Bz is the number that matters. Everything else can look promising and still produce nothing if the field stays north — a strong wind with Bz at +5 is a quiet night, and a modest wind with Bz at −10 will put a band overhead within the hour.
Approximate southern limit of the auroral oval at local midnight. From here that means Kp 4 shows a glow low on the northern horizon, Kp 5 puts structure in it, and anything at 6 or above is worth waking someone up for.
Bz flipped south around eleven and held for about forty minutes. One good breakup — rays reaching maybe thirty degrees, green with a faint purple edge at the top. Gone by half past midnight and it did not come back.
Wind speed up over 600 km/s for most of the night but the field stayed variable. Steady band on the horizon for hours without ever lifting. The sort of night that looks much better in a long exposure than it does standing there.
Kp forecast at 5, actual peak 3. Clear sky, cold, three hours outside for a flat horizon. Logged because the misses are the more useful half of the record.
Readings pulled from the public solar wind feed every fifteen minutes and written down by hand at the start and end of each watch. No camera — the notes describe what was visible to a dark-adapted eye, which is a much lower bar than a twenty second exposure clears.
The horizon to the north is open across a field, which is most of why anything gets seen at this latitude at all.