Picking Where to Ride: From the Whole Range to Your Slope

Two searches

Picking where to ride is two searches. The coarse search picks the region: where the storm went, where it stayed cold, which bulletins read better. The fine search picks the spot inside it: the few slopes you'd actually ride, each with its own height, aspect and terrain.

Snow Doctor does both the same way. It puts the places side by side, one row each, with the numbers that tell them apart. You read across, see the difference, and open the one you want to know more about.

See: the snow map shows where the snow, the freezing level and the danger fall.
Line up the regions: Compare puts them in one grid.
Narrow it to your spots: pick the zones you're weighing and line those up.
Read the one you pick: its full report.

1. See: the snow map

The map colours every Avalanche Canada forecast region in BC and the Rockies by snowfall, by that day's highest freezing level, or by the highest danger rating. Pick the days on the strip along the bottom, two days back to two ahead, and one look shows where the storm went. Tap a region for its preview: the danger at all three elevation bands, that day's snow with the snow before it, and the highest freezing level. The full report is one more tap.

How the colours and numbers are made has its own post: How the snow map works.

2. Line up the regions

Tap Compare and the regions on screen line up in a grid, or just your favorite regions, from the small switch at the top. Each region gets one row and four boxes:

Snow: the new snow on the day you pick.
Snow before: what fell on the strip's days before it. For today, that's the two days before. Under its name it says which days, like "Sat to Sun".
Max Fz: that day's highest freezing level.
Danger: the region's highest rating that day.

Two phone screens. First: Garibaldi's preview over the map, with the day strip, Considerable at alpine and treeline and Moderate below treeline, 6 cm of snow today with 10 more Saturday to Sunday, and a highest freezing level of 1,400 m, above a Full report button. Second: Regions on screen in the compare grid for today, eight Sea to Sky regions sorted by snow, from Ashlu at 9 cm down to the Duffey at 1 cm, each with its snow before, highest freezing level and danger in shaded boxes. — A region's preview, and the regions on screen lined up. Numbers are illustrative.

Every box is shaded on fixed steps for its column. Darker means more of that thing, never better or worse. The steps don't change, so 10 cm looks the same on every day and in every row, and a pattern shows before you read a single number. Danger keeps its usual colours. Tap a column title to sort highest first, and again for lowest first.

3. Narrow it to your spots

A region can take in sea-level inlets and icefields. The day happens on a few slopes, so the next step is your own. In My Zones you save the spots you ride, each with its elevation band, aspect and ATES terrain rating. Drop a pin and Snow Doctor fills those in for you, with the band read from what grows there and the local tree line, and you confirm.

In Compare, switch the menu to My zones. The first time, it lists all your zones, nearest the middle of the map first, so moving the map reorders them. Tick the ones you're weighing; they stay pinned at the top. Search finds a zone by its name or its region, and a star marks a favorite. Your picks can span three regions: comparing across them is the point.

Then each zone gets a row, with eight boxes:

Danger: the rating at the zone's own band, not the region's highest.
Problems: how many of the bulletin's avalanche problems sit on the zone's band and its aspect.
ATES: its terrain rating, 1 to 4.
Snow and snow before: as for regions, at the zone's own spot.
Sky: daytime cloud, in words: clear, some cloud, flat light or socked in.
Wind: the day's strongest wind at the zone's height.
High: the day's high temperature there.

Two phone screens. First: Pick zones, with Columnar East face and Black Tusk South ticked and pinned at the top, and the rest of the zones listed nearest first with their region, band, aspect and distance, above a Compare 2 zones button. Second: the My zones grid for today, four Garibaldi zones sorted by snow, each with its danger at its band, problems on it, ATES rating, snow, snow before, sky, wind and high in shaded boxes, a minus button to remove each, an Add a zone box and a pencil button. — Picking zones, nearest first, then the grid. Numbers are illustrative.

Next time, Compare opens straight on the grid with your picks. The minus next to a zone takes it out, the box under the grid adds one, and the pencil opens the full list again.

Each zone's own forecast

A zone's weather isn't its region's. It's a forecast for that exact spot and height, from Environment Canada's GEM models, the same family as everything else in the app, refreshed twice a day. It's the same forecast the zone's preview and full report show, so the grid, the preview and the report never disagree.

That's also why you pick. Each zone's forecast is its own request, and on a given day you're usually weighing two or three spots, not every zone you've ever saved. You can pick up to 10 at a time.

4. Read the one you pick

Tap a row, or a pin on the map, and its preview opens. One more tap opens the full report: the bulletin, the weather at three heights, the simulated snowpack, field reports, and Doctor's Orders, our written read of all of it. Regions, zones, resorts, cabins and mountains all open the same kind of report, so once you've read one, you can read them all.

Resorts, cabins and mountains have previews too, read at their top height: a resort's top, a cabin's hut, a mountain's summit. They aren't in the compare grid. It's for regions and your own zones.

Why there's no score

Saved zones used to carry two scores: an avalanche list that took points away for what counted against a zone, and a weather score you could tune. They read the right things, but they were a lot to look at, and a number on a slope invites you to trust the number instead of what's behind it.

The grid shows the same things as plain facts. Nothing is added into one score, and no row is marked best. Avalanche Canada advised against go or no-go guidance, and we agree. Snow Doctor lines the facts up. The call is yours.

What it can't see

Your exact line. A zone's forecast is for one spot. The models see the mountains in squares 2.5 km across at best, so a gully, a lee slope or a sun crust is smaller than anything they can resolve.
Wind loading. The wind column is wind speed, not where the wind moved the snow. The bulletin's wind slab problem and what you see on the skin track fill that gap.
Problems by name. The problems box is a count. Open the zone to see which ones and what the bulletin says about them.
Terrain nobody rated. Most terrain has no ATES rating. An empty box means unrated, not simple.

None of this replaces the avalanche bulletin, field reports or what you see on the ground.

Credits

Weather models (HRDPS, RDPS and GDPS) from Environment and Climate Change Canada, via MSC GeoMet and Open-Meteo. Data Source: Environment and Climate Change Canada. Contains information licensed under the Data Server End-use Licence of Environment and Climate Change Canada.
Avalanche Canada and the other forecast centres for the bulletins, region outlines and ATES ratings.

Questions, or a column you'd want in the grid? Write to hello@snowdoctor.ca.

Go ski good snow.