The brutal blast of arctic air that shut down schools across Minnesota on Wednesday also gave students a good excuse to stay home — even if their school was open.

Several metro-area schools that stayed open or delayed start times saw huge drops in attendance. In St. Paul and Farmington, about half the student body showed up for classes.

The sometimes confusing patchwork of districts that remained open created fertile ground for mischievous behavior on social media.

Someone created a fake Twitter account that purported to be Bloomington Public Schools. And according to that account, classes were canceled. Bloomington schools, in fact, were open.

The unexpected tweet sent district leaders scrambling. School officials quickly reported the incident to Twitter and the account was disabled, but not before creating some confusion.

"It certainly kept us on our toes," Rick Kaufman, the district's director of community relations, said of the bogus tweets.

Troublemakers also recirculated old tweets from the Bloomington and Hopkins school districts when they canceled classes on Jan. 7 — of last year. Initially, some were duped.

Others fell for an official-looking tweet from "The Minnesota Weather Channel," a fake account that announced all schools were closing.

"It got kind of ridiculous," said Jolene Goldade, spokeswoman for Hopkins Public Schools.

Wednesday marked the first time in many years that the three large school districts in the Twin Cities didn't do the same thing when confronted with the decision to close schools due to poor weather. While St. Paul public schools remained open, Anoka-Hennepin and Minneapolis public schools were closed.

The differing approaches caused mixed reactions from parents, teachers and students.

"It was terrible," said Isaac Richert, a seventh-grader at Hopkins' West Junior High, one of the districts that decided to hold classes. "Other kids got to stay home."

One parent posted on Facebook: "Unbelievable, I'm appalled that my child attends school in this district. Mpls closed and St. Paul stays open? What sense is that? The buses have been late and kids should stand and wait? Ridiculous!"

St. Paul district officials had said they were leaving the decision up to parents and excusing absences for students who stayed home.

Michael Varnado allowed his daughter, Mayah, to stay home from Central High School in St. Paul. He said he appreciated the district's flexibility in letting parents do what they believe is best.

"How dare I tell another parent how to parent?" he asked. "I appreciate that this was considered an excused absence and that we had plenty of time to reach a decision about what to do."

St. Paul district parent Jennifer Holm said she and her two kids were happy school was in session. "We live in Minnesota. It's a cold state. We plan for this. We do what we need to to be there," she said, noting that on cold days, her son and daughter pack snowpants and other cold-weather gear.

In some of the more affluent suburban schools, attendance was down but not to the same degree that St. Paul public schools experienced.

About 10 percent of Eden Prairie Public Schools didn't show up for classes due to parental concerns about the weather, school officials said.

"We noticed a quite a few reported absences earlier in the week and it jumped way up today," said Jaclyn Swords, a spokeswoman for the district.

In South St. Paul, the district posted a note that read "Schools open Wednesday, Jan. 7 — absences excused" on its website. The district had 796 absences Wednesday out of 3,410 students, a 23 percent absence rate. Those students will need a parental note or call to be excused.

Lisa Brandecker, assistant to the superintendent, thought the attendance rate was "pretty good" given the weather. Superintendent Dave Webb decided not to call off school after watching reports from the National Weather Service and consulting with other superintendents, but parents "always have the right to keep them home" if it's too cold, Brandecker said.

For the most part, many of the suburban schools districts that stayed open Wednesday won praise from parents.

However, some were criticized for not giving enough notification or not being clear enough about their intentions.

School officials said they are working on ways to better inform parents and reduce the chance of people getting duped by social media. School officials have generally only been in the habit of notifying parents when school is closed.

And while that's worked well in the past, some districts are rethinking that strategy after social media caused confusion this year.

By late Wednesday, for instance, a fake Bloomington school district Twitter account announced Thursday is bring-your-pet-to-school day.

kim.mcguire@startribune.com • 612-673-4469

nicole.norfleet@startribune.com • 612-673-4495