A large thunderstorm complex rumbled through the Ohio Valley overnight, producing a very large outflow boundary that can easily be seen on visible satellite this morning, as well as on Memphis-based radar. The first image above shows the visible satellite as of about 7:30am. Note the roughly east-west cloud line across the middle of west TN and northeast AR, extending back into the Ozarks. The radar image below that is from 8:05am and shows a dark blue (with a little green) line from Milan to north of Covington to Marked Tree and on to near Searcy.
The outflow boundary is a wind shift with slightly drier and cooler air (very slightly) behind it according to weather observations on the back side of it. It is a line of convergence in the lower atmosphere so it has produced a line of clouds that can be seen on satellite and radar. The radar signature is also enhanced by dust, bugs, and other very lightweight objects that are picked up by the wind along the front/outflow.
This outflow will likely move through the metro area in the next hour or so, but other than some clouds, I expect little effect on our sensible weather (temperature, humidity) other than a temporary wind shift to the north. The outflow will likely weaken as it continues to move south, but could be enough to be the spark for isolated t'storms this afternoon, likely across north MS.
For a current looping radar view of the outflow, click "Current Radar and Satellite" on the tab above or click here.