Cold Pools

[Michael Riedl]

This is an area of convective weather where I just can't seem to wrap my head around. It isn't necessarily for storm chasing or tornadic potential but I would just like to understand what exactly a cold pool is, what it does, and how it is formed.

I recently took a module at Met Ed about Cold Pools and shear and horizontal vorticity. Somewhat confusing for me. Basically I am asking for an explanation of Cold Pools, how they form, and how they influence further convective development.

 

[Jeff Duda]

Cold pools are nothing but storm-scale cold air masses. They are produced by both downdrafts from thunderstorms that bring rain-cooled air from aloft down to the surface and from wet-bulbing at the surface from evaporation of rain near the surface and the subsequent latent cooling. Again, think of the leading edge of a cold pool (i.e. and outflow boundary or gust front) as a cold front on a smaller scale. Thus cold pools provide lift due to convergence and density differences. Squall lines and MCSs typically form as a result of cold pools from multiple storms combining into one big one and surging. This usually results in a forward-propagating squall line as the cold pool surges. On the flip side, a cold pool results in stable parcels, so you will not see surface based development within a cold pool.