Thanks for the reply Dale.  Using data from https://www.mide.com/air-pressure-at-altitude-calculator, I come up with a correlation at my altitude of P(mbar) = BARO (inHg) x 3.5599 x (T(C) +273.15)^0.3409.  I am just trying to verify that weather stations that report barometric pressure and temperature are being corrected for altitude and temperature for use in APPM model inputs, and that my approach is reasonable.