Frost Advisory issued September 14 at 4:04PM PDT until September 15 at 8:00AM PDT by NWS

...FROST AND FREEZING CONDITIONS EXPECTED EAST OF THE CASCADES TONIGHT AND FRIDAY NIGHT... .The coolest air mass this season will move into the area tonight. This along with clear skies and light winds will allow temperatures to fall to near or below freezing tonight into early Friday morning and again Friday night into early Saturday

from Current Watches, Warnings and Advisories for the United States Issued by the National Weather Service http://ift.tt/2eYelel