What is a "Linear" storm

[John Diel]

In several posts, one will see someone say "the storm went linear". What does this mean?

 

[Jeff Snyder]

Linear just refers to the orientation/shape of the storm... There is a semi-common tendency for storms to move from cellular in shape to more linear in shape -- such as a transition from a multi-cell cluster or supercell to a squall line. This transition tends to nean a transition to an 'outflow dominant' storm type, one which sees its development and propagation dictated more so by convergence along a leading gust front than much else. Oftentimes, these storms are tilted upshear, resulting in a front updraft / rear downdraft sort of configuration... Squall lines tend to provide an unfavorable environment for tornadogenesis...

 

[Tony Laubach]

A squall line basically...

Took me a while to realize what they meant when they said a storm was "going linear". That means that the storm is turning into more of a squall line (or merging with an existing one) from a cellular storm. If you're chasing a storm and hear it's going linear, it means that it's going to turn into a big black line of death and you don't want to waste your time with it if there are better (non-linear) storms elsewhere!