Morning Fog Season Is Here; Probably Will Be Even Foggier This Year

Satellite photo from early this morning shows webs
of fog in the river valleys of Vermont, and in much
of the Champlain Valley 

 There was lots of fog in the valleys of Vermont this morning. The National Weather Service in South Burlington even issued a special weather statement noting the fog was more widespread than usual today.  

Get used to it. 

As summer wanes and we get toward autumn morning fog will be a frequent visitor to Vermont, especially in the river valleys.

Any clear, calm night for the next several weeks will probably give us misty mornings.

The ground and water bodies have been warming up all summer. Now, on calm, clear nights, the air temperature will dip below that of the water. Moisture rising from the water will hit that cool air and condense into fog.

This happens every year, of course. Transpiration from trees contributes to it as well. So does wet ground. 

And boy, do we have wet ground!  After all those floods and storms and rainy periods we've had for months, the soil is still soggy as heck.  That will probably make us even more foggy during the early autumn, unless we see weeks of dry weather starting now. 

Spoiler: Some showers are in the forecast Tuesday and Wednesday. 

Fog will mostly be a creature of early mornings in the coming weeks. As the sun rises, it heats the air, causing it to mix around and that disperses the fog. Even the thickest fog banks near rivers usually disappears by 10 a.m. or 11 a.m. at the latest.

On some occasions, a temperature inversion will seal the moisture near the surface more efficiently. On those days, the fog might lift into a low, dreary overcast that might not break up until afternoon. That won't happen often, but it probably will occasionally. 

This morning's fog was more widespread than usual because the same temperature inversion that kept parts of Vermont overcast into Sunday afternoon continued to exist.  Since the air was already moist, it didn't take long for fog to take hold, and spread. 

The fog was burning off at midmorning and today will be a pleasant Monday.