The cold descending across the Midlands is expected to be the worst Omaha has seen in at least four years, and maybe more than 15 years.
If the forecast holds, Omaha-area school districts will likely cancel classes Monday, even though winter break is just ending.
School officials were conferring Friday. They will watch the forecast through the weekend, and plan to decide Sunday night or Monday morning.
“It isn't a decision to be made lightly,” said Annette Eyman, spokeswoman for the Papillion-La Vista School District.
Her comments were echoed by spokeswomen at the Bellevue, Millard and Westside districts. The Omaha Public Schools has a previously scheduled day off Monday.
In Minnesota, the governor canceled Monday classes across the entire state because of forecast wind chill readings of 40 below to 60 below zero.
In the Omaha area, the National Weather Service expects wind chills of at least 20 degrees below zero from Sunday afternoon through Monday evening.
By Monday morning, wind chills could be 25 below to 40 below zero, according to the weather service.
Those wind chills would meet the standard that triggers the school-cancellation discussion underway by district officials. Eyman said Papillion-La Vista is holding off on a decision until at least Sunday night because forecasts can change.
Generally speaking, other factors that influence school-cancellation decisions: whether snow is blowing and drifting, whether roads and sidewalks are passable, and whether wind chills are expected to remain dangerously low for a prolonged period.
Parents already are assessing their options, including whether to work from home, take another vacation day or enlist the help of a grandparent, their day care or even their local YMCA.
Four years ago, the region was enduring harsher weather than has been the case this winter. During the 2009-10 winter, record snowfall in December set the stage for plunging temperatures in early January.
On Jan. 4, 2010, Omaha had 17 inches of snow on the ground, the temperature bottomed out at 20 degrees below zero and wind chills dropped to 35 degrees below zero.
The next night, the temperature again fell to double digits below zero, this time to minus-16 degrees.
Omaha has gone a longer time — 17 years — since it has had a day as cold as Monday's forecast, said Barbara Mayes, meteorologist with the National Weather Service.
Monday's high is forecast at 1 degree below zero, and the last time Omaha's daytime high failed to climb above that was Jan. 10, 1997, she said.
“The most important thing is for people to take precautions,” Mayes said.
Record temperatures are unlikely to be set by this cold spell, she added. Daily record lows for this time of year in Omaha range from 20 degrees below zero to 32 degrees below zero. Daytime records for coldest high temperature range from 5 degrees below zero to 10 degrees below zero.
Harry Hillaker, state climatologist for Iowa, said this winter feels rude because it has been colder than average and because the past several winters have been relatively mild.
Last month, temperatures averaged 5.6 degrees below normal, he said, which is a significant falling off. Iowa hasn't had a colder average month in three years — since January 2011, he said.
On the other hand, Iowa has already seen colder weather in the last few weeks than may occur this weekend. Hillaker said the low in Osceola dropped to 27 degrees below zero on Christmas Eve.