How TotalityTrip ranks eclipse bases
The score is intentionally simple, reproducible and honest about what we do not know yet.
1. Eclipse geometry
We use the NASA GSFC path table for the total solar eclipse of August 2, 2027. NASA publishes the northern limit, southern limit and central line at 120-second intervals, together with central-line duration, path width, solar altitude and azimuth.
For each trip base we store the nearest relevant central-line row as a regional benchmark. We do not label that figure as the exact duration at the city.
2. Climate outlook
Our long-range climate labels are editorial planning tiers informed by published eclipse climatology and EUMETSAT/CM SAF cloud-climate products. They are deliberately qualitative: Exceptional, Very good, Good or Variable. A label is not a percentage probability and is not a forecast for eclipse day.
3. Planner score
The default score blends the climate tier with normalized central-line duration. Users can switch the weighting toward clear-sky climatology or toward duration. The score is only used to rank our shortlist; it has no scientific probability meaning.
4. What changes close to the eclipse
Near the event, short-range cloud forecasts should dominate the decision. The production build uses MET Norway Locationforecast through a cached Cloudflare Worker. MET Norway permits commercial use of its open weather data subject to attribution and service-usage rules; the site does not depend on Open-Meteo’s non-commercial free hosted endpoint.
5. Data freshness
Current methodology reviewed September 12, 2026. NASA's eclipse geometry is stable apart from small refinements such as lunar-limb corrections. Travel conditions, local access rules and weather are not stable and must be checked again before travel.
Short-range forecast layer
The live-weather module is deliberately separate from the long-range climate score. When August 2 enters MET Norway's Locationforecast horizon, the site displays model cloud cover, air temperature, wind and precipitation near the relevant NASA benchmark time. This does not retroactively change the climate tier and is not presented as a probability of success.
Why the two layers stay separate
Climatology answers “which region is usually more favorable?” while a weather forecast answers “what is the atmosphere currently expected to do on a particular day?” Mixing the two into one opaque percentage would create false precision.