Another chilly night is in store for us here in Southern Oregon and Northern California, especially east of the Cascades. Subzero temperatures reached nearly 20 below last night in both Klamath and Lake counties and tonight they will near similar temperatures. I also came across a report of just 19 degrees in Medford, however most of the city was sitting in the low 20′s near midnight before some low lying clouds and fog developed to prevent temperatures from bottoming out further. Teens were also reported in other locations of the Rogue Valley! Tonight isn’t looking as cold, however we will still see unseasonably cold temperatures dropping into the low and mid 20′s. Frost will definitely be on your windshield in the morning and you will want to dress in layers if you’re planning on heading out this evening or early tomorrow! There are still many reports of icy patches and snow packed roads from last week’s disturbances and with any patchy freezing fog that develops this evening in the valleys- bridges, overpasses, etc. will continue to see slick spots!
With light winds and temperatures so cold overnight inversions tend to form in the valleys (especially when high pressure dominates the region), trapping cold air near the surface. This then effects our afternoon highs and makes daytime warming a little more difficult; it was also in full effect Sunday. Most locations had trouble warming out of the 30′s! With this evening expected to be extremely cold again, I believe we will see the same issue into Monday with temperatures similar to or a few degrees above Sunday’s highs. Winds will pick up a bit as we head into mid week and this will then help to break up morning fog and low lying clouds quicker-so daytime warming will be rather strong and we’ll see quite mild temperatures in the afternoons!
All week long we will have the same high pressure air mass over our region, and although this brings us sunny skies in the afternoons it will be impacting air quality. An air stagnation advisory has been issued for the Klamath Basin this evening until 4AM. Because inversions trap cold air near the surface (since there is warm air above preventing the air from rising), fumes, pollutants, dust, and grasses get trapped as well, impacting air quality. This will be a concern for the next several days and tends to occur when one air mass is over an area for an extended period of time. It is also why an air stagnation advisory has been issued!
Enjoy the nice weather and bundle up at night! Follow me on Facebook for daily weather updates and stay tuned to NewsWatch12! Thanks for logging on and have a great week!