Tuesday, April 26, 2011

Ongoing Lake Effect

Lake-effect snow showers continue over much of the Salt Lake Valley this morning.  It looks like winter out my window.  Wish I was skiing.

As we have seen in some lake-effect events, there appears to be weakly confluent flow over the Great Salt Lake and northern Salt Lake Valley.

An ongoing debate around here concerns the mechanisms for this confluence.  Is it a result of the superposition of the large-scalel southwesterly flow with the thermally forced circulations of the Great Salt Lake, or a reflection of topographic blocking?  Concavities in terrain have been shown to drive confluent flow and increase precipitation rates in idealized modeling studies (e.g., Jiang 2006).  We don't have a clean concavity given the basin-and-range terrain south of the Great Salt Lake, but there likely are concavity effects.  On the other hand, the confluence could be thermally driven.  Perhaps both play a role?

Alta-Collins update: 14" new since 7 PM yesterday.  Snow depth 196".

1 comment:

  1. BOTH! Absolutely nuking flake effect on the sandy bench (<.25mi vis). As for skiing, just waiting for somebody to set the booter up hi boy. 200!