For the first time in a long time, I can say that the weather this week looks active. We haven’t seen very active weather across this portion of the world, and it has been killing me.
However, this week, we are likely to see a very strong, rapidly intensifying low pressure system form, and impact the midwest. This will bring strong winds, blizzard-like conditions, and severe weather to much of the Midwest. But what is behind a low of this strength and magnitude?
Well, this biggest factor in this is the presence of strong mid and upper level jet dynamics. Without these dynamics, we lack to ability to force and develop a strong surface low. This system has all of the jet dynamics present to form a strong, rapidly intensifying low pressure system.
Jet stream dynamics are fairly complicated, and I won’t explain them in detail, but there are regions within jet streams and streaks called the Exit and Entrance regions. The idea is that in portions of these regions there are more favorable regions of rising and sinking air. The common idea that the “Right Entrance Region” and “Left Exit Region” both have areas of diverging air, creating a favorable environment for precipitation, and surface lows to form.
In general, the exit region of the mid level jet is typically where you are going to find a low pressure system. Because air diverges in the mid and upper levels of the atmosphere here, it must converge at the surface, and rise. This creates a void in the pressure field, creating a lower pressure area.
The strength of the mid and upper level winds are what is driving this low pressure system to be awesome, and fairly strong! With anomalously low atmospheric pressure systems, you will often find stronger jet streaks, and at the surface, strong low pressure systems.
Now this isn’t all that goes into the making of a strong low pressure system, but it is one of the more significant aspects in the formation of one! Now, go tell all your friends about it, because it is pretty awesome.