I watched last year the Red Tailed Hawks on a college campus, can't remember which one. It snowed on them too and I wrote to the people wondering if those poor little eggs would freeze. They reassured me that these were experienced parents and would be able to care for these young despite the snow. And they were right. All three chicks hatched and fledged.
I just loved it when the parent would come back with squirrel vitals and line the chicks up and feed them one by one. It was like she was telling them: Line up, put your wings back and get ready for squirrel dinner. In no time there was nothing left of that hapless squirrel, not even a bone.
I've sure got extra squirrels this year. No winter and 7 of them are raiding my bird feeders. A friend said to put a slinky on the feeder. I'll have to move the ones hanging from the trees, but I'm going to try it.