usa

An aerial view at night of the downtown Chicago skyline. An Arctic air mass is expected to chill much of the Central Plains and the East Coast through Monday with wind-chill temperatures dropping into the single digits overnight in some places.

Kiichiro Sato/AP

A nightime aerial view of downtown in the US city of Chicago

Vettori, Piano and Kovar of Italy jump to block the ball spiked by Anderson of the U.S. during their FIVB Men's Volleyball Grand Champions Cup 2013 in Tokyo...(L to R) Luca Vettori, Matteo Piano and Jiri Kovar of Italy jump to block the ball spiked by Matthew Anderson of the U.S. during their FIVB Men's Volleyball Grand Champions Cup 2013 in Tokyo November 22, 2013.

Yuya Shino/Reuters

(From left) Luca Vettori, Matteo Piano and Jiri Kovar, of the Italy men’s volleyball team, jump to block a ball during their match against the US at the FIVB Grand Champions Cup tournament in Tokyo

President Barack Obama awards former President Bill Clinton with the Presidential Medal of Freedom, Wednesday, Nov. 20, 2013, during a cermeony in the East Room of the White House in Washington.

Jacquelyn Martin/AP

President Barack Obama awards former president Bill Clinton with the presidential medal of freedom on Wednesday, during a ceremony at the White House, Washington.

.James Getty, portraying President Abraham Lincoln, stands before a ceremony commemorating the 150th anniversary of the dedication of the Soldiers  National Cemetery and President Abraham Lincoln's Gettysburg Address, Tuesday Nov. 19, 2013, in Gettysburg, Pa. Lincoln's speech was first delivered in Gettysburg nearly five months after the major battle that left tens of thousands of men wounded, dead or missing. Getty is scheduled to deliver the Gettysburg Address at Tuesday's ceremony.

Matt Rourke/AP

James Getty, portraying President Abraham Lincoln, stands before a ceremony commemorating the 150th anniversary of the dedication of the Soldiers National Cemetery and President Abraham Lincoln’s Gettysburg Address on Tuesday, in Gettysburg, Pa. Lincoln’s speech was first delivered in Gettysburg nearly five months after the major battle that left tens of thousands of men wounded, dead or missing. Getty is scheduled to deliver the Gettysburg Address at Tuesday’s ceremony.

Boston Red Sox relief pitcher Koji Uehara and catcher David Ross celebrate as Red Sox beat St. Louis Cardinals' to end a 95 year wait to clinch the World Series title at Fenway Park Stadium, Boston. The last time Red Sox won the World Series, all-time great Babe Ruth was one of their lead pitchers.

Matt Slocum / AP

Boston Red Sox relief pitcher Koji Uehara and catcher David Ross celebrate as Red Sox beat St. Louis Cardinals to end a 95 year wait to clinch the World Series title at Fenway Park Stadium, Boston.

With the BART transit system on strike, traffic slows on the Richmond-San Rafael Bridge during the morning commute Monday, Oct. 21, 2013, in San Rafael, Calif.  San Francisco Bay Area commuters started the new work week on Monday with gridlocked roadways and long lines for buses and ferries as a major transit strike entered its fourth day. At the same time, federal investigators were searching for clues to a weekend train crash that killed two workers.

Eric Risberg/AP

As the BART transit system entered its fourth day of strikes, traffic slows on the Richmond-San Rafael Bridge, as San Francisco Bay Area commuters started the new working week on Monday with gridlocked roads and long lines for buses and ferries. At the same time, federal investigators were searching for clues to a weekend train crash that killed two workers.

US Vice President Joe Biden greets Environmental Protection Agency workers with muffins as they return to work after 16 days of a government shutdown at the William Jefferson Clinton Federal Building in Washington DC.

Jacquelyn Martin / AP

Joe Biden, US vice-president, greets Environmental Protection Agency workers with muffins as they return to work after 16 days of a US government shutdown at the William Jefferson Clinton Federal Building in Washington.

Police tape blocks a closed Lincoln Memo...Police tape blocks a closed Lincoln Memorial on the National Mall October 1, 2013 in Washington, DC. The US government is in a forced shutdown after lawmakers failed to pass a spending bill last night. AFP PHOTO/Brendan SMIALOWSKIBRENDAN SMIALOWSKI/AFP/Getty Images

Brendan Smialowski/AFP/Getty

Police tape blocks a closed Lincoln Memorial on Tuesday in Washington, DC. The US government is in a forced shutdown after lawmakers failed to pass a spending bill. 

 The crew on Oracle Team USA wave after winning the 17th race of the America’s Cup sailing event against Emirates Team New Zealand in San Francisco. After staging an improbable comeback from seven points behind, Oracle Team USA have forced a winner-take-all final race for the 162 year old trophy in this 34th America’s Cup.

Ben Margot / AP

The crew on Oracle Team USA wave after winning the 17th race of the America’s Cup sailing event against Emirates Team New Zealand in San Francisco. After staging an improbable comeback from seven points behind, Oracle Team USA have forced a winner-take-all final race for the 162 year old trophy in the 34th America’s Cup.

Steam from the Verso paper mill is backlit by the light of the setting moon in this time-exposure, Friday, Sept. 20, 2013, in Bucksport, Maine. Verso makes coated papers used by publications such as catalogs and magazines.

Robert F. Bukaty/AP

Steam from the Verso paper mill is backlit by the light of the setting moon in this time-exposure on Friday in Bucksport, Maine. Verso makes coated papers used by publications such as catalogs and magazines.

The American flags surrounding the Washington Monument fly at half mast as ordered by President Barack Obama, following the fatal shootings on Monday at the Washington Naval Yard.

J.Scott Applewhite / AP

The US flags surrounding the Washington Monument fly at half mast as ordered by President Barack Obama, following the fatal shootings on Monday at the Washington Naval Yard

Floodwater shoots out of a sewer in Manitou Springs, Colorado, as storms continue over the Waldo Canyon area.

Michael Ciaglo/AP

Floodwater shoots out of a sewer in Manitou Springs, Colorado, as storms continue to hit the Waldo Canyon area of the US.

The Tribute in Light illuminates the sky in New York on the 12th anniversary of the September 11, 2001 attacks. The tribute, an art installation of the Municipal Art Society, consists of 88 searchlights placed next to the site of the World Trade Center creating two vertical columns of light.

Timothy Clary/AFP/Getty Images

The Tribute in Light illuminates the sky in New York on the 12th anniversary of the September 11 2001 attacks. The tribute, an art installation of the Municipal Art Society, consists of 88 searchlights placed next to the site of the World Trade Center, creating two vertical columns of light

A man walks through the 9/11 Empty Sky memorial at sunrise across from New York's Lower Manhattan and One World Trade Center in Liberty State Park in Jersey City, New Jersey.

Gary Hershorn/Reuters

A man walks through the 9/11 Empty Sky memorial at sunrise across from New York’s Lower Manhattan and One World Trade Center in Liberty State Park in Jersey City, New Jersey.

A girl plants some of the 3000 flags placed in memory of the lives lost in the September 11, 2001 attacks, at a park in Winnetka, Illinois

Reuters/Jim Young

A girl plants some of the 3,000 flags placed in memory of the lives lost in the September 11 2001 attacks, at a park in Winnetka, Illinois, US

US Army Private First Class Bradley Mann...US Army Private First Class Bradley Manning arrives alongside military officials at a US military court facility to hear his sentence in his trial at Fort Meade, Maryland on August 21, 2013. A sentencing decision will be announced later Wednesday. AFP PHOTO / Saul LOEBSAUL LOEB/AFP/Getty Images

Saul Loeb/AFP

Army Private First Class Bradley Manning arrives at a US military court facility to hear his sentence in his trial at Fort Meade, Maryland, on Wednesday. Manning was sentenced for 35 years for his part in the WikiLeaks affair 

Cyclists ride past the reflecting pool in front of the Lincoln Memorial in Washington...Cyclists ride past the reflecting pool in front of the Lincoln Memorial in Washington August 20, 2013. The Rev. Dr. Martin Luther King, Jr., delivered his "I have a Dream" speech on August 28, 1963 on the steps of the Lincoln Memorial during the March on Washington for Jobs and Freedom. This coming week, Washington will play host to an array of events marking the historic anniversary.  REUTERS/Kevin Lamarque

Kevin Lamarque/Reuters

Cyclists ride past the reflecting pool in front of the Lincoln Memorial in Washington The Rev. Dr. Martin Luther King, Jr., delivered his “I have a Dream” speech on August 28, 1963 on the steps of the Lincoln Memorial during the March on Washington for Jobs and Freedom. This coming week, Washington will play host to an array of events marking the historic anniversary

Dockhands at a Potomac River boathouse in Washington pull rental kayaks from river at the end of the day.

J. David Ake

Dockhands at a Potomac River boathouse in Washington pull rental kayaks from river at the end of the day.

Police officers push back a protestor on the 10 Freeway after demonstrators angry at the acquittal of George Zimmerman in the death of black teen Trayvon Martin walk onto the 10 Freeway stopping highway traffic, in Los Angeles, California

Robyn Beck/AFP/Getty Images

Police officers push back a protester on the 10 Freeway after demonstrators, angry at the acquittal of George Zimmerman, stop traffic on the highway, in Los Angeles, California

Fourth of July, US Independence Day fireworks are seen over the US Capitol and National Monument in Washington, DC on July 4, 2013.

Paul J. Richards/AFP

US Independence day fireworks are seen over the US Capitol and National Monument in Washington, DC on Thursday night