Surface hoar followed the cold clear night.  Photo below depicts how the SH on the northerly aspect contrasts with the SH on the southerly aspects.  Fragile, these SH feathers decay with sun/heating and wind. 

I often wander up from Pine Hollow in American Fork through the campground and up along the ridge separating, loosely, the north face of Timp and what we affectionately call the Wooley Hole.  Down low, It's a reasonably safe ridge walk but one must ultimately exit the open northerly aspen glade at its apex to gain the higher ridge.  I've always considered it a bit spooky - I've moved through there quickly and spread out among partners - thinking that it may slide one day. 

It did during the last cycle.  Maybe 1-2' deep there at 9400'.  35 degrees.  Connected the slope adjacent to the southeast (beneath the red line).  Would've been a nasty ride through the aspens.  At least the north side of Timp had an impressive avalanche cycle from the 18 Jan+ storms.

The view of the 'headwall' one must negotiate.  You can see the debris in the trees (though covered with add'l storn snow.)

Looking down at what awaits the avalanche victim.