The purpose of the Intermountain Precipitation Experiment (IPEX) is to improve understanding of precipitating systems in the Intermountain West. The instrumentation deployed during the field phase of IPEX allowed for detailed microscale measurements of a cold front and associated convection that moved through northern Utah on 14-15 February 2000. The surface cold front was characterized by a sharp temperature drop (8°C in 8 minutes), strong pressure rise (3 hPa in 30 minutes), and wind gusting to 40 m s^-1. Radar imagery captured the shallowing of the leading edge of the wind shift, resembling that of a gravity current. The temperature drop at high-elevation surface stations (2500-3000 m MSL) preceded the temperature drop at low-elevation surface stations (1290-2000 m MSL) by as much as an hour. The pressure rise and wind shift preceded the temperature drop by 15-120 minutes at the surface, thus, the front did not conform to analytic models of fronts (e.g., zero- and first-order discontinuities). Radar and upper-air observations indicate a forward-sloping cloud with mammatus and a 20-hPa deep superadiabatic layer underneath. Shading from this forward-sloping cloud is believed to have produced a 50-m deep surface-based inversion in the prefrontal environment upon which a gravity wave with an amplitude of 0.5°C appeared to be traveling. Downdraft convective available potential energy was 542 J kg^-1 in the prefrontal environment. These and other observations indicate that the forward-sloping cloud was producing snow aloft that sublimated in the dry subcloud air before reaching the surface. This cooling aloft eventually reached the surface and had a clear effect on the structure and evolution of the cold front.

Although the storm-total precipitation associated with this system was generally light (less than 20 mm at all observing sites), the amount of precipitation was strongly a function of elevation. During one 6-h period, precipitation at stations above cloud base (roughly 2000 m MSL) varied widely, mostly due to orographic effects, although precipitation amounts at most stations were about 8-12 mm. At stations below cloud base, precipitation decreased roughly linearly with height toward the surface, consistent with subcloud sublimation. The real-time numerical modeling systems failed to develop saturation and thus did not capture the spatial distribution or intensity of the precipitation.