The high pressure ridge that has kept storms away from us will strengthen and keep the inversion (warmer air over cool air at the surface) over us producing the late night and early morning fog. The next cold front will slide into Oregon late in the week on Friday.

For the Willamette Valley :  Partly cloudy this evening and mostly cloudy at night  with more fog low 29 . Monday after AM fog, possible freezing fog, frost and clouds look for a mix of clouds and sun with some lingering afternoon fog high 44, then mostly cloudy at night with fog low 33. A  mix of clouds and sun Tuesday and Wednesday after morning fog and clouds high 46-48 partly cloudy with patchy fog at night low 33-35. Partly cloudy with a slight chance of rain Thursday and partly cloudy Thursday night high near 50 lows 37. Partly cloudy Friday through Sunday with a slight chance of rain highs 45 lows 34-38. For the Umpqua Basin the daytime temperatures will be about the same as the Willamette Valley, but the low temperatures will be in the mid 30’s.  At the coast conditions will be about five (5) degrees warmer for the daytime highs and a few degrees warmer at night.

For the Cascades:  The free air freezing level will rise to 10,000′ tonight falling too 8,000′ Monday, 6,500′ Monday night , 7,500′ Tuesday and Tuesday night, 6,500′ Wednesday, and 7,000′ at night. Thursday the snow level will be 6,000′ dropping to 4,500′ at night. The snow level will stay below pass levels Friday through Sunday with just a slight chance of rain or snow through the period.