Space Weather Forecast Headline: Chance of G1/Minor Geomagnetic Storms days 1 and 2.

Analysis of Space Weather Activity over past 24 hours

Solar Activity: Solar activity has been Low, with a peak flare recorded at 13/1944 UTC, reaching C1.41 from a filament eruption in south centre disk. There are four sunspot regions on the visible disc, all of which reside in the western hemisphere. A region in the northwest is marginally the most complex region on the disk. It has a beta magnetic configuration, but it's spots seems to be fading. All other regions are small or moderately sized but magnetically simple and stable.

A faint but fast Coronal Mass Ejection was observed in LASCO imagery late on 13 Sep, likely associated with the aforementioned filament eruption and C1.41 flare, though analysis was difficult due to lack of triangulating imagery from STEREO, and the Coronal Mass Ejection appears to have been deflected west. 

Solar Wind / Geomagnetic Activity: Solar winds, as measured by L1 by SOLAR-1, indicated a possible weak coronal hole fast winds between 13/1250-2040 UTC, with slightly elevated solar winds at that time.  Since then solar wind speeds have been background at 280-350km/s. The interplanetary magnetic field, Bt, was weak and has risen to moderate from 14/1100 UTC. The north-south component, Bz, was weak and varying. Geomagnetic activity was Quiet (Kp 1-2). 

Energetic Particles / Solar Radiation: GOES18 >10MeV proton flux was at 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: The weak enhancement to the solar winds on afternoon of 13 Sept may be attributed to a coronal hole and although this was more muted than expected this could continue to have some effects on Day 1 (14 Sept). The CME from 9 Sept arrived around 14/0240 UTC and again had little effect on the solar winds or geomagnetic activity but some effects from this on Day 1 are possible. The next enhancement, from another coronal hole, is expected to be more considerable. It is slightly larger and further west than the previous rotation. Connection to the fast winds is likely late on Day 2 or early Day 3 (15-16 Sept).  Solar winds of around 600km/s were observed at L1 previously and it is considered likely that similarly Strong speeds will be observed between Days 2 and 3 (15-16 Sep), before gradually easing back to Slightly Elevated levels by Day 4 (17 Sep). There is also the chance of a glancing blow from a CME originating from a filament eruption on 13 Sept, which may arrive early on Day 3 (16 Sept), though there is uncertainty with regards the timing.

Geomagnetic activity is expected to be Quiet to Unsettled (Kp0-3) initially. There is then a chance of Active to G1/Minor storms (Kp4-5) at times later on day 1 and on day 2 (14-15 Sep) due to combined Coronal Mass Ejection and multiple coronal hole fast wind effects. From day 3 onward (16-17) mostly Quiet to Unsettled conditions should return as the fast winds wane.

Energetic Particles / Solar Radiation: GOES18 >10MeV proton flux is at background with no Solar Radiation storms expected.