I Have to Fix The Isentropic Jack...

I have to make a bit of a correction to my discussion from yesterday.  The reason for the rain with occasional thunder for at least today can be attributed to something called "isentropic lift".  I called it a "weak disturbance", which is WRONG.  Let's fix that.

Here's the definition of that $5 word "isentropic lift".  Simply put, warm air is moving in.  There's cooler air already here.  You may remember from science class that warm air rises, colder air sinks.  Physics says that air masses seek to remain in similar company (equilibrium) whenever possible.  Rather than warm and cold air masses only pushing each other side to side like football players, as warmer air moves in, it will tend to take on a vertical component of motion and leapfrog cooler air under it.  This process is also known as overrunning.  

Think of a car driving the up slope of a local road in your town as the warm air, and the hill as colder air.  That air (the car) is climbing the hill to find similar air to buddy up with - or in this example, find more cars the same style as the one on the hill.  This provides lift - which is one of a few key components of making healthy thunderstorms.  There's not much else besides that going as I write this, since it's not truly warm here yet, so you don't get the really strong storms, but you do get some showers and the occasional low-end  plain vanilla thunderstorm.  That's an oversimplified version of what's making it rain in the South Central Michigan Weather Zone, hopefully you get the idea.  I have to give credit to Maurice Shamell, a degreed meteorologist acquaintance of mine, for clarifying this when I asked him why the models were so wet today in the absence of a true low or upper disturbance.  Again, while I do NOT just rewrite the National Weather Service forecast, there are still many blank spots in my meteorological knowledge that I hope to fill with study, coursework, and reaching out to people such as Maurice, who can help me do a better job for all of you kind enough to read the blog.  Thanks Maurice!  And thanks to my readers for letting me correct my goof!