February 25, 2021

The Extreme Temperature Changes of Texas

 Few places in the world experience more rapid and extreme temperature changes than Texas.

A place whether the temperature can be 80F at noon and 15F by midnight.

A state where a phenomenon called the Blue Norther can produce extreme winds with rapid temperature declines.

And the impacts of these rapid temperature falls can be larger than some hurricanes:  in fact, the effects of this month's cold wave will probably end up being more costly than Hurricane Harvey--both in terms of property damage and loss of life.

Texans Have A Reputation for Thinking They Can Deal with Anything Mother Nature Throws at Them!
Image by Maroonbeard under a Creative Common's Licence

Consider the case Austin, Texas, a city that not a few Northwesteners are thinking of moving to.  Below is a figure that shows the observed highs and lows (black bars), as well as the normal temperature range (green band) and the record highs and lows for February.  

In the beginning of the month, temperatures were above normal, with some days offering highs around 80F.   But then around Feb. 10th, the bottom dropped out, with lows getting to 6F on Feb. 16tth.  And later in the month, they were above normal again.  Texans have to be a tough breed to deal with these changes!


Look closely at the record highs and lows.  Record highs are in the 80s in the early part of the month and around 100F by the 21st, while record lows are in the single digits to the teens.  And it is not unusual to gyrate between the two quickly.

The rapid transition from summer warmth to Arctic cold is not usual in Texas--so frequent that they have a name for it, the Blue Norther.   Sometimes called the Texas Norther.

Moderate blue northers (temperature declines of 10-20F), typically occur several times per year, and the mega-events, like this month (with temperature declines of 30-60F), happen every decade or so.

One of the great Blue Northers occurred on November 11, 1911, where temperatures dropped as much as 70F in less than a day.  The map below, centered over Oklahoma and northern Texas, shows the highs on Nov. 11th and lows on Nov.12th.  Unbelievable.


Such very large temperature declines have been noted as long as Texas has been occupied and is certainly not a new phenomenon.  Texas cold waves are not the result of the "global weirding" that is so popular in the press but a natural part of Texas weather.

But why, you ask does Texas weather, particularly in the winter, have such rapid and severe gyrations?

It is all about geography...and the absolutely unique geography of U.S. Great Plains.

Take a look at this terrain map.  Texas has the broad and high Rockies to its west, which isolates Texas from the temperate/mild effects of the Pacific (which we in the Northwest enjoy in spades). But it is open to the Arctic.... a clear shot from cold air moving south.  Furthermore, the terrain to the west actually helps channel cold air southward, something I did a paper on with Professor Brian Colle of the State Univ. of NY at Stony Brook.


And Texas is also very close to the warm Gulf of Mexico and is at a relatively southern laitude (thus, plenty of strong sun).

So if the flow is from the south (from the warm Gulf) or from the southwest (northern Mexico, with compressional warming as well), Texas can be toasty, even during the winter.  80s to 90s are not unusual from November to February.  

 But then if an Arctic air mass forms to the north, and then pushes southward over the plains, Texas can get primo polar air, backed by strong northerly winds.

No other place in the northern hemisphere is so uniquely endowed for such gyrations between summer-like heat and Arctic cold during the winter.

And it is obvious that in building the infrastructure of Texas--from power generation, to transportation, to water storage and transport--- there must be a consideration of the potential, if not thea certainty, of big temperature swings.  

Texas icing.
Picture by Texugo at wts Wikivoyage through a Creative Commons license

If I was the Seattle Chamber of Commerce, I would be doing some clipping of Texas newspaper headlines:



12 comments:

  1. "No other place in the northern hemisphere is so uniquely endowed for such gyrations between summer-like heat and Arctic cold during the winter." Colorado would like a word (and Kansas/Nebraska). I get you were probably referencing the plains in general. But if you want to live in a yo-yo weather pattern, Colorado front range takes the cake. While it may not get quite as hot, only 80ish in February, the record lows of almost -30F make Texas lows look like a heatwave and the absolute value from record high to lows top Texas. Of course it happens with more frequency, so they are used to it unlike Texas.

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    1. And Spearfish, South Dakota actually holds the world record for biggest temperature change in the shortest amount of time. The swings mentioned here happen all across the plains for sure- I lived in South Dakota and Nebraska for many years, and it is common there in the Spring to have a warm T-short day and wake up to snow on the ground the next morning.

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  2. An excellent, much-needed explanation of what actually happened in Texas recently!

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  3. Thank you, Cliff for the excellent lesson and historical perspective.

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  4. Texas also seems unique in ability to excel in other weather extremes as well- hurricanes + fire + tornadoes + drought + floods + ice storms + excessive heat/humidity.
    They don't have a high earthquake risk, but earthquakes aren't considered weather by most people.

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  5. I always liked the expression "there's nothing between Dallas and the Arctic circle but a barbed wire fence".

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  6. Similar temp swings in both the Cascades and the high desert of SE Oregon.

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  7. A meteorologist for CBS News gets it right,

    “Despite being extreme, it's not nearly as extreme as it could be. Over the past few decades, due to human-caused climate change, the coldest extremes are getting less extreme. As one example, in Minneapolis the coldest day each year is now 12 degrees warmer than it used to be.“

    https://www.cbsnews.com/news/polar-vortex-most-extreme-winter-weather-in-years/

    But In a separate article, a journalist (not a meteorologist) from CBS News gets it wrong,

    “And severe weather is becoming more common, whether it's severe cold in southern states or the intense heat wave in California last year that fueled deadly wildfires.“

    https://www.cbsnews.com/news/texas-power-outage-storm-climate-change/

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  8. A friend from the PNW went to graduate school at Southern Methodist University, near Dallas. He attended a late afternoon football game. Temps were in the 80's, yet many in the crowd were carrying heavy coats, blankets and other winter gear. He was in jeans and a short-sleeve shirt. During the game, the temperature plunged over 50 degrees.

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  9. One of the key takeaways - It will happen again. You can't predict the frequency, but these events are high in impacts to people and infrastructure. Plumbers will have work in Texas for the next year to even partially fix the damage. If Texas keeps its infrastructure management as is the same loss of life, high bills and damages will repeat.

    For those who have worked in Texas energy (I have), these risks have long been known, but the $$$ was good so long as there was not a problem. Incredibly short-sighted thinking, but markets run amok often are.

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  10. I would not want to live in Texas even though the cost of living is alot less the long hot humid summers, hurricanes, deserty or swamp landscape/no mountains, bad infrastructure and lack of consumer protection would be hard to put up with. On a few occasions I have seen Dallas have a higher heat index than Death Valley. I also don't understand how the power company can legally raise their rates 50X when people most need the power, If that is not extortion I don't know what is.

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  11. My dad grew up in Texas. He says "there's nuthin between Texas and the North Pole but a bobwahr fence."

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Please make sure your comments are civil. Name calling and personal attacks are not appropriate.

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