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"Ask A Trooper" talks black ice and blow ice

by Bonnie Amistadi

“ASK A TROOPER” by Sgt. Jesse Grabow of the Minnesota State Patrol

Question: Dear protector of humanity, first of all, thank you for the awesome job you folks do. You are appreciated! I have a husband that refuses to believe there is such a thing as “black ice.” Could you clarify and hopefully make a believer out of an individual who could possibly be a crash waiting to happen? Thank you very much!

Answer: Thank you for those very kind words. I’ve been called a lot of things in this profession, but that one is a first and I truly appreciate it. I would be glad to talk about “black ice” and, as I write this (early March), I think it’s fair to say we have enough unpredictable weather that could affect our roads. Here is my best definition of black ice: “A nearly transparent film of ice on a dark surface, such as a paved road, that is difficult to see.” With my nearly 16 years of service with the Minnesota State Patrol in northern Minnesota, I can assure you that it does exist. It’s rare, because I believe almost all ice is visible due to the sheen it puts out. A person’s vision and attentiveness could be the issue, along with the sun and other visibility factors.

Another term that is used in our parts of this great state is “blow ice.” Troopers and motorists have been dealing with this for the past two days (March 5 and 6) in west central Minnesota. I would describe this as, “when the wind blows snow across the road, either warmer temperatures or vehicle tires (or both) cause it to melt and freeze quickly, becoming ice.” Just another way we get slippery roads without freezing rain.

Both issues are reminders to always pay attention. Evaluate your drive as you move along and immediately reevaluate it. Driver’s must focus and concentrate on driving. End your winter on a safe note and continue it all year long!

If you have any questions concerning traffic related laws or issues in Minnesota, send your questions to Trp. Jesse Grabow – Minnesota State Patrol at 1000 Highway 10 West, Detroit Lakes, MN 56501-2205.  (You can follow him on Twitter @MSPPIO_NW or reach him at, jesse.grabow@state.mn.us).