Space weather today

The week ahead

Unsettled. That's the whole week in one word. Not stormy, not flat calm. The Sun is muttering rather than shouting.

Monday and Tuesday look sleepy, with the Kp index topping out near 2. Wednesday is where the needle twitches: NOAA's outlook puts the largest Kp at 4, enough to stir Earth's magnetic field without crossing into storm territory. Thursday settles to 3, and Friday through Sunday drop back to 2. No geomagnetic storm is forecast on any day this week.

Underneath that, the Sun stays middling-busy. Solar radio flux hovers around 135 early on and eases to 130 by Sunday, and there's a chance of M-class flares from the complex sunspot groups on the disk. No odds are attached to any particular day, so file that under possible rather than expected.

What it means for you

• Heart & sleep: Some people track their rough nights against the Sun's rough days, and this week hands them very little to track.
• Mood & focus: If Wednesday feels foggy, a Kp of 4 is far too small to carry the blame, so check your calendar first.
• Preppers, radio & GPS: Midweek is the only stretch worth a glance if you lean on HF radio or precision GPS, and even then it's a note, not an action item.
• Aurora-chasers & the spiritually curious: With Kp peaking near 4 and no storm in the forecast, aurora stays a high-latitude affair — Alaska, northern Canada, Scandinavia, clear skies required.

Last week on the Sun

Last week ran unsettled too. The Kp index peaked at 4.67 around midday on Sunday, July 12. Active, yes, but the week recorded zero storm periods across 58 readings.

The loudest event was an M4.01 flare out of a large, complex sunspot group, and its ejecta weren't aimed at us. A separate, milder cloud from a different region did drift past Earth around the 12th, which lines up neatly with that Kp peak. (Sometimes the Sun's biggest bang and its biggest effect on you come from two entirely different addresses.)

The thing to watch right now is crowding. Several complex sunspot groups are working their way across the visible disk, and more significantly complex ones are rotating back around from the far side. That's why a chance of M-class flares keeps showing up in NOAA's outlook even on a week expected to stay low-key. Last week's geomagnetic action, though, came from quieter machinery: a high-speed stream of solar wind pouring out of a coronal hole, plus that one mild cloud arriving on the 12th. Coronal holes never get the headlines. They do most of the work.

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Forecast data: NOAA SWPC