"What's wrong with the weather" is a question that has been asked over andover again. The purpose here is not to get into a heated debate about long-termpattern change, but rather point out what has been going on this month and thissummer in general.This summer has had an extreme weather pattern of sorts. The jet stream isstrong and well south, which has caused quite a bit of weather across theCentral and Eastern states. It has also kept the heat out of the northernPlains, the Midwest and the Northeast. On the other hand, the same flow hasproduced a grueling heat wave in far western North America that recently hasspread all the way to the Yukon.
The easiest way to understand this is to do an experiment with a long stringor rope. Tie one end to a secure structure, stretch the rope out and hold on tothe other end with your hand. Next rapidly flip your end of the rope up anddown. The wavelength you generate is similar to the jet stream pattern. The jetstream would be the rope. How you change the speed of your hand will affect theridges and troughs in the rope.
In summer, the ridges tend to bring hot, dry weather, while the troughsbring rainy, humid conditions. In between, invasions of cool, dry air takeplace.
The trough in the East and Plains has been tearing up the tropics, creatingtoo much wind shear for tropical storms to form. The trough has also led toinvasions of cool air in the Midwest and East. As this cool air has rammed intomoisture from the Gulf of Mexico and the Atlantic, nasty episodes of showersand thunderstorms have occurred.
Farther west, the ridge has been producing above-normal heat in South Texasand the interior western U.S. and western Canada in general. A sharpening ofthis ridge in the past week has led to extreme heat in the Northwest andportions of western Canada.
What has been quite unusual this summer is the persistence of thispattern.
Typically, weather patterns come and go every few days. While some subtlechanges will take place in coming weeks, no big differences in the pattern arelikely in the short term. However, even subtle changes can have bigconsequences. Eventually though, this pattern will change like everythingelse.
AccuWeather.com Expert Senior Meteorologist John Kocet explained theatmosphere's effects on humans the best, "The atmosphere will continue to dowhat it wants. The problem is we often want something else out of a weatherpattern."Kocet added, "The way I see it, there are two choices. You can just acceptit for what it is, or move somewhere else. However, once you move, the patternwill no doubt change, and you may be no better off than you were before." Story by AccuWeather.com Expert Senior Meteorologist Alex Sosnowski
