[MCR] Ice Fall at Johnston Canyon

To add to the recent list from Haffner and Evan-Thomas, this busy morning at Johnston Cyn we were treated to another reminder about the need for awareness of overhead ice hazard right now. In the canyon the sun is beginning to hit the upper sections of the climbing lines -- and the typically healthy curtain of hanging daggers right of the main falls -- just after 10am. I had just finished my briefing about where not to linger when a massive (i.e. 1000kg+) exclamation point detached itself from the highest hanging curtain and punctuated my sentence. Fortunately, at that moment, everyone was well away, so only my syntax was injured, but after the powder cloud and nearby strafing subsided, there were definitely a few other exclamations uttered.... 

For me, this event was just reinforcement of the fact that the recent wide temperature swings of calm bluebird days (-30C on the ground at 1000 hrs, +3C at the lip at 1230 hrs) and the slight-but-strengthening wind-less inversion that's been happening are something to be reckoned with.

As some extra value, over these last few days I've been out, in addition to the am/pm temperature differential and the inversion, the solar effect of the late Feb sun has also been feeling significant. At 1300hrs, while the temperature in the creek was -10, it felt more like +5 in the sun at the tops of the climbs 30m higher. Screws at that point had a lifetime of about 15-20min before they were fully melted out.  So, it's a good time to start perfecting your V-threads. 

Just stay out from under the icicles while you do it.

Carl Johnston

Yamnuska Mountain Adventures

RG, AAG

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