Diary

A short-lived increase in geomagnetic activity, lasting 10–15 hours, is expected tonight, from October 19 to 20. Calculations indicate that Earth will be grazed by a dense stream of solar wind originating from a large coronal hole currently visible on the Sun’s disk. This coronal hole appears in space-based imagery as a dark region in the solar corona, stretching approximately one million kilometers from the Sun’s south pole nearly to its equator. Given its current orientation, the fastest and densest streams of material from this region should pass below the plane of the planets' orbits. A few days ago, it seemed likely that the high-speed solar wind would miss the planetary plane entirely; however, current mathematical estimates suggest that Earth will be clipped by its outer edge.

The event is expected to be minor—something that, during the peak of a solar cycle, might not even warrant a mention. Yet, now that the solar peak has passed and the Sun is in a relatively quiet, "smoldering" state, this event becomes quite noticeable. There is roughly a 50% chance that the disturbances will escalate beyond a simple "yellow-level" alert, potentially intensifying into a minor geomagnetic storm over the course of today and tomorrow. Since the event is occurring at night, conditions may be favorable for observing auroras across the European part of Russia—provided, of course, that there is actually something to see; for now, all of the above remains strictly preliminary.

As of this writing, there are no signs that Earth has entered the plasma stream from the coronal hole. According to forecasts, the density of the solar wind is expected to begin increasing within the next few hours.

Solar flare activity remains at a moderately elevated level. There is a fairly high probability of M-class flares, but at the same time, no direct threats to Earth are apparent. It is believed that the star currently lacks the energy required for truly powerful flares.