A snowstorm was predicted in Chicago. Identify the possible upper air temperature, surface temperature, and air pressure of Chicago on that day. Normal atmospheric pressure is 29.9 inches of mercury.

If a snowstorm is predicted in Chicago, then the conditions should be

upper air temperature = low

surface temperature = high

air pressure = low

For a snowstorm to occur, warm air must rise above cold air. The pressure must also be below atmospheric pressure.