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Here are two more soundings of possible interest, from Salt Lake City, Utah, on December 4, 1996. This station experienced a cold frontal passage between 00Z and 12Z, so the changes in temperature and moisture are much greater than they were at Fort Worth. Indeed, the whole layer of air below 600 mb has cooled by at least 5 C. This is much more of a change than could be expected just from radiational cooling, and is strong evidence of the cold front.
In both soundings, the tropopause is much lower than at Fort Worth, near 300 mb. This is common: the tropopause is usually lowest near the poles. The 00Z sounding lacks a dry adiabatic layer near the surface (which is at 875 mb), although there is a deep dry adiabatic layer between 800 mb and 650 mb. This suggests that the air above the ground has been heated up over higher topography (the surrounding mountains) and been advected to Salt Lake City.
In the 12Z sounding, there is the classic low-level temperature inversion. At the very bottom of the sounding, the temperature and dew point are identical. This means that the surface air is saturated, and suggests the likelihood of ground fog. Indeed, ground fog was observed at that station.
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