Visitor Put up by Willis Eschenbach
That is an extension of my earlier put up entitled “February Fantasy Versus Actuality“. Please learn that to get the fundamental concepts. To recap, a research in Science journal stated
Regardless of the speedy warming that’s the cardinal signature of worldwide local weather change, particularly within the Arctic, the place temperatures are rising rather more than elsewhere on the planet, the US and different areas of the Northern Hemisphere have skilled a conspicuous and more and more frequent variety of episodes of extraordinarily chilly winter climate over the previous 4 a long time.
…
The Arctic is warming at a price twice the worldwide common and extreme winter climate is reported to be growing throughout many closely populated mid-latitude areas, however there isn’t any settlement on whether or not a bodily hyperlink exists between the 2 phenomena.”
To check this declare of accelerating “extreme winter climate”, in my earlier put up I regarded on the common February temperature of the continental US to see if it was cooling. It hasn’t been cooling.
Nonetheless, a few commenters appropriately identified that the difficulty mentioned within the research was not common temperature. As an alternative, the authors have been speaking about “episodes of extraordinarily chilly winter climate” akin to these Texas skilled in February of 2011 and 2021.
On the lookout for a extra correct measure of extraordinarily chilly winter climate, I acquired the every day temperature knowledge for the Southern Nice Plains from NOAA. Right here’s a map of the realm in query.
Determine 1. Map of the Nationwide Local weather Evaluation areas.
Then I calculated the usual deviation (a measure of how broadly unfold out the temperatures are) of the February temperatures. I reasoned that if there have been brief sharp chilly spells, the usual deviation can be bigger.
Determine 2. Normal deviations of February minimal every day temperature for the Southern Nice Plains. Chilly spells are indicated by a rise in the usual deviation.
In Determine 2, we are able to clearly see the Texas chilly spells of 2011 and 2021. However is there a “conspicuous and more and more frequent variety of episodes of extraordinarily chilly winter climate over the previous 4 a long time”?
Effectively … in a phrase, no. Determine 2 exhibits there was a critical chilly spell in 1951. And the Texas State Climatologist agrees, saying:
Jan.–Feb. 1951: Freeze. On Jan. 31.–Feb. 3 and once more on Feb. 13–17, chilly waves swept over the whole state, bringing snow and sleet. Heavy harm was performed within the Decrease Rio Grande Valley to truck and citrus crops, notably within the earlier of those northers. Throughout the norther of Jan. 31–Feb. 3, the temperature went to –19°F in Dalhart.
Nonetheless, in the course of the thirty years after 1951, there was little in the best way of “episodes of extraordinarily chilly winter climate” till the last decade and a half from 1981 to 1996. Throughout that point there have been a variety of chilly episodes, though not as intense as in February 1951. Within the coldest of those, in February of 1985, San Antonio acquired a uncommon snowfall, they usually noticed the coldest day ever recorded in Midland, Texas.
Nonetheless, within the quarter century since 1996, there have solely been the 2 extraordinarily chilly spells talked about above, in 2011 and 2021.
If we divide the 72 years of the file into three 24-year intervals, we’ve just one “episode of extraordinarily chilly winter climate” within the first interval; six considerably hotter episodes within the second interval; and solely two episodes in the newest 24 years.
So no, within the Southern Nice Plains, there’s not a “conspicuous and more and more frequent variety of episodes of extraordinarily chilly winter climate. Neither is “extreme winter climate … growing” as they claimed. Neither of these statements is true.
Then I assumed, “Effectively, possibly I’m trying too far south. Perhaps the claimed impact is seen within the Northern Nice Plains”. So it was again to the drafting board, and right here’s what I discovered.
Determine 3. Normal deviations of February minimal every day temperature for the Northern Nice Plains. Chilly spells are indicated by a rise in the usual deviation
Though there’s higher variation within the February minimal temperatures within the Northern Nice Plains NCA area, the identical state of affairs prevails as within the Southern Nice Plains—one February “episode of extraordinarily chilly winter climate” within the first 24 years, a half-dozen or so within the center 24 years, and the 2 chilly Februarys in 2011 and 2021 within the last 24 years. And there’s no pattern within the knowledge.
One other stunning idea runs arduous aground on a reef of ugly details.
Finest to all,
w.
Knowledge Entry—I’ve put the 72 years (1951-2022) of every day Southern Nice Plains temperatures, each maximums and minimums, in my Dropbox for obtain. It’s a reasonably small file entitled Nice Plains South nClimDiv.csv, 588 KB, in CSV format so it may be opened in Excel or different packages.
My Ordinary—I can defend my very own phrases. I select them very fastidiously. I can’t defend your (mis)understanding of my phrases. So please, whenever you remark, quote the precise phrases you might be discussing.
