A very pronounced dry line has set up along the southern plains this Wednesday evening causing a number of long sustaining super cells containing tornadoes.  So what is a Dry line??  Think of a dry line as a front, but solely a change in moisture not temperature.  First Check out the current dew point map(dew point=measurement of moisture) below.  Notice the dry line set up along western Texas through western Kansas.  Dew points east of the dry line are as high as 65, and 20 miles just to the west we have dew points in the 20′s. 

Combining the dry line with favorable shear values….about 5 discrete super cells have developed, each with a history of tornadoes.

Lets take a closer look at the farthest north storm to the west of Dodge City Kansas.  This is a good opportunity to explain storm velocity radar images.  When we’ve seen rotating storms here, we may have switched the radar over to velocity mode.  When we do this we are looking for rotation with in the storm.  What we are looking for is a defined area in the storm where winds are moving in opposite directions.  To the right we have a classic case, hence a TORNADO.  The circled area is the location of concern.  Orange colors are moving toward the radar site in Dodge City, while green shades are moving away from the radar.  Notice the small area where the two colors line up against each other,  there is our potential tornado. 

Meteorologist Brian Niznansky

Posted under Severe Weather, Storms