If anyone's interested in some historical weather, this book has some interesting details about the winter of 1846/1847 at Amity, OR. Apparently flooding rains happened from Nov 20th to Dec 20th, with snow starting around Christmas until it got 20 inches deep, and lasted until March. It starts around Page 28.
https://www.google.com/url?sa=t&source=web&rct=j&opi=89978449&url=https://greg.bennette.org/freebooks/Reminiscences%20of%20Abraham%20Henry%20Garrison.pdf&ved=2ahUKEwjvkvab7JqHAxUjxuYEHXgCAxYQFnoECBIQAQ&usg=AOvVaw0jvlhPTySOz6XYZKc2rkZX