Frost/Freeze in Foothills of the Northern Blue Mountains of Oregon, Oregon

The mesonet station EW1881 Pendleton reported temperatures at or below freezing between 0215 to 0716. The mesonet station EW6266 Helix reported temperatures at or below freezing between 0245 to 0630. Several other stations reported temperatures at or below freezing for several hours the morning of the 23rd.

Clear skies in combination with dry flow regimes aloft resulted in good radiative cooling taking place at the surface. Temperatures in the morning had drop to or below freezing for several lower elevation locations between April 22nd to the 23rd.