Tuesday and Wednesday were cold days in Portland. Cold enough that on Tuesday morning, one reader spotted a strange ice formation. What is “hair ice”? Well, according to scientists in Germany and Switzerland, it is the product of fungus, likely Exidiopsis effusa. The formation is caused by ice filaments on rotting wood, generally on humid and below-freezing winter nights. Read more at the link in our bio. 📸: Courtesy of Rosie Platt #hairice #coldweather #wx #pacificnorthwest #pnw #oregon #portland #portlandoregon