Monday, January 18, 2010

Fog and Freezing Fog

MONDAY EVENING UPDATE:

Our stagnant pattern continues.  After a cloudy day today, more fog will be around tonight.  With temps in the upper 20s, this will create areas of freezing fog where fog persists.

SUNDAY NIGHT POST:

Another round of fog tonight and into Monday morning.  Abundant amounts of moisture are trapped in the lowest layer of the atmosphere near the surface due to warmer temperatures melting snow cover on the ground.  This additional moisture is being trapped close to the ground by a strong temperature inversion at about 1,000 ft. 

The result is dense foggy nights and mornings.  This has curved and limited high temperatures allowing them to only reach the low and middle 30s.  Dense fog and freezing fog advisories are in effect through Monday morning.  Temperatures are expected to remain below freezing allowing the water vapor from the fog  become ice on surfaces that are below freezing.  This includes untreated road surfaces and especially overpasses.  Drive carefully.