Pictures from Monday evening

Thunderstorms Monday evening remained below severe limits, but one particular storm was a sight to see near Rockford.  It produced a shelf cloud, followed by gusty winds and heavy rain.

I'm sure many of you have seen them, as they are very common around here.  At first glance, they can appear very ominous and can sometimes be low hanging to the ground.  The lower hanging clouds are often times mistaken for funnel clouds or tornadoes.  The greatest threat with storms that produce shelf clouds are damaging wind gusts and heavy rainfall.  They can form with a line of storms, or a single storm cell (like what we had earlier today).  The air flowing around a shelf cloud is very turbulent, giving it the rough edged look that you often times see.  It's not a wall cloud, but with stronger thunderstorms they can sometimes produce brief, spin up tornadoes.



Meteorologist Tyler Sebree
Rockford, IL

So, how exactly do shelf clouds develop?  All thunderstorms have updrafts and downdrafts.  The updraft is the warm, moist air flowing up into the storm and the downdraft is the rain cooled air.  As the rain cooled air descends in a thunderstorm downdraft, it spreads out once it hits the surface of the earth.  This forces the warm, moist air ahead of the thunderstorm to rise along the leading edge of the storm (often called a gust front).  When the warm, moist air condenses you see the shelf cloud.  Scary looking, yes.  But now when you see these types of clouds, just know that the wind will likely pick up shortly after it passes and you're going to be in for some heavy rain - and possibly hail.

Here are some of the photos you shared with us this evening!  Enjoy!



Bobby Fandel

Mike Hansen
Sublette, IL

Jeremy Dunk
Rote Rd. & I-90 looking South



Josh Strand
Chicago Rockford International Airport



Kim Post
Poplar Grove, IL

Monica Charles
Rockford, IL