Space Weather Forecast Headline: Likely G1/Minor with chance G2/Moderate and slight chance of G3/Strong day 1, lowering risk into day 2. 

Analysis of Space Weather Activity over past 24 hours

Solar Activity: Solar activity has been Very Low. There are three sunspot regions on the visible disc, all of which are relatively small, stable, and magnetically simple. 

There were no Earth directed CMEs (coronal mass ejections) observed during this period. 

Solar Wind / Geomagnetic Activity: Solar winds indicated weak fast wind and possible CME effects initially, until later in the period, at which point a stronger connection to a fast wind high speed stream (HSS) looks to have occurred. Solar wind speeds were mainly Background between 300-400km/s until around 15/0914UTC, at which point they became Slightly Elevated. Speeds then showed a sharp increase around midday UTC, and then again around 15/1820UTC, with similar Strong peaks of around 800km/s. The interplanetary magnetic field was generally Moderate throughout, but did infrequently become Strong. The north-south component was Weak to Moderate, generally positive for much of the period, but did become more consistently negative after 15/1820UTC. Geomagnetic activity was Quiet to Unsettled (Kp0-3). 

Energetic Particles / Solar Radiation: Proton flux was initially enhanced (but below the S1 threshold), and has subsequently fallen to Background levels. 

Four-Day Space Weather Forecast Summary

Solar Activity: Solar activity is expected to remain Low or Very Low with only a slight chance of reaching Moderate levels should any isolated Moderate-class flares occur.

Solar Wind / Geomagnetic Activity: Two coronal mass ejections feature in the forecast, both filament eruptions from the southwest quadrant, one from 13 Sep and another from 14 Sep. Both bring a chance of arrival early and late on day 1 (16 Sep) respectively, with glancing impacts most likely. 

The recent increases in solar wind speeds is likely due to the Earth skirting along the southern edge of a northerly positioned high speed stream. Similar increases, and subsequent decreases, in wind speeds are possible through days 1-2 (16-17 Sep), and along with any CME arrivals could see periods of Strong wind speeds and increased geomagnetic activity. Wind speeds are then expected to decline back to more background levels from day 3 (18 Sep).

Geomagnetic activity is expected to be mostly Quiet to Active (Kp2-4) on day 1 (16 Sep), with a likelihood of G1/Minor (Kp5), Chance of G2/Moderate (Kp6) and slight chance of G3/Strong (Kp7) storming should any CME arrivals combine with ongoing fast wind effects. Day 2 (17 Sep) may see lingering fast wind effects and perhaps residual CME effects with a chance of G1/Minor (Kp5) and a slight chance of isolated G2/Moderate (Kp6) intervals. Days 3 and 4 (18-19 Sep) should see a return to largely Quiet to Unsettled (Kp0-3).

Energetic Particles / Solar Radiation: Proton flux has returned to background levels following a recent enhancement. Further enhancements are considered unlikely due to the lack of complexity on the disc, but there is a slight chance of seeing some slight proton enhancement ahead of the possible glancing CMEs expected on day 1 (16 Sep).