An air mass over Seattle, WA has a temperature of 15°C and a dewpoint of 12°C at sea level. As it travels from west to east it is pushed up over the Cascade Mountains and then down the eastern slope toward Spokane. Use your understanding of adiabatic cooling and heating, dry and wet/moist adiabatic lapse rates and condensation to answer the following questions. Use the following rates in your calculations: DAR = 10°C / 1000 m; MAR = 6°C / 1000 m. Assume that all water condensing in the atmosphere falls as precipitation.

1) What is the specific humidity of the air mass at Seattle? What is its relative humidity?





2) By how many degrees must the air mass be cooled before it reaches saturation?





3) What is the elevation of the lifting condensation level? What is the air temperature, specific humidity and relative humidity at the lifting condensation level? Show your work.







4) What is the air temperature, specific humidity and relative humidity at the summit? Show your work.







5) What is the air temperature, specific humidity and relative humidity at Spokane? Show your work.