Snow Alerts for the Backcountry, Not Just the Resort

Read this first

A snowfall alert is not an avalanche forecast. Nothing on this page, and no app described on it, assesses avalanche hazard. Snowfall totals are one input among many, and new snow is the single most common trigger for avalanche activity — which means an alert saying “30 cm overnight” is a reason to be more cautious, not a green light.

Before you travel in avalanche terrain, read the forecast from your regional avalanche center — Utah Avalanche Center, Colorado Avalanche Information Center, Avalanche Canada, SLF, Meteo France, or whoever covers your range — every single time. Carry a beacon, shovel and probe, know how to use them, and take a course. That forecast is written by people who were in the snowpack this week. No amount of forecast data substitutes for it.

With that stated plainly, here’s the narrower thing forecast alerts are good for: knowing that snow arrived somewhere the resort report doesn’t cover.

Why resort numbers mislead for a trailhead

Resort snow reports measure at the resort, usually at a base area or a mid-mountain stake. If your objective is 10 km down the road and 600 m lower, that number can be wrong in either direction by a lot:

• Elevation. The rain/snow line is the single biggest variable in a marginal storm. A resort reporting 25 cm at 2,600 m may correspond to rain at your 1,700 m trailhead. The reverse also happens — a high shoulder can pick up far more than the base.
• Aspect and orography. Storms load specific drainages. A range with one resort on its west side tells you very little about the east side in a westerly flow.
• Distance. 20 km is a different storm. In lake-effect or convergence-band terrain, 5 km is a different storm.
• Measurement incentive. Resorts are not neutral parties in reporting their own snowfall.

So if you’re planning around a resort’s number for terrain that isn’t the resort, you’re using a proxy without knowing its error.

Picking coordinates that mean something

If you’re going to monitor a point, choose the point deliberately.

Monitor your objective’s elevation, not the trailhead. You care about conditions where you’ll be skiing. If the trailhead is at 1,700 m and you’re skinning to 2,600 m, a coordinate near the upper elevation is more relevant — even if it’s less convenient.

Pick a representative spot, not a summit. Ridgetops and summits are wind-scoured and model poorly. Something mid-slope in the drainage you actually ski is more informative.

Get the coordinates precisely. In Apple Maps or Google Maps, right-click the spot and copy the coordinates. In CalTopo or Gaia, tap a point and read them off. Four decimal places is far more precision than any forecast model has, so don’t agonize — but do get the right drainage.

Consider two points. One at your objective’s elevation and one lower, so you can see where the snow line landed. This is often more informative than either alone.

Doing it yourself, free

The DIY route in how to get powder day alerts on your Mac works for arbitrary coordinates — it’s a shell script plus a launchd job, and since it takes latitude and longitude directly, a backcountry point is no harder than a resort. If you’re comfortable with a plist, that’s a complete free solution and you don’t need to buy anything.

The limitation you’ll hit fast is that one script watches one point, and comparing two elevations means duplicating everything.

Reading the numbers alongside wind and temperature

New-snow totals alone are thin information. Two things change their meaning:

Wind. 20 cm with calm winds and 20 cm with a 60 km/h west wind produce completely different snowpacks — the second builds wind slab on lee aspects. Windy is the best free tool for this, and wind is precisely the variable a snowfall alert doesn’t capture.

Temperature through the storm. Snow that starts warm and ends cold builds upside-down layering. A single daily total hides that entirely.

Both are reasons to treat an alert as “go look at the real forecast”, not as a conclusion.

Where Powder Alert fits

I built Powder Alert, so this is the author’s section.

Its relevant feature for backcountry use is custom locations: drop a pin anywhere on the map and it monitors those exact coordinates with the same logic it uses for built-in resorts — your threshold, your daily check time, the same storm-cycle detection. You’re not limited to the 165+ resorts in its list, and you can watch several points at once, which is the thing the DIY script makes tedious.

What it does not do, stated explicitly: it does not assess avalanche hazard, it does not know about wind loading, it does not replace your avalanche center’s forecast, and it should not factor into a go/no-go decision in avalanche terrain. It watches a number and tells you when the number is big. That’s the whole feature.

Its data is Open-Meteo model output, so it inherits the accuracy limits of any model forecast, and it’s $4.99 one-time.

The honest summary

A forecast alert for backcountry coordinates solves exactly one problem: it stops you from using a resort’s number as a stand-in for a place that isn’t the resort. That’s genuinely useful for deciding whether tomorrow is worth setting an alarm for.

It solves nothing about whether the terrain is safe to be in. Those are different questions, answered by different people, and only one of them is answered by software. Check your avalanche forecast.