Data sources & methods
Understand the evidence behind the outlook.
NOAA SWPC
Current Kp is a near-real-time estimate of global geomagnetic activity. The Kp forecast covers three-hour intervals. OVATION is a short-term aurora model with its own forecast timestamp, not an observation of visible aurora. The site does not turn model intensities into personal visibility probabilities.
Weather from NOAA NWS and MET Norway
Total cloud forecasts use the NOAA National Weather Service skyCover grid at each location. Grid values apply to their stated validity intervals; displaying them hourly does not make the model more precise. Temperature and wind use available NWS values, with MET Norway supplying cloud layers and weather fallback. These are different forecast models and are not blended into a single cloud percentage. Neither active weather integration provides usable visibility here, so it is shown as unavailable rather than estimated. Data is licensed under NLOD 2.0 / CC BY 4.0; temperatures and winds are converted to °F and mph. Credit: data from the Norwegian Meteorological Institute (MET Norway).
Caching, uncertainty and outages
Requests are deduplicated and cached for ten minutes per running server instance. Previously fetched weather may be retained up to three hours with its original timestamp. Missing or expired essential forecasts produce Not Enough Data. This is not a durable shared cache and does not guarantee availability during traffic spikes.
Planning method
The existing custom heuristic combines Kp, eligible near-term OVATION data, modeled clouds, solar altitude and moonlight. It is a score, not a validated probability. Anchorage outlook and viewing window use Anchorage inputs; alternative locations use their own weather. Cloud forecast differences are model comparisons, not live confirmation.
Other references
UAF is an authoritative educational reference only; we do not scrape its forecast. OpenStreetMap supplies optional map tiles and requires attribution and compliant usage; large traffic may require a commercial tile service. Open-Meteo’s noncommercial free hosted integration has been removed. SunCalc provides astronomy calculations.