That calculator is tricky on barometric pressure. There is a high elevation example given just above it that helps.... thanks on the barometric pressure response. It request an ambient and wasn't sure if that implied weather channel adjusted values or for the unadjusted value that's typically based on altitude alone. That's why I posted both responses so as to give the driver an idea of what possible range to expect, even though one side maybe more realistic than the other (which is more along the ~25-28% range from what I have seen.
Thanks for the corrections!
There is also a NHRA basic ET correction factor for elevation, ignoring heat and humidity
NHRA Altitude ET Corrections