Monday, January 28, 2019

Creme-de-la-Creme of Cold Air

If I remember correctly, my colleague Lance Bosart, who has been a Professor of Atmospheric Sciences at the University at Albany for 50 years (see this American Scientist article), considers -40ºC the "creme-de-la-creme" of cold at at 850 mb.  

The NAM forecast valid 1800 UTC 29 January (10 AM CST Tuesday) has a small patch of sub -40 850 mb air over northwest Minnesota. 

No point in specifying F or C since -40 is the magic temperature at which the two scales converge (i.e., -40ºF = -40ºC).  

Glad to be watching it from half a world away.  For Utahn's, be grateful you are on the western side of the continental divide.  


  1. The Arrowhead 135 is taking place right under that cold bit as we speak! There are people out running and biking and skiing in that frigid cold....

  2. In addition to -40F and -40C being the same temperature, that is also the temperature at which homogeneous nucleation occurs in supercooled water producing ice crystals. :)