Morning fog continues day after day in the Central Valley. For the most part, each day is slightly less humid resulting in slightly less dense fog.
In Fresno, Sunday was one of the clearest days we’ve seen in some time with light morning fog. This allows for more warming during the day but also more rapid cooling at night. The expectation is that fog will be lighter Monday morning but there is one tricky factor to consider in this situation. The absence of cloud cover and fog allows greater nighttime cooling. If we cool any more than expected, we reach the point where fog thickens quickly! Tricky, isn’t it?
I accounted for this in predicting an overnight low of 46 degrees in Fresno, but there are a number of factors in play.
A Dense Fog Advisory is in effect for most of the San Joaquin Valley from 11 PM Sunday until 10 AM Monday morning. A Dense Fog Advisory means that visibilities will frequently be reduced to less than one quarter of a mile. If driving, slow down, use low beam headlights, and keep plenty of distance between your vehicle and the vehicle in front of you. Highways affected include, but are not limited to Highway 99, Highway 41, Highway 43, Highway 180, Highway 152, and Highway 198 from Lemoore to Visalia.
Less fog and clearer skies allowed for a warmer day in Fresno Sunday.