LESS extreme weather
2 responses | 0 likes
Started by metmike - Nov. 22, 2021, 12:58 p.m.

Below Normal Extremes…2021 Northern Hemisphere Cyclone Activity Below Normal…US Tornadoes Below Normal

https://wattsupwiththat.com/2021/11/21/below-normal-extremes2021-northern-hemisphere-cyclone-activity-below-normalus-tornadoes-below-normal/





Comments
By metmike - Nov. 22, 2021, 1:02 p.m.
Like Reply

My comment:

    Mike Maguire                            

        November 22, 2021 10:02 am


Reduce the meridional temperature gradient(by warming the higher latitudes).........reduce the intensity of the jet stream in between them..........reduce the number of violent tornadoes.


https://www.drroyspencer.com/2019/05/recent-tornadoes-are-due-to-unusually-cold-weather/

https://www.drroyspencer.com/wp-content/uploads/tornadoes-1954-2018.jpg



Also reduce the intensity of extratropical cyclones.


Increased convection though.

Changing available energy for extratropical cyclones and associated convection in Northern Hemisphere summer

https://www.pnas.org/content/116/10/4105


By metmike - Nov. 23, 2021, 3:05 a.m.
Like Reply

    Mike Maguire

                    

           

                Reply to             menace        

        November 23, 2021 12:04 am

        

“Shouldn’t “increased convection” mean more tornadoes not less?”

Menace, if all the other factors that caused tornadoes remained unchanged, then that would be the case……but they aren’t the same.

We obviously need convection present to develop a tornado but you need convection +the right conditions with the convection to cause tornadoes, especially the stronger tornadoes.
One of those key ingredients is a steep temperature gradient from north to south in the Northern Hemisphere.
Global warming/climate change has featured a DECREASE in that key ingredient because of the amount of warming being greater as you move pole-ward………and so we’ve seen a notable drop off of violent tornadoes. 

The places with the MOST thunderstorms don’t have to most tornadoes, which is also evidence of the other factors being needed.   

Places with the most thunderstorms:
https://www.wunderground.com/blog/weatherhistorian/thunderstorms-the-stormiest-places-in-the-usa-and-the-world.html

Region with the most tornadoes…………displaced north and west(into the colder/drier air and where the jet streams are stronger) of the areas that have the most convection/thunderstorms:
https://en.wikipedia.org/wiki/Tornado_Alley

Screenshot 2021-11-23 at 01-42-53 Tornado Alley - Wikipedia.png