My station made it all the way to 54 today. Not exactly sure how accurate it is, but the when it picked up 54, the views outside were an entirely different level. Trees severely bending, windows rattling, random things flying across my yard. It was crazy. My guess is the sleet that you saw was the same graupel that I saw. I had temps in the 40s as well. Graupel makes sense with the lower levels of the atmosphere being so unstable today. Wind still howling out there. Gusts getting up into the low 40s still. .