After a VERY wet month of April (5.25″ of rain at the station and 6.77″ at the Allen County Airport) We are headed towards a dry and WARM start to May. The pattern setting up towards the end of the week is typical of this time of year and involves what meteorologists call a “Cut Off” low pressure system. We can see the cut off low in both the 500 mb level (about 20 to 30 thousand feet up) as well as the jet stream level or 300 mb (about 40 thousand feet high)
Here is the 500 mb level by Friday evening. Notice the upper low over the Midwest with the brighter colors indicating higher winds. This low is FAR removed from the main West to East flow which can be seen over Canada.
You can also see the cut off low at the jet stream level with the main flow of the jet into Canada as well. The flow of the jet stream is the main influence in moving storm systems along. With nothing to push the system along it will just sit over the Midwest and spin…..
Eventually this upper level energy will make its way into our region by the weekend, but even then we’ll only likely deal with scattered showers and maybe a thunderstorm. Rainfall amounts Saturday through Monday look pretty low here in the region with the majority of rain being off West where the upper low will spend most of the week.
So thanks to high pressure over the East coast and a cut off low over the midwest we’ll deal with VERY slowly moving storm system over the next several days. You’ll probably hear me using the terms “cut off” low and “blocking” high over the week, hopefully this helps you to better understand!