Redtail MudCast answers one question — has it rained on the trails, and roughly how much — for the Leon Creek / Bamberger network and McAllister Park in north-west San Antonio.
Where the numbers come from
- Personal weather stations. Every station within the map's area that reports publicly to the Ambient Weather Network is pulled in — typically 160–170 of them on a given minute. No API key, no scraping, no interpolation beyond what you see.
- Stations get checked before they count. Anything that has stopped reporting, returns an empty payload, reports an impossible rate, or duplicates another station is dropped. The map usually discards 60–90 of the raw stations on every run — a station that is down is worse than no station.
- Trails come from OpenStreetMap. Every way tagged
path,trackorcyclewaywithin 6 km of the Leon Creek / Bamberger trailhead and 3.2 km of McAllister Park. - Each trail is sampled every ~200 m. At each sample point the three nearest live stations are weighted by distance (inverse-distance weighting) to estimate the rain there. A trail is scored on the mean of its samples.
What the colours mean
Accumulation over the period shown, in inches:
- Trace≥ 0.01
- Light≥ 0.10
- Steady≥ 0.25
- Wet≥ 0.50
- Soaked≥ 1.00
- Dry< 0.01
- No datano gauge within 3 km
Average Condition in the panel is the mean of every trail's value, mapped back onto those same bands — so the headline can never disagree with the colours on the map.
What it cannot tell you
Rain is estimated from point measurements, not measured on the trail. A gauge 2 km away can easily miss a summer cell that soaked one drainage and left the next one dry. Treat a green or amber trail as "probably damp", not "definitely rideable".
No gauge within 3 km means no estimate — the map refuses to interpolate further and shows the trail dashed instead of guessing.
It also says nothing about soil, roots, or how much traffic a trail has taken. A trail that reads Dry after three sunny days can still hold water in the low, shaded turns. Use it to decide whether to drive out, then believe your tyres.
How fresh it is
The page itself is static and never needs redeploying. The numbers live in a small data document that is refreshed on a schedule and re-fetched each time you load the page; the panel shows exactly when it was last generated, in Central time. If the timestamp is old, the pipeline is not running — the map is not pretending otherwise.
Credits
Weather data: the station owners who publish to the Ambient Weather Network. Trail geometry: OpenStreetMap contributors. Basemap: Esri World Topo. Hawk silhouette from Wikimedia Commons (CC BY-SA 3.0); rider icon by Delapouite via game-icons.net (CC BY 3.0).