The presence of altostratus clouds (upper right of photo above) and lenticular (mountain wave) clouds has certainly helped paint the scene, but I'm wondering if we might have some aerosols, possibly Asian dust or pollution, moving over us in the upper atmosphere to give us a bit more orange tint than usual. Perhaps someone can dig in and have a look as I have other important things to keep me busy today.
After a sunny day today, things are looking pretty active for Thursday through Saturday and possibly Sunday as two major troughs embedded in the southwesterly to westerly large-scale flow rumble through the state. There is a lot going on, so I'll summarize quickly with two graphics from the 1200 UTC NAM. The first is the total precipitation (snow water equivalent) produced by the NAM through Saturday afternoon showing more than 5 inches over portions of southern California, more than 1.5 inches in portions of southwest Utah, and up to 2 inches in the northern mountains of Utah.
Both storms contain atmospheric rivers, filaments of strong moisture flux with a subtropical tap. In contrast to the previous atmospheric river events we've seen the past few weeks, the atmospheric rivers in these events interact with the high Sierra. During the first event, for example, low-level flow deflection upstream of the Sierra combined with the depletion of water vapor by heavy precipitation over the Sierra and upstream ranges of southern California, means that the strong atmospheric river conditions do not penetrate directly into northern Utah. You can see this to some degree in the image below.
Whatever the northern Wasatch get out of this storm, it would have been more if it wasn't for the high Sierra.
The formation of a cyclone, a large-scale area of low pressure, is known as cyclogenesis. Explosive cyclogenesis is the rapid formation of a cyclone, generally defined as having a deepening rate of either 24 mb in 24 hours or 18 mb in 12 hours at 60ºN latitude. Because it is more difficult for a cyclone to deepen at lower latitudes, equivalent deepening rates at 35ºN are 16 mb in 24 hours and 10 mb in 12 hours.
The second in this series of storms produces an explosively deepening cyclone off the coast of California that is forecast by the NAM to have a central pressure of about 975 mb at 0300 UTC Friday (2000 MST Thursday).