Ongoing avalanche problems in BC interior and n coast mtns
If you are reading the Canadian Avalanche Centre North Columbia, South Columbia, and Kootenay-Boundary public avalanche forecasts (http://www.avalanche.ca/cac/bu.....-forecasts) regularly, the information here is going to be old news. However, things are so strange out there right now, I feel I should once again give folks a bit of a heads up on the ongoing surface hoarror show. (My brother Mark and I came up with the same “hoarror” pun without knowledge the other was doing it. Scary, isn’t it? Mark was first, so credit goes to him.)
After a significant decline in avalanche activity in the Columbia Mountains over the weekend, there was a major increase (400%) in reported activity Monday and that number doubled again on Tuesday. The snowpack just keeps tossing curve balls and I've pretty much stopped trying to predict what's going to happen next. Avalanche sizes continue to be quite large. In a very close call yesterday, 5 people were caught and 4 fully buried in a 350m wide size 2.5 avalanche, which occurred when they were travelling on a 5 day old bed surface; 32 seasons in this business, and I think that's a first for me. This is evidence that what’s starting to feel like a never-ending cycle is not finished yet. I’m getting new images of notable and unusual avalanches regularly and am posting them on our new image gallery. Check out this morning’s additions at: http://www.avalanche.ca/cac/li.....march-2010
After initial indications on the weekend that things were starting to settle down, the most recent persistent weak layer (March 8th surface hoar) went active on Monday with minimal amounts of precipitation: as little as 10-15mm water equivalent/20-25cm fairly light new snow. That’s similar to what happened with the February layers and it’s unusual. Generally it takes 40mm/70cm or so before you’d see this level of increased activity. The February layers have come back to life too. This is now day 28 of high reactivity and/or unusual events on the Feb 8th layer. Crikey! And even deeper layers are suspected in a size 3 avalanche that occurred on March 8th in the Monashees.
The weather forecast suggests a real storm (the first one since so long ago I can’t remember when) is possible later this week, especially in the southern interior. Personally, I’ll believe it when I see it but it’s worth starting to think ahead. There’s quite a lot of uncertainty regarding track and intensity of the storm. In terms of timing though, the next loading cycle looks like it will start Wednesday night and god only knows what havoc that might wreak when it happens. Upslope (W or SW facing slopes) south of the trans-Canada highway will possibly see 20-40mm of water equivalent, which means 30-60cm of new snow. I stress the word possible. But even if we get half that, given the layers we have in the snowpack all heck is probably going to break loose starting Thursday sometime, with elevated levels of reactivity and ongoing weirdness very likely to persist through the weekend. Areas north of the TCH right now look like they’ll get less weather but might still be enough to elevate danger there. And given the uncertainty in the weather forecast, all it’ll take is for the low to track a bit farther north and areas up to Prince George could be affected.
The biggest problems are concentrated exactly on the aspects and elevations where good snow is preserved. Anywhere you are getting good powder riding is highly suspect and should be treated with the utmost caution in the Cariboos, Selkirks, Monashees, Kootenays, and South Chilcotin Mountains. The mountains around Terrace and Stewart are also problematic.
In the coming days, whether we get the storm or not, it's likely to get trickier before there's any chance of it getting better. I’m going into the mountains tomorrow to start my next guiding shift and I intend to go to great lengths in staying away from large terrain features and places where there is overhead hazard. The current and forecast conditions require a high degree of discipline and constant vigilance to maintain adequate safety margins. In our area, we’ve been riding tracks on the same 20 or 25 runs out of 125 in our tenure since early February and I expect we’ll continue doing that for the next week at least. The number of runs we consider safe might even decrease if the snowfall amounts predicted are accurate. In my CAC forecasts, I’ve been saying that extensive experience coupled with professional level training and safety systems are required to manage risk in most areas.
I know I'm telling many of you exactly what you don't want to hear but man, it's weird out there right now.
Feel free to forward this or repost in other venues.
Public Avalanche Bulletins Manager
Canadian Avalanche Centre