SPOKANE, Wash. — Dense fog has rolled back into the Spokane area. Fog moved in Thursday, blotting out the sunshine that dominated much of the day. The Dense Fog Advisory remains in place through noon Friday, but we are likely not done with it as we head into the weekend.
With visibilities already down to one-quarter of a mile, it's best to treat it as if it were active now. Between 1 and 2 o'clock, the visibility in Spokane dropped from 7 miles to one-quarter of a mile. Drivers should drive with headlines on in dense fog, even during the day. Use low beams if you have them as well.
Computer models have the dense fog at it's worst and most widespread just after sunrise Friday morning. Model visibility was as low as 400 feet during this time, which is incredibly low. Friday night and Saturday morning appears to feature more thick fog for the region, so another Dense Fog Advisory may be issued.
These types of advisories are typically only issued one day at a time, so another update on the advisories will likely come down around 2 to 3pm Friday.
A saturated layer of air near the ground has been unable to dry out due to a temperature inversion in the atmosphere. This plus the melting and evaporating snow has added to the relative humidity, thus dense fog has been an issue recently and will likely be an issue through at least Saturday morning.
Drivers should drive cautiously in the night and morning hours as temperatures below freezing means that the fog is a freezing fog and can create slippery roads and bridges.