What happened in the original forecast window
NOAA’s planetary K index was observed at 4.0 during 00:00–03:00 UTC on October 11, below this article’s original Kp 5.67 forecast for that exact interval. This is a global geomagnetic reading, not a report of visibility in any city.
City forecast
| City | Forecast window |
|---|---|
| Iqaluit | Oct 10, 20:00–23:00 EDT (Kp 5.67) |
| Thompson | Oct 10, 19:00–22:00 CDT (Kp 5.67) |
| Fort McMurray | Oct 10, 18:00–21:00 MDT (Kp 5.67) |
Use the local time attached to your city when planning a northern lights watch.
This article’s local windows and Kp 5.67 figure are the original forecast for its specified three-hour interval.
NOAA later observed a lower planetary K index in that same interval. This global measurement does not report city visibility.
What to do
- Use the city-specific three-hour peak window.
- Check whether darkness overlaps, along with clouds and the live city forecast.
- Choose an open viewing spot away from direct lighting if conditions support a watch.
Sources and live checks
Original article figures use NOAA SWPC’s Planetary K-index forecast JSON retrieved October 10 at 19:03 UTC. NOAA’s forecast feed checked October 11 at 19:18 UTC records observed Kp 4.0 for 00:00–03:00 UTC on October 11, below the original Kp 5.67 forecast for that exact interval; this is not a city visibility report.