Please don't tell my girlfriend

I triggered a weird avalanche yesterday up on Gunsight Ridge in the Mt. Hood area. Here's the details:

Elevation 5000 feet
3 inches new snow
Cloud cover, snow flurries with occasional sun flurries
Right about freezing
35 degree slope NE aspect

I noticed snowballs were starting to roll down the hill just after the sun made an appearance around 11 AM. I wanted to move over to a sun-sheltered slope, but I was kind of hemmed in by some large rocks and cornices so I picked a tree'd area for my descent. Then, I had an open slope that I had to cross, so I did a fast ski cut to island of safety, which was a small tree on the other side. As I arrived at the tree, I looked back and the entire slope was doing a slow motion loose snow avalanche. It was probably only about 10mph but it took all the new snow with it.

A wet slide? Or some kind of hybrid slide? There didn't seem to much water involved, but I guess the de-coupling occurs at a microscopic level. I had done some slope tests about 30 minutes before my ski run and everything seemed stable. The late March sun must work really fast. I would have aimed for a more protected aspect, but it had been cloudy and snowing for most of my ascent.

Anyway, after the slide, I had a nice safe route down the mountain. The slide materials were actually very good skiing.

It sounds like it was somewhere between a soft slab/dry snow sluff and a wet slide.  The fact that it moved slowly suggests it wasn't purely your mid-winter variety soft slab.  A few things to consider:  what was the old snow like under the recent snow?  Was it still wet and mushy?  Perhaps the new snow started to sluff and entrained some older, wetter snow.  The mid-March sun can also be pretty intense, and on cloudy days the greenhousing effect of filtered sunshine can quickly heat up and moisten aspects that do not get direct sun like the NE slope you were on.

In general, I'm always leary of conditions like we have now, with extended periods of cloudy weather and light-moderate snow fall that gradually accumulates to significant depth.  The snow only partially stabilizes each day and any sun breaks or the first sunny day can induce lots of wet slides or wet slabs.  The interesting thing is that as the day progresses, the natural activity all seems to start at once, as if some trigger threshold is crossed.  I've gotten caught more than once before in places that I shouldn't have been in these situations and as a result am more aware of them.

The other thing is that ski cutting can be every effective in these situations, as long as the surface snow is loose and not too slabby.

Wow, excellent analysis. Yes, the sliding surface was pretty mushy. I was expecting to ski down on some ice or crust but it was soft and skiable. And yes, the conditions changed extremely rapidly. I understand now why it is important to get out there real early this time of year. Thanks