The first "Main Event"

A dry fall is wrapping up quickly here in Utah as a long plume of moisture stretches across most of the northern Pacific Ocean, advancing toward the coast and aimed at the northern portion of the state. The atmospheric river forecast is below- colors represent Integrated Water Vapor.

 Once it arrives (Saturday) the tap is on. A period of warm air advection gives way to a strong cold front which will kick off the party:



700mb RH, Temp, and Vertical Velocity

After the initial cold front passes, a series of disturbances race along in the current of the jet stream, which riffles north to south like a high volume fire hose that its operator just cant control. The core of the jet at the 300mb level looks to pass over the Wasatch Mountains during the day on Monday. Look at that, 150 knots!



















After that, the current shifts east and we may see snowfall wind down monday night, but I'm not so sure. Overall, I think this will be one hell of a first main event. The favorable dynamics will give us enhanced precip over the mountains, this could be substantial. Lake effect enhancement is possible as well. Winter storm watch is in effect until Monday evening:

http://www.wrh.noaa.gov/warnings.php?wfo=slc&zone=UTZ008&pil=XXXWSWSLC&productType=Winter+Storm+Watch

I just saw on Jim Steenburg's blog that a new experimental forecast shows about 4" of precip through Monday evening at Alta Collins:
http://wasatchweatherweenies.blogspot.com/2014/11/snow-is-coming-but-how-much.html

 Avalanche danger is sure to spike, and as there is little snow cover on the ground anyway (whats there is all facets), we might want to let this one do its thing before running around the the hills.

 Get ready, here she comes.