Thank you so much for the quick reply!
We will be near Churchill August 5-11. I'm sorry to say I'm still kind of confused.
The key shows that some of the brighter green colors indicate 50% probability of visible auroras, but the hemispheric power chart says below 20GW indicates little of no probability of a visible aurora. So, for example, at 5:45pm UTC (right about now), the hemispheric power charts shows 12GW, which would indicate little or no probability of a visible aurora, but the map shows some fairly bright green in some parts of the auroral oval. Can you help me understand how those two measures square?
By the way, if you have time for a specific question, I would be curious to know whether you think we are likely to see any aurora near Churchill August 5-11. Would auroras be common there even in this time of solar minimum? In your judgment, what sort of indicators on the geographical map and/or on the hemispheric power chart would we need to see in order to make it worthwhile for us to wake up to watch for auroras during the short times of darkness that week?
Thank you very much for your help!