Oh sure, with this deep a snow pack, clear skies and light winds valley floor could get to 0F or lower just by radiational cooling. Friday morning (April 21 12UTC) the surface temperature on RAOB was 9C lower than 950 mb temperature. April 26, 2013 Airport low +7F and Goldstream Creek +2F with the nose of the inversion on the 12Z RAOB at 460 ft AGL and temps in the lower 20s (F).
Anything that happens n times can happen n + 1 times
Especially in the world of weather…
Oh sure, with this deep a snow pack, clear skies and light winds valley floor could get to 0F or lower just by radiational cooling. Friday morning (April 21 12UTC) the surface temperature on RAOB was 9C lower than 950 mb temperature. April 26, 2013 Airport low +7F and Goldstream Creek +2F with the nose of the inversion on the 12Z RAOB at 460 ft AGL and temps in the lower 20s (F).