By Herb Fischer
The spontaneous, local downpours of summer are giving way to features you can track on a map now. Henry and other experts call these synoptic systems.
The past summer was so hot and humid at times, that simply a a small cold pool or height drop in the upper atmosphere could trigger a drenching thunderstorms complete with impressive downdraft winds and hail!
However, now that the jet stream is strengthening and bowing further south at times, big pressure systems and cyclones are becoming larger-scale and appear clearly on the weather maps. When they get close enough together, the pressure gradient between them cause howling winds over a much larger area than the summertime.
It’s amazing how you can often see this difference between summer and winter with the naked eye!
The drama of a winter storm arrives in stages, first as cirrus coming from the southwest horizon, then with a gradual lowering of the cloud deck, until the nimbostratus deck follows lockstep near the storm’s counterclockwise circulation.
In the summertime, it seems the atmosphere waits for no introductions. The hot, humid air seems to do all the work as the building cumulus seems to bubble up, home-brew, overhead. And if everything clicks, the atmosphere seems to collapse right away with a boomer!
Yet I think winter has its own microbrew in spots! What a novelty lake-effect is! You can get prodigious accumulations of snow on the lee of the Great Lakes, without any synoptic large-scale feature!