Space Weather Forecast Headline: Chance of isolated Moderate-class solar flares. Chance of G1/Minor storm intervals Days 1, 3 and 4 (13, 15 and 16 May).

Analysis of Space Weather Activity over past 24 hours

Solar Activity: Solar Activity was Low, with only minor Common-class flaring observed. The peak flare was C2.3 at 13/0640 UTC. There are five sunspot regions on the visible disc. These are all relatively magnetically simple, and either stable or reducing in size. There is a large bipolar region in the northwest which has started to rotate off the western limb, with part of this region no longer visible in the imagery. This makes it difficult to analyse. The region in the southwest has started to reduce in size with the penumbra fading recently. The region  in the northeast, retains a pair of leading spots but has shown no signs of recent growth. All other regions are small and simple.  

No Earth-directed Coronal Mass Ejections (CMEs) were observed in the past 24hrs.

Solar Wind / Geomagnetic Activity: Solar wind speeds, as observed by ACE and DSCOVR at L1 have recently increased from background levels to Slightly Elevated at 410-420km/s.  Interplanetary Magnetic Field, Bt, has been generally Weak but on an upward trend becoming Moderate from around 13/0800 UTC. The north-south component, Bz, was Weak and variable, but has recently become Moderate. Geomagnetic activity was Quiet (Kp 0-1). Together this suggests that we are now feeling the effects of the weak glancing blow from the CME that we have been expecting.

Energetic Particles / Solar Radiation: GOES18 high energy (>10 MeV) proton flux was at Background. 

Four-Day Space Weather Forecast Summary

Solar Activity: Solar activity is forecast to remain generally Low, but with a chance of isolated Moderate-class flares, and a slight chance of isolated Strong flares. 

Solar Wind / Geomagnetic Activity: A large, fast CME followed the 10 May M5.7 flare from a sunspot region in the northeast. Modelling indicates a potential Earth-directed component with a possible arrival on 13 May. The next fast wind enhancement is predicted to affect Earth through Day 3 (15 May).

Geomagnetic activity is expected to be mainly Quiet to Unsettled on Day 1 (13 May), with the possibility of a glancing blow from a CME, which brings a chance of Active to G1/minor storm conditions (Kp 4–5). Activity is then expected to return to Quiet to Unsettled levels until the onset of fast solar winds on Day 3 (15 May). At that point, geomagnetic activity is likely to increase again, with a chance of G1/minor storm (Kp 5) intervals developing.

Energetic Particles / Solar Radiation: GOES18 high energy (>10 MeV) proton flux is expected to remain at Background levels, with no solar radiation storms expected.