Jet Stream Over US So Weak Weather Systems are Moving Backwards
An extreme US summer that has featured floods and heavy rains in the east and drought and devastating fires in the west boasts yet one more bizarre weather pattern: a backward moving storm system.
As of last week, a strong frontal boundary had swept into the southeastern US bringing with it another dose of heavy rains and storms. Then the system stalled. Over Friday, Saturday and Sunday, the front and associated low pressure systems have backed up, moving from east to west, passing over the Appalachians, then the Tennessee River Valley, then the Mississippi, until today it reached a central region stretching from Texas all the way north to the Dakotas.
This retrograde weather is a very uncommon, but not unheard of, event. In the context of an already strange summer, it adds yet one more anomalous weather pattern to the list. In the AQUA/NASA image below, we can see the position of this retrograde frontal boundary and low pressure system as of yesterday. Note how the eastern front essentially collapsed as it pushed westward forming a bow from Texas to the Dakotas in the image at the top of this post.