Tuesday night's severe storms

By Grant Dade - bio - email

A line of severe Thunderstorms raced across East Texas Tuesday night and into Wednesday morning bringing strong winds, hail, and even an EF-1 tornado which touched down in Northwestern Smith County and traveled along the ground for 6.8 miles into Southern Wood County.  This tornado was formed from a phenomenon we call a "bookend vortex."  If you look at the short radar loop(shown to the right) of the storms as they moved through parts of East Texas, you will notice they take on the shape of a bow, or "bow echo."  This is because near the center of the line of storms very strong winds are punching in, causing the line to race forward in the center forming the bow shape.  It is here where you usually find the strongest wind in some cases over 80mph.  This is what caused the damage in the Sunrise Shores area of Henderson County.  These strong winds continued to race east affecting parts of Smith County causing widespread power outages and tree damage.

In a highly sheared environment, which we had Tuesday night, sometimes on the ends of a "bow echo" will form an area of rotation called a "bookend vortices."  It is called this because the rotation is located at the ends of the bow shape.  In a highly sheared environment winds will cause this rotation to strengthen.  The environment on the northern counter-clockwise circulation in a highly sheared atmosphere can become favorable for tornado development. Click here to read the complete story...