Total speculation on my part too but I suspect that if the smoke were influencing the system, it would be in the form of reduced thermodynamic support more than drier air.
— Jack Sillin πΊπ¦ (@JackSillin) September 20, 2020
Mid-level radiative heating due to the smoke plume may make that airmass more stable than usual pic.twitter.com/3lsRdxk6ni