Undular bore, gravity wave again

You may recall the dramatic time lapse video and Doppler radar image of an undular bore in Iowa we posted on this blog back in October. If not, click here. These are relatively rare meteorological events. They are a form of gravity wave train which sometimes forms when thunderstorms, etc, disturb a stable, cold layer near the ground.

Mark Rose, a forecaster at the National Weather Service in Birmingham, made me aware of another bore tonight…in Alabama! It looks like the bore in this case (smaller waves) was moving along with a larger atmospheric gravity wave connected to the line of thunderstorms…something often associated with tropical thunderstorms. When the line and waves came through Auburn, a wind gust of 59 mph was reported, along with wind damage.

Below is the Doppler wind velocity data from the Maxwell AFB radar east of MGM at 925 pm. Note the 5 waves of inbound and outbound velocities (NE and SW) from Clay and Randolph counties down into Chambers county. The strong outbound winds are located near Columbus, GA at this time.

The pressure chart from nearby Alexander City shows the rapid jump in pressure.

This event will require further analysis, and once more data comes back in, I’ll update this blog post sometime Friday afternoon. Neat stuff.

Category: Uncategorized