Freezing temperatures Tuesday night might have caused something called a "frostquake" in southern Wisconsin, according to the National Weather Service in Sullivan. 
 
 Though frostquake is a geological rather than a meteorological term the boom felt in an area from about Columbus to Fox Lake and Johnson Creek to Oconomowoc prompted some people to call the weather service to report the event, meteorologist Justin Schultz said. 
 
 "It would sound like someone drove into your house, but as far as we know it didn't cause any damage," Schultz said. 
 
 Can confirm the frostquake. It shook the house here in Beaver Dam. @madisontraffic @NWSMKX — Bob Lesh (@Bob_Lesh) January 13, 2016 
 
 According to Schultz, the phenomenon occurs when water that drains into the ground freezes, expands and places stress on the surrounding ground. 
 
 "The fracturing of the soil and rock creates the frostquake," Schultz said of the seismic event that is actually called a cryoseism. 
 
 "This one was maybe a brief rumbling, but a very loud boom was the primary characteristic of this frostquake." 
 
 Frostquakes are relatively rare events, Schultz said, but not unheard of in Wisconsin. 
 
 "Of all the states that have reported cryoseisms, Wisconsin is among them," Schultz said. ||||| Rare and violent autumn storms ripped across Illinois on Sunday, spinning off tornadoes before slamming into Chicago with punishing rain and wind.As heavy gusts toppled trees and power lines and downpours swamped city streets, tens of thousands of Bears fans were evacuated from their Soldier Field seats and forced to take cover inside or huddle behind the historic stone colonnades.Earlier, in southern Illinois, severe weather decimated farms, killing at least five people, including an elderly brother and sister, when a tornado barreled through their house. Farther north, near Peoria, a tornado flattened large swaths of Washington, killing at least one person and sending about 50 others to local hospitals.As night fell and temperatures dropped, emergency workers were still searching debris fields that had once been neighborhoods and the homeless were seeking temporary shelter.Meteorologists had predicted the violent storms days ahead of time, anticipating volatile atmospheric conditions that are freakish for a season when tornadoes are a relative rarity. “Weather doesn't get more extreme than this in Illinois very often,” said Matt Friedlein, a National Weather Service meteorologist.The storms exploded over Illinois when gusting winter jet streams from the northwest collided with the unusually warm and moist air that had arrived Saturday.“You've got wintertime winds in the atmosphere above summertime moisture,” Friedlein said. “While unusual, when that happens, you're going to have very strong storms that move very quickly.”At Soldier Field, Bears fans scattered for cover under roiling skies as the game was postponed because of the threat of lightning. Though rains and high winds battered the city, temporarily closing some streets, officials received no reports of weather-related injuries, said Melissa Stratton, spokeswoman with the Chicago Office of Emergency Management and Communications.As of Sunday evening, crews were working to clear streets, removing some 170 tree branches or fallen trees and clearing out about 40 flooded viaducts. The Department of Water Management also received 27 calls of flooded basements, Stratton said.Across Cook County, officials were reporting relatively minor damage. Sophia Ansari, Cook County Sheriff's Office spokeswoman, said a motorist was stuck under 4 feet of water in Palos Township, near Orland Park. No injuries had been reported as of Sunday evening, Ansari said.In Lake County, trees and power lines were down, and some traffic signals were damaged, said an official with the Lake County Sheriff's Office.Will County officials, meanwhile, said homes were damaged and there were reports of a tornado touchdown in Diamond near Interstate 55. The storm caused “significant property damage” to a local bar and a nearby church.Charles Pelkie, information officer for the Will County Emergency Management Agency, said some people were temporarily trapped in the church. But they were quickly rescued, and none had significant injuries, he said.“I-55 was a mess,” Pelkie said. “There were wires down — trees, debris blocking the road.”In Grundy County, a powerful tornado touched down in Coal City with possible wind speeds of 111 to 135 mph, the National Weather Service confirmed.Washington and Pekin, communities about 20 miles apart, near Peoria, appeared to sustain the worst tornado damage in central Illinois. Whole blocks were leveled in Washington, prompting the Illinois National Guard to send a 10-person firefighting and search and rescue team, and officials were still trying to determine the extent of injuries Sunday evening.“I was hiding in the bathroom with pillows over my head,” said Karla Riter, who lives in Sunnydale Estates in the city. “When I opened the door, my roof was gone.”The Illinois Emergency Management Agency confirmed that at least one person had died in the area. No other details were immediately available.Kristen Johnson, a spokeswoman for St. Francis Medical Center in Peoria, said the hospital had treated victims with head injuries, broken bones, cuts and bruises. Eight went to the trauma unit, though two had since been moved and their status was unknown.“We anticipate the worst is over,” Johnson said.Sara Sparkman, a spokeswoman with the Tazewell County Emergency Management Agency, credited the county's early warning system for reducing the toll. “We hope that contributed to the low injuries that we are having,” she said.In southern Illinois, a tornado ravaged Washington County about 12:30 p.m., obliterating farms and livestock and killing Joseph Hoy, 80, and his sister Frances Hoy, 78, Washington County Coroner Mark Styninger said.Joseph Hoy's body was found in a field about 100 yards east of his farmhouse. His sister's body was found inside the home beneath debris, he said.“(Joseph Hoy's) house was blown away by a tornado,” said Styninger, who knew the siblings personally. “They were just very nice people.”Tribune reporters Bonnie Miller Rubin, Michelle Manchir, Geoff Ziezulewicz, Joseph Ryan, George Knue and Cynthia Dizikes contributed. 
 
 chicagobreaking@tribune.com | Twitter: @ChicagoBreaking ||||| (CNN) A massive "bombogenesis" -- an area of rapidly declining low pressure -- will wreak havoc on the Northeast this week, threatening hurricane-force winter wind gusts and blinding snow. 
 
 The bombogenesis will result in what's known as a "bomb cyclone." And the bomb cyclone, expected to strike Thursday, will likely dump 6 to 12 inches of snow in New England and hurl 40- to 60-mph gusts. 
 
 People try to keep warm in New York's Times Square on December 27. 
 
 People try to keep warm in New York's Times Square on December 27. 
 
 Two women take a selfie in front of a partially frozen fountain in New York City on Wednesday, December 27. 
 
 Two women take a selfie in front of a partially frozen fountain in New York City on Wednesday, December 27. 
 
 Karlee Winter and her brother Samuel Espinoza shovel snow from their neighbor's sidewalk in Dubuque, Iowa, on December 28. 
 
 Karlee Winter and her brother Samuel Espinoza shovel snow from their neighbor's sidewalk in Dubuque, Iowa, on December 28. 
 
 A man digs his car out in his driveway in Erie, Pennsylvania, on December 29. 
 
 A man digs his car out in his driveway in Erie, Pennsylvania, on December 29. 
 
 Jose Nieto uses a leaf blower to clear snow from the steps of a sick neighbor's house in Bloomington, Illinois, on December 29. 
 
 Jose Nieto uses a leaf blower to clear snow from the steps of a sick neighbor's house in Bloomington, Illinois, on December 29. 
 
 A man in Erie, Pennsylvania, walks with his groceries in a cart on December 29. 
 
 A man in Erie, Pennsylvania, walks with his groceries in a cart on December 29. 
 
 The Cloud Gate sculpture is blanketed with snow in Chicago's Millennium Park on December 31. 
 
 The Cloud Gate sculpture is blanketed with snow in Chicago's Millennium Park on December 31. 
 
 Two photographers are silhouetted against the frozen surface of the Reflecting Pool in Washington as they capture the first sunrise of the new year. 
 
 Two photographers are silhouetted against the frozen surface of the Reflecting Pool in Washington as they capture the first sunrise of the new year. 
 
 A barge cuts through ice on the Ohio River as it passes under the West End Bridge, along the North Shore district in Pittsburgh on January 1. 
 
 A barge cuts through ice on the Ohio River as it passes under the West End Bridge, along the North Shore district in Pittsburgh on January 1. 
 
 Firefighter Bobby Lehman, with his helmet and gear caked in ice, tries to thaw out after battling a fire in Nahant, Masschusetts, on Monday, January 1. 
 
 Firefighter Bobby Lehman, with his helmet and gear caked in ice, tries to thaw out after battling a fire in Nahant, Masschusetts, on Monday, January 1. 
 
 Icicles form on a outdoor string of lights in Houston on January 2. 
 
 Icicles form on a outdoor string of lights in Houston on January 2. 
 
 A woman in Chicago walks to work in sub-zero temperatures on Tuesday, January 2. 
 
 A woman in Chicago walks to work in sub-zero temperatures on Tuesday, January 2. 
 
 A light layer of snow dusts oak trees and Spanish moss in Savannah, Georgia, on January 3. 
 
 A light layer of snow dusts oak trees and Spanish moss in Savannah, Georgia, on January 3. 
 
 A check-in area stands empty at Boston's Logan International Airport on January 3. Thousands of flights have been canceled across the country. 
 
 A check-in area stands empty at Boston's Logan International Airport on January 3. Thousands of flights have been canceled across the country. 
 
 A New Jersey State Police boat maneuvers through ice on the Delaware River on January 3. 
 
 A New Jersey State Police boat maneuvers through ice on the Delaware River on January 3. 
 
 A tree and rowhouse are partially covered by ice after a water main break in Catonsville, Maryland, on January 3. 
 
 A tree and rowhouse are partially covered by ice after a water main break in Catonsville, Maryland, on January 3. 
 
 Omar Elkhalidi scrapes ice off his windshield in Savannah, Georgia, on January 3. Few motorists ventured out in freezing rain that coated bridges and ramps with ice, forcing police to close roads and highways. 
 
 Omar Elkhalidi scrapes ice off his windshield in Savannah, Georgia, on January 3. Few motorists ventured out in freezing rain that coated bridges and ramps with ice, forcing police to close roads and highways. 
 
 A man walks through the streets of Boston as snow begins on January 4. The brutal cold comes after a "bomb cyclone" dumped more than a foot of snow across eight states. 
 
 A man walks through the streets of Boston as snow begins on January 4. The brutal cold comes after a "bomb cyclone" dumped more than a foot of snow across eight states. 
 
 Rebecca Hollis drags her suitcases through New York's Times Square on January 4. 
 
 Rebecca Hollis drags her suitcases through New York's Times Square on January 4. 
 
 A thin layer of ice covers ornamental plants on January 4 in Plant City, Florida. Temperatures in central Florida dipped to below freezing. Growers spray water on the plants to help protect them from extreme cold. 
 
 A thin layer of ice covers ornamental plants on January 4 in Plant City, Florida. Temperatures in central Florida dipped to below freezing. Growers spray water on the plants to help protect them from extreme cold. 
 
 Workers on January 4 place sandbags in front of the Aquarium subway station to protect against flooding from Boston Harbor in Boston. 
 
 Workers on January 4 place sandbags in front of the Aquarium subway station to protect against flooding from Boston Harbor in Boston. 
 
 A jogger is bundled up against the cold near the Chicago River on Thursday, January 4, in Chicago. 
 
 A jogger is bundled up against the cold near the Chicago River on Thursday, January 4, in Chicago. 
 
 Mollie Lane carries a shovelful of snow down a street while digging her car out in Boston on January 5. 
 
 Mollie Lane carries a shovelful of snow down a street while digging her car out in Boston on January 5. 
 
 Apartment buildings in New York City poke out from the snow on January 5. 
 
 Apartment buildings in New York City poke out from the snow on January 5. 
 
 A pedestrian walks by a statue of George Washington in Boston's Public Garden on Friday, January 5, the morning after a massive storm. Blasts of arctic air have brought weather-related deaths, record low temperatures and historic amounts of snowfall to parts of the United States. 
 
 A pedestrian walks by a statue of George Washington in Boston's Public Garden on Friday, January 5, the morning after a massive storm. Blasts of arctic air have brought weather-related deaths, record low temperatures and historic amounts of snowfall to parts of the United States. 
 
 By the end of this week, parts of the Northeast will be colder than Mars. 
 
 The impending storm led to more than 2,700 preemptive US flight cancellations for Thursday, according to Flightaware.com. 
 
 At Mount Washington Observatory in New Hampshire, the temperature will plunge to minus 35 degrees Friday night into Saturday, weather observer Taylor Regan said. At last check several days ago, the high temperature on Mars was minus 2 degrees Fahrenheit. 
 
 But it's not just New England suffering winter's wrath. Freezing rain, sleet and snow are smothering parts of the Southeast on Wednesday. For some in the South, the sight of snow was a first 
 
 Deep freeze across South Carolina 
 
 Record snowfall left the Palmetto State's signature palm plants covered in white stuff. By Wednesday afternoon, some areas had seen five to six inches of snow. 
 
 A picturesque scene Wednesday in Charleston, South Carolina. 
 
 More than 13,000 tons of salt have been scattered across the state, Gov. Henry McMaster said. 
 
 Steady snowfall blanketed Charleston in snow and ice, transforming a city that rarely sees snow into a winter wonderland. If Charleston gets four inches of snow on Wednesday as predicted, it would be the most in one day since 1989, CNN meteorologist Brandon Miller said. 
 
 The Quadriga sculpture at Belmond Charleston Place gets a makeover. 
 
 Amid the Instagram-worthy scenes, McMaster warned of dangerous conditions as evening temperatures were expected to remain below freezing through Monday. Runways at Charleston International Airport closed and the South Carolina Highway Patrol reported dozens of accidents as snow and sleet fell. 
 
 McMaster urged people to stay indoors as much as possible to minimize risk of injury. 
 
 A metal pineapple tops a fountain in Charleston. 
 
 State of emergency in Georgia 
 
 In Georgia, Gov. Nathan Deal issued a state of emergency for 28 coastal counties ahead of Wednesday's storm. 
 
 Forsyth Park in Savannah, Georgia. 
 
 Savannah/Hilton Head International Airport -- typically booming with tourists this time of year -- closed " due to severe winter weather conditions ," the airport said. 
 
 In Savannah, layers of snow covered live oak trees and Spanish moss. 
 
 The bitter conditions extended through the state. In the south-central city of Tifton, Matthew Stuart Reid shot drone footage of the snowfall, set to the music of "Winter Wonderland." 
 
 Florida gets walloped with snow 
 
 From Maine to Florida, every East Coast state has at least one weather advisory, winter storm watch, winter storm warning or blizzard warning. That's 1,500 miles of severe weather alerts. 
 
 In Tallahassee, Florida, Ernst Beliard said he's never seen snow in his 21 years there. Indeed, Tallahassee had not seen measurable snowfall since 1989, CNN meteorologist Michael Guy said. 
 
 YO ITS ACTUALLY SNOWING IN TALLAHASSEE pic.twitter.com/Ydh9pc4QPG — Big Ern (@ernstnation) January 3, 2018 
 
 Deadly freeze 
 
 At least 12 people in the US have died this week in cold-related deaths, officials said. 
 
 Six deaths were reported in Wisconsin, four in Texas, one in North Dakota and one in Missouri. 
 
 The Texas deaths included two homeless people in Houston who were exposed to freezing conditions, Houston Police Chief Art Acevedo tweeted 
 
 Bone-chilling cold, intense snow in Northeast 
 
 The bombogenesis will usher in another round of single-digit or sub-zero temperatures to the Northeast. New York City hasn't warmed up above freezing since Christmas -- and the deep freeze will just get worse as snow approaches. 
 
 New York City and Philadelphia will dip to 3 degrees this weekend, Miller said. Boston will plunge to minus 7. 
 
 With 4-6 inches of snowfall expected in New York, sanitation workers are getting ready to deploy 2,200 plows to help clear the streets. That snow, combined with "exceptionally strong winds," means crews will be working in near-whiteout conditions, New York City Sanitation Commissioner Kathryn Garcia said. 
 
 New York City schools will be closed Thursday due to the impending snowstorm, Mayor Bill de Blasio said. In Connecticut, where the storm is expected to hit after midnight, Gov. Dan Malloy urged motorists to stay off the roads if possible. 
 
 In Massachusetts, snow is expected to fall at a rate of 1-2 inches per hour starting early Thursday, Gov. Charlie Baker said. About 12 inches of snow are expected in Boston, as well as the eastern and central parts of the state. The greatest concern is along the Plymouth County coast and the area from Sandwich to Dennis on Cape Cod. 
 
 In southeast Massachusetts, the day may start with freezing rain on the Cape and the islands, Baker said. By midday, a dip in temperatures may bring snow, high winds and possible flooding from "astronomically high tide," Baker said. 
 
 Some of the cities breaking record-high temps include Los Angeles (85 degrees last Friday) and Fort Collins, Colorado (68 degrees last Friday).
– A weather event that a National Weather Service meteorologist says "[sounds] like someone drove into your house" likely took place in southern Wisconsin on Tuesday night, and it wasn't a tornado, lightning strike, or earthquake. Instead, it was what's called a "frostquake," the Milwaukee Journal Sentinel reports, a rare happening in the Badger State that takes place when water that seeps into the ground freezes and expands, fracturing the ground around it. Although no damage has been called in from the so-called cryoseism, that didn't stop the extreme-weather occurrence from frightening locals. "[Loud] boom and house rumbling at 8:30 here outside of Beaver Dam WI. Crazy. Kids were scared," one resident tweeted. One other possibility for those who heard noises: "[Booms] could have been from Air Force planes on exercise per media," tweeted NWS Milwaukee. (Meanwhile, here's what El Niño has in store for the rest of us this winter.)