First possible fall freeze for parts of the valley

By Rod Hill on 2019-09-26

Today’s weak cold front is the first push of colder air returning to the Northwest.  A  more
impressive cool-off arrives Friday, bringing increasing showers and eventually the coldest
overnight lows and daytime highs of the early fall season. 
Assuming showers mostly end for the valley Sunday morning, Portland will dip below 50 degrees 
for the 1st time this fall season.  The air will likely be dry and cool enough to produce widespread
temperatures in the 30s Monday morning, including the possibility of frost in spotty locations, such
as Hillsboro, Battle Ground and other usual morning cold spots.  Monday and Tuesday will bring
the first realistic chance of freezing temps to the valley, although Portland will likely hold near 40 degrees. 
It all means that sensitive plants you are not ready to lose, should be protected.
Also, travelers should be alert for the first snow showers of the season at pass level, starting Friday 
overnight through Sunday.  Ground temps at pass level will likely hold above freezing during the day, 
meaning no significant icing is expected.  If the skies part, we may all be treated to a visual fresh skirt of
snow on the high country Sunday morning!
Meteorologist Rod Hill