Purcells

Snow & wind may begin in earnest Monday afternoon. If it does, danger ratings will quickly rise.

Fair - Intensity of incoming weather is uncertain on Tuesday

Active weather continues for the next few days, culminating with a heavy hitting storm impacting the coast Monday/Tuesday. The current models show the storm breaking up on the coast leaving little precip for the interior. Any potential spill over into the coast would occur on Tuesday, so, we'll have a better handle on that tomorrow. Monday: Strong & well organized system impacts the coast, freezing levels rise to 1400 m ahead of the system. Precip should start up late in the day. 5 - 25 cm are expected late Monday. I know, that's a wild spread in values, but, that's how much disagreement there is in models at the moment. Tuesday: Significant precip may spill over into the interior, or it may not. Again, we should have a better handle on that tomorrow. Freezing level *may* climb as high as 2000 m Tuesday afternoon. Wednesday: Skies clear behind the passage of the cold front, freezing levels sink to the surface.

Avalanche activity slowed down a bit Saturday; control work in the region produced avalanches averaging size 2 on nearly all aspects failing within the recent storm snow and at the March 27th crust/facet combo. One explosive controlled size 3 was reported from the central portion of the region on a steep west facing feature. An avalanche incident occurred Sunday west of Invermere which required organized Search & Rescue. Not other details are known at this time.

The most recent storm produced 20 - 100 cm of total snowfall. The storm snow rests on a layer that is proving to be quite volatile; the March 27th crust/facet combo. This layer, consisting of a melt freeze crust & small grain facets has been quite active over the last 48 hours. Avalanches have been remote triggered on this layer from hundreds of meters away. At lower elevations below treeline the crust was moist at burial which resulted in a more substantial bond.Spring the season has arrived, and it's not just calendar spring either, it's really felt different in the mountains recently. The snowpack is far from isothermic, but the mercury has climbed above 0 as high as 2500m recently. These warm temps have really helped to settle out what now is the mid pack. Slopes below 1000 m continue to experience little or no overnight refreeze (recovery).The spring sun is increasing in strength as each day grows by a few minutes. It takes very little time for S, SE & SW aspects to feel the heat of the sun now, observers report that SW, S & SE slopes are being cooked almost instantly when the sun pokes out. W & E facing slopes are jumping in the mix now too & will be affected by the sun as we enter early April. As soon as the sun comes out, watch for roller-balling & pin-wheeling to start surprisingly quickly. Wet point release avalanches won't be far behind on slopes receiving direct sun.There's a lot of strong snow between recreationists and the February surface hoar layers. There hasn't been a deep slab avalanche in the region since Saturday March 24th. Deep slab avalanches may still be possible. I'm thinking of two different scenarios at the moment:1. The most likely scenario is a large cornice or icefall failure impacting the slope below and producing a very large avalanche. Managing this piece of the hazard puzzle is done by monitoring what's happening above you. Cornices or slopes receiving direct sun are suspect. If you feel like there's a question as to whether or not cornices are warming to their breaking point, then, there's no question, it's time to get off that slope.2. At this point I think the probability of human triggering the deep slab is very low. I don't really want to be proved wrong though, as the result would be large and destructive avalanche 1.5 - 2 m in depth. The most likely location for this type of failure is where the snowpack goes from thick to thin. This is most likely near ridge crests, the edges of slopes and especially around rock outcroppings.