A series of big storms have impacted the Central Plains and the Mid-South recently.
These storms have produced a tremendous amount of rain, spun off a few tornadoes, caused significant damage in some areas, and produced some incredible satellite images pictures from spotters observing the storms.
This series of storms are called Mesoscale Convective Systems (MS). An MS is a cluster of storms that move as a single system. An MCS can begin as a few storms just a few miles wide and grow to the size of an entire state. Also, an MCS can travel hundreds of miles and last for more than 12 hours.
When observed on satellite or radar, an MCS can initially look like a small cluster of storms and then rapidly grow in a monster of a storm. It can also go from a round cluster to a solid or broken line of storms.
Mesoscale convective systems are very common in the Central Plains and the Midwest. They are responsible for supplying 50 or more of annual warm season rainfall. The storms are driven by upper-level wind patterns and those that impact the Mid-South are often driven into the area by a northwest to southeast flow.
An MSC is fueled by daytime heating and an abundance of moisture typically gaining strength at night reaching its maximum intensity and greatest potential to produce damaging winds and excessive rainfall.
Mesoscale convective systems can form during any season and be responsible for lake effect snow and polar lows in cold seasons and tropical cyclones in warm seasons. As the MCS weakens and eventually dies it can leave behind a mesoscale convective vortex (MCV) which is a counter clockwise circulation that can last for several more hours or even days and become the catalyst for future storms.
A mesoscale convective system is fascinating weather system possessing beauty in structure, the potential to provide life giving moisture to rain starved areas, relief from the excessive heat, as well as the potential to produce widespread damage that can sometimes have deadly consequences.