The terrain check
A gravel loop that is perfect in July can be porridge after a wet week and under snow in April. The terrain check says which it is today.
Linje reads the rain of the last three days where your ride starts, last night's low and, in Norway, the snow along the route, and gives the terrain one word: snow, frozen, soft, wet or dry. A sentence under it says why.
Try the rules
The same rules, in the same order, with the same sentences as the app. The first rule that fits wins.
Five words, in order
The rules are checked in this order and the first that fits is the word. Snow on soft ground is still snow to a rider.
| Word | When Linje uses it |
|---|---|
| Snow | In Norway: snow down to where the ride starts, or at least 200 m of the ride off tarmac where the snow is 3 cm deep or more |
| Frozen | Last night fell to −1 °C or below, on a ride at least a quarter unpaved. Linje says when it is expected to thaw: hard until about 11:00 |
| Soft | 12 mm of rain or more in three days, on a ride at least a quarter unpaved |
| Wet | 1 mm or more in the last day |
| Dry | None of the above |
The sentence under the word says how much fell and what it means for the gravel: under 4 mm in three days, expect it dry; then damp, soft from 12 mm and heavy from 30 mm. A route that is almost all tarmac is told so plainly, because rain does not change how a road rides. What these thresholds mean for gravel
NVE's rain and snow grids
The figures come from seNorge, the national rain and snow model run by NVE, the Norwegian Water Resources and Energy Directorate, on a 1 km grid across the whole country. Linje reads the rain and temperature for where you start, and the snow depth in every grid square the route crosses, now and a week ago, so it can say where the snow is and whether it is arriving or melting.
A model puts a centimetre of notional snow on a hilltop for days after the last of it has gone, so Linje counts snow from 3 cm. Tarmac above the snowline is taken to be cleared, and Linje says that is an assumption.
Always with the date
Every reading shows when it was taken. And moving the departure time changes the answer only by the rain still forecast between now and then: what has already fallen is fixed.
Questions
How does Linje know if the gravel is wet?
It reads the rain of the last three days where your ride starts, from NVE's seNorge grid.
Where does Linje get its snow data?
From NVE's seNorge model, a 1 km grid of snow depth across Norway. Linje counts snow from 3 cm and checks every grid square the route crosses.
Sources
- NVE and the seNorge rain and snow grids: senorge.no
- The rain still to come before you set off: MET Norway's Locationforecast: api.met.no
Describes the app as of .
Related
Where are you riding next?
Linje builds the ride, then works out when to leave and which way round. Join the waitlist for early access.