Why do MCS/MCC's form at night?

Jeff Duda

EF6+, PhD
Staff member
Supporter
Oct 7, 2008
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Broomfield, CO
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That statement is not entirely true - plenty of MCSs and MCCs form during daylight hours. However, probably the leading explanation underlying that statement is the forcing from the nocturnal low-level jet. During the daytime, cellular storm modes are usually preferred given the more heterogeneous nature of forcing to trigger convection (although even that is not always true).
 
Mar 28, 2016
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Hyannis, MA
That statement is not entirely true - plenty of MCSs and MCCs form during daylight hours. However, probably the leading explanation underlying that statement is the forcing from the nocturnal low-level jet. During the daytime, cellular storm modes are usually preferred given the more heterogeneous nature of forcing to trigger convection (although even that is not always true).
I noticed that a lot of these constitute part of the STL areas "big" events. They come through the area during the morning hours, setting the stage for the main event in the afternoon/evening hours.