I’m planning an early summer section hike through the Trinity Alps on the PCT southbound from Callihan’s to Castle Crags. I’m trying to calculate a decent start day (aka Ray Day) assuming average snowpack. I realize each year is different depending on snowfall; I’m just looking for a benchmark.
The chart below is for snow water equivalent at Peterson Flat Snotel from 1999-2022. The snotel is at 7150′ on a SW-facing slope near PCT m1535. The average melt-to-zero day there is May 20. In 7 of 23 years (30%) snow lingered past June 1. In only 1 of 23 years (4%) snow lingered past June 15 (melting to zero on June 18, 2010). Note: data is missing for 2023, a high snow year. I’m assuming snow will linger in patches and on north-facing slopes well past the zero melt day.
Constraint: I’m okay walking for short stretches on snow (< 1 mile), but I don’t want to posthole all day, and I don’t want to sleep on snow. I’d like to skip ice axe if possible. Microspikes are okay.
Question: what’s a reasonable Ray Day for the Trinity Alps? Would 2-3 weeks past zero melt (i.e. June 10-15) be a good conservative estimate? And do the above assumptions sound reasonable? or am I totally off base here?
Any other tips you folks might have for me for planning an early summer trip to the Trinity Alps?
