Does deepening of the polar vortex over North America raise odds of a dry summer?

One vital climate fact hammered into memory from my interview with climatologist Dr. Reid Bryson decades ago: Expansion of the westerly winds over the Northern Hemisphere relates directly to a cool, dry climate in North America. 

February 18, 2021 By Jerry Carlson — The current deep loop in the circumpolar vortex over the U.S. might signal that the global air circulation system is struggling harder than usual to balance air temperatures between polar and equatorial regions. The "river of wind" about six miles high around the top of the world is currently sweeping cold air southward over our country, while allowing warmer air to penetrate farther north elsewhere.

Dr. Bryson's climate research at the University of Wisconsin documented that when northwesterly winds prevail more strongly over Canada and the U.S., winters in our Central Plains are colder — and growing-season storms are less frequent but more violent. Bryson's paleontology studies, published in Climates of Hunger in 1977, showed that in the decades around 1200, Indian tribes were forced to migrate from what's now western Iowa farther south into Missouri, Kansas and Oklahoma.

Today's Midwest growing seasons feature more vigorous spring storms and longer stretches of rainless weeks in late June through August. Cornfields are often dying by late August, rather than staying green until the first hard freeze.

Here's the good news: Weather patterns may become more challenging, but today's weather services and computer power helps you get a clearer picture when bad weather news emerges. Modern meteorology and the internet offer real-time, global tracking of virtually every weather component, including the circumpolar vortex.

Below are a few images you can pull from the internet. Specifically, visit www.windy.com/en for a current worldwide view of major meteorological activity. When you visit the Windy.com site, browse the various settings to see real-time wind directions and velocity, current temperatures, snow cover — most of the vital data is available from around the globe. This site doesn't forecast weather — just compiles everything that's happening now, worldwide.

NOAA also has a rich array of data, but it's a bit more complex to find online.

First, here's a recent view of the circumpolar vortex as you'd see it if you were hovering over the North Pole. The bright red band looping around the top of the world represents stratospheric winds. The current dominant feature is the deep lobe sweeping over North America. The blue pool is a continent-sized airmass flowing southward behind it.

The second of the images below, pulled from www.windy.com/en, shows a flat Mercator-map presentation of high-altitude winds. The website allows you to move a slider up and down to reveal the winds from the surface to 13.5 kilometers high. 

The third image is a screen grab of current surface temperatures worldwide as of Feb. 17, 2021. It's a dramatic view revealing why the southern United States, especially Texas, is struggling with a lack of electrical generating capacity. Already, about 60% of the Rio Grande Valley citrus crop remaining on trees has been devastated, and new growth on groves for next year's crop is also damaged. Note that the blue belt of cold air closely follows the outer rim of the high-altitude circumpolar vortex.