezes and expands. "The increased pressure of the expanding frozen soil suddenly being released creates the boom and the shaking," explained the weather service on their Twitter page.

"We also got confirmation from the Madison Tower that there was some military training exercises going on," said Denny Vancleve, a Meteorologist with the National Weather Service in Milwaukee.

The National Weather Service had also seen something called "chaff" on their radar. It can indicate a military plane in the area, and that seems to be the likely explanation. The Air National Guard confirms their 115th Fighter Wing out of Madison was training, and accidentally broke the speed of sound in a statement released today:

"A 115th Fighter Wing F-16 Fighting Falcon unintentionally exceeded the speed of sound during routine night training in the airspace above south central and south eastern Wisconsin Jan. 12, at approximately 8:29pm.  The jet's speed, which caused the air to compress, resulted in a sonic boom heard by numerous Wisconsin residents. The 115 FW pilots make every effort to minimize the impact of their training missions to local residents.   The 115 FW continues to train for its state and federal missions and greatly appreciates the overall support received from friends and neighbors throughout the state."

While no one was in danger, it startled a few people that heard it.

"My initial concern when I heard it was that an oil train had blown up," said Janet Mcconaughey, an Oconomowoc resident.

She said she also thought snow may have fallen off her roof or her solar panels had fallen to the ground.

"I called the neighbors on the other side and they said, 'I thought my husband slammed the door,'" said Mcconaughey.

She said her daughter had also felt and heard it a mile away.

"So then I knew it had to be something really big,"said Mcconaughey.