(CNN) It's so cold, parts of Niagara Falls are frozen.

The winter storm that has blanketed the Midwest in snow and turned the Northeast into a deep freezer has now brought the falls' rushing waters to a halt in places.

Instagram user Inge Groot said she saw the sun come out for only 15 minutes.

Visitors to Niagara Falls snapped pictures of the majestic sights and still waters Sunday.

Emma Grafham told CNN she felt like she was in "Elsa's castle."

Emma Grafham told CNN she felt like she was in "Elsa's castle."

"There was even this set of stairs that were placed just outside the look-on spot and they had so much ice on them, it looked like Elsa had just cast her arm out and summoned up some stairs like she does in the movie," she said.

Bone-chilling cold is expected to continue in parts of the Northeast this week.

New Englanders could wake up Tuesday to temperatures that feel as cold as five to 20 degrees below zero, and many parts of the Northeast will remain under wind chill advisories through Wednesday morning.

Another cold snap will move in during the weekend, CNN meteorologist Michael Guy said.

"The waves of cold air will continue for the next two weeks," he said.