PESKY FOG

This is a visible satellite shot of Arkansas and Oklahoma from 3:01 PM on Saturday. Note the little plume of clouds, jutting out from the western border of AR... this is fog, and it kept the "chill" on in the River Valley for Saturday and the early part of Sunday.

As we've blogged about before, the mountains channel draining cold air at night to the east as it flows from higher terrain into the western valley. Fort Smith has an easterly wind over 50% of the time due to this localized effect. Over most of the weekend we were advecting warm air aloft into the area which trapped the cold air in place. Fog developed and more or less stuck around for some 36 hours in places. The temperature inversion broke around noon today, allowing the fog to "burn off" and sunshine finally graced the River Valley once again to make for a pleasant afternoon.

Posted by Ted Zarras at 7:22 PM