The cold front intensified as it moved from the eastern to central SRP, with rapid changes in temperature and pressure observed at locations in the southern half of the SRP. Intensification of the cross-frontal temperature gradient in this region appeared to be the result of confluence between southerly prefrontal winds, which experienced downslope warming to the lee of the JarbidgeCaribou Highlands, and terrain-channeled post-frontal winds. Although the rapid changes in temperature and pressure suggested that the front developed the local structure of a gravity current, the frontal motion over the SRP was not consistent with gravity current theory and instead appeared to be the result of advection of the front by the terrain-induced flow field.
The case study illustrates the value of high-density and multi-elevation MesoWest observations for advancing knowledge of frontal evolution over the western United States and improving operational surface analyses. Such observations aid in the identification of large-scale airmass and circulation changes that can be masked by boundary layer processes, valley inversions, and local and mesoscale terrain-induced wind systems.