Extreme Temperature Diary-Sunday June 18th, 2023/Main Topic: “Weird” U.S. Weather That Can Be Blamed on the Jet

The main purpose of this ongoing blog will be to track planetary extreme, or record temperatures related to climate change. Any reports I see of ETs will be listed below the main topic of the day. I’ll refer to extreme or record temperatures as ETs (not extraterrestrials).😉

Main Topic: “Weird” U.S. Weather That Can Be Blamed on the Jet

Dear Diary. The weather this month has been anything but “June like” for the United States and Canada. As I’ve stated over and over again, this can be blamed on a jet stream that has meandered very far north into Canada with a lot of amplification across the North American continent. Another highly amplified pattern will occur this week with yet more heat building in Ontario and Quebec. As discussed yesterday, a weak upper-level low will get stuck over the Southeast, which could produce historic amounts of flooding rain in localized areas:

You can Google the work by Dr. Michael Mann and Dr. Jennifer Francis to see why this weather pattern looks suspiciously like what is predicted by them concerning a climate changed polar vortex.

Here is yet another article pointing to climate change for this “weird” weather…but only at the end of the article, a changing jet stream due to carbon pollution being a “controversial idea:”

Extreme jet stream pattern brings bizarre weather, storms to Lower 48 – The Washington Post

U.S. weather is weird, wild and extreme. Here’s why.

Severe storms are ravaging the South while the coasts are cool and smoke spills south from Canada. Blame the jet stream.

Analysis by Matthew Cappucci Meteorologist

June 16, 2023

Damage from an overnight tornado that has reportedly killed at least three people and injured dozens of others in Perryton, Tex. (Booker Fire Department/Handout/EPA-EFE/Shutterstock)

An outbreak of severe storms, including deadly tornadoes, hail bigger than DVDs and life-threatening flooding, has ravaged the South, coming amid a month of wild weather across North America. Texas is baking beneath heat indexes as high as 120 degrees, the coasts are cool and mostly calm and Canadian wildfire smoke is suffocating much of the northern U.S.

If it seems the weather has been a little bit “off” since the calendar flipped to June, you’re not imagining it — things have been downright weird.

At least 3 dead after killer tornado rips through Texas Panhandle town

It’s all linked to a bizarre jet stream pattern, which is displacing air masses from their typical positions and disrupting the movement of weather systems across the continent.

Though there may be some connection to an emerging El Niño pattern, make no mistake — much of what’s going on is pure chaotic randomness. It just so happens, however, that randomness can sometimes deliver extreme results.

The weird jet stream

The jet stream pattern shown by the American model — valid Thursday night — shows the northern branch of the jet bulging north over central Canadian forming a heat dome while the southern branch zips over the southern United States, energizing storms. (TropicalTidBits.com)

The jet stream, a river of swiftly-moving winds in the upper atmosphere, straddles the divide between cool, drier air to the north and warmer, more tropical air to the south.

Typically at this time of year, as warmth and moisture build north from the Gulf of Mexico and waft over the continental United States, the jet stream gets shunted into Canada. That shifts the main “storm track,” or a highway of strong storm systems that surf the jet stream, to the north. The result is often hot weather across much of the nation with occasional but usually short-lived storminess.

This June, however, the jet stream has been doing anything butwhat it’s “supposed to.” That’s partly because the jet stream has been divided, splitting into a northern and a southern component.

Picture a stone in a river that splits the flow of the fluid moving around it. That’s how the jet stream has been lately. But something else has been at play too — just as stationary ripples can become established downstream of a stone in a river, so too can “standing waves” linger in the atmosphere.

That’s what’s happened over the eastern U.S. — the northern branch of the jet stream has been dipping over the Northeast for weeks, spilling cooler temperatures and sometimes smoke southward into New England and the Mid-Atlantic. That dip in the jet stream has hardly budged.

To the west, however, the jet stream surged north, allowing a heat dome to swell into central Canada. That heat dome, or sprawling area of high pressure, spent most of May and part of June bringing hot, dry air to Saskatchewan, Alberta, Manitoba, Ontario and part of Quebec. The extreme heat — temperatures some 20 degrees or more above average at times — helped sap the landscape of moisture, leaving it ripe to burn.

Meanwhile in the southern U.S., the roaring southern branch of the jet stream has been energizing storms. That’s brewed back-to-back rounds of severe weather, complete with strong winds, tornadoes and “gargantuan” hail — and the pattern doesn’t look to budge soon.

Wild results

The resulting weather pattern has been extreme, and sometimes extreme weather can yield damaging impacts:

Severe thunderstorms

On Thursday, an outbreak of tornadoes and severe thunderstorms led to more than 500 reports of severe weather across the southern Plains, Mid-South and Lower Mississippi Valley. Dozens of buildings were destroyed by a powerful tornado in Perryton, a town of roughly 8,000 people in the Texas Panhandle, where three people were killed.

The National Weather Service Storm Prediction Center predicted hail as big as DVDs, which came to fruition when a chunk of ice roughly 6 inches in diameter fell on Sanger, Tex., just north of the Dallas-Fort Worth Metroplex. The icy bombardment came after a similarly busy day on Wednesday, when 5-inch-diameter hail pummeled Noxubee County, Miss.

Wednesday also featured a spattering of tornadoes in southeast Alabama and adjacent southwest Georgia.

Ordinarily, a “death ridge,” or force field of hot, dry high pressure, becomes established over the Plains by early June, shielding the area from severe weather. That hasn’t happened this year — and so long as the southern branch of the jet stream continues to energize the upper atmosphere, additional rounds of unseasonable severe weather more characteristic of March or April will probably continue.


The overarching pattern, which has featured northwesterly winds over the eastern U.S. and brought cool, continental air to near the Gulf of Mexico, has resulted in a stationary front parked where the air masses meet at the Gulf Coast. That has allowed bands of rain to “train,” or ride repeatedly over the same areas like rail cars on a train track, causing extreme flooding in the Florida Panhandle.

A dire flash flood emergency was hoisted by meteorologists at the National Weather Service on Friday for portions of Escambia County in Florida. More than a foot of rain fell in barely two hours in some places, while at Pensacola’s International Airport, 9.23 inches was measured during a six-hour window. Some locales were closing in on a foot-and-a-half of rain.

Wildfires in Canada

Heat domes, which are made more intense and longer in duration by the effects of human-induced climate change, helped bake the landscape in western and central Canada during much of May. That was because of the jet stream’s northward deviation over central North America, which allowed a bubble of warmth to pinch northward and park for weeks.

The result? Once thunderstorms formed on June 1 and 2, their pinpoint lightning strikes were able to quickly ignite fires across the dried-out landscape. That allowed smoke to pour into the sky, which the jet stream then carried into the United States.

Just last week, Washington, D.C., logged its first Code Purple air quality reading for particle pollution, and skies in New York City turned reddish-orange like Mars. Visibilities dropped to less than a half mile, causing ground stops at major U.S. airports. The Big Apple recorded its worst air quality ever observed.

Extreme heat, but only in southern Texas and the Gulf Coast (and Canada)

Predicted temperature difference from normal averaged over the five-day period Saturday through Thursday next week. (WeatherBell)

As it weaves across the southern U.S., the southern branch of the jet stream has largely kept summer’s characteristic sizzling heat from consistently surging northward into the Plains.

On the other hand, the dipping northern branch of the jet stream has kept the Ohio Valley, Midwest and Northeast cooler and drier than average. Washington, D.C., was 2.2 degrees below average in May and is running 1.6 degrees below average for June. Its trademark humidity has been absent while scant rainfall has also allowed the expansion of moderate drought across the Mid-Atlantic, and the deficit continues to grow.

The only place experiencing consistently hot weather has been South Texas and the Gulf Coast. Excessive heat warnings are up for Corpus Christi, San Antonio, Austin, Houston, Waco, Lake Charles and New Orleans; Dallas-Fort Worth is under a heat advisory.

In the excessive heat warning area, heat indexes of 110 to 120 degrees will be widespread, causing a grave danger to those who can’t escape the heat. Actual air temperatures in most locales will range around either side of 100 degrees for the forecastable future.

Some of the worst of the heat is south of the border in Mexico, where the core of the high pressure zone supplying the heat to southern Texas is centered. Mexico City posted its highest June temperature on record Thursday.

Where it’s cool

On the West Coast, onshore and northerly flow has kept things cool; Los Angeles was 2.4 degrees below average for May, while San Francisco and San Diego ran 1.6 and 2.3 degrees cooler than normal, respectively. The relatively cool weather has slowed the melting of a record-setting snowpack in California, averting a potential flood disaster.

Is there a link to El Niño?

Sea surface temperature differences from normal. The yellow-orange-red shades indicates warmer-than-normal oceans and the plume off the coast of South America is a key indicator of El Nino. (earth.nullschool.net)

El Niño, a broad-scale weather pattern now developing, begins with a warming of waters in the eastern tropical Pacific Ocean. That, historically, has been linked to split-flow jet stream patterns like the one driving wild weather across parts of the Lower 48.

Natural variability, a.k.a. randomness, is also a big player, but it stands to reason that the two factors, overlapping together, are in large part culpable for what we’ve been facing.

El Niño is looming. Here’s what that means for weather and the world.

Some scientific research also suggests human-caused climate change may increase the chances of slow, wonky jet stream patterns such as the one being observed this summer. The idea is that the disproportionate warming of the high latitudes is reducing the temperature contrast between the north and south, weakening the jet stream and thus causing it to take bigger dips and meander more. It remains a controversial idea.

Jason Samenow contributed to this report.

Here are some “ET’s” recorded from around the planet the last couple of days, their consequences, and some extreme temperature outlooks, as well as any extreme precipitation reports:

Here is more climate and weather news from Sunday:

(As usual, this will be a fluid post in which more information gets added during the day as it crosses my radar, crediting all who have put it on-line. Items will be archived on this site for posterity. In most instances click on the pictures of each tweet to see each article. The most noteworthy items will be listed first.)

Today’s News on Sustainable Energy:

More Environmental Stuff:

And from the Weather Department:

More on other science and the beauty of Earth and this universe:

If you like these posts and my work on record temperature ratios, please contribute via the PayPal widget, which has recently been added to this site. Thanks in advance for any support. 

Guy Walton… “The Climate Guy”

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