Space Weather Forecast Headline: CME arrival expected to bring G1-G2/Minor-Moderate Geomagnetic storming, with a chance of G3/Strong Geomagnetic storming Day 1 (05 Jun). Likelihood of isolated Moderate solar flares continues.

Analysis of Space Weather Activity over past 24 hours

Solar Activity: Solar activity is Low over the past 24 hours. 

There are currently seven sunspot regions visible on the solar disc. AR4455, located in the northwest disc, remains a complex active region, retaining several small negative-polarity spots, arranged in an arc around its dominant positive-polarity spot, although for now development appears to have slowed. The disk has seen a general increase in growth over recent hours, with AR4459 and AR4457 continue to develop, and an increasingly complex magnetic structure visible for AR4459. Meanwhile in the far east, AR4461 and AR4462 are relatively simple magnetically.

No significant Earth-directed Coronal Mass Ejections (CMEs) were preliminarily observed in available imagery. Although analysis of imagery is ongoing.

Solar Wind / Geomagnetic Activity: Solar winds were mainly Slightly Elevated, peaking around 465km/s. The Interplanetary Magnetic Field, Bt, initially Weak to Moderate, declined into the period to Weak levels following the clearance of what appears to be a weak transient feature. The important north-south component, Bz, was Weak to Moderate. Geomagnetic activity was Quiet to Unsettled (Kp1-3).

Energetic Particles / Solar Radiation: Solar radiation levels were at Background.

Four-Day Space Weather Forecast Summary

Solar Activity: Solar activity is expected to be Low to Moderate, with a continued likelihood of isolated Moderate solar flares from a number of sunspot regions. There is a slight chance of High Solar activity given the risk of an isolated Strong solar flare, this most likely from sunspot region AR4455 in the near term given the history of the region.

Solar Wind / Geomagnetic Activity: Three potentially Earth-directed CMEs are present in the forecast, all associated with solar flares from sunspot region AR4455. Influence from these features is expected during Day 1 (05 June) with impacts persisting through into Day 2 (06 June) before likely declining. Some enhancement to the solar wind is also expected from from a stream of faster solar winds through Day 1 into Day 2 (05-06 June). Activity is expected to decline into Day 3 (07 June) as CME impacts wane; solar winds potentially returning towards background levels by Day 4 (08 June) in the absence of further CME activity. 

Overall geomagnetic activity is expected to increase sharply early on Day 1 (05 June), with G1–G2 (Minor to Moderate) geomagnetic storm conditions (Kp 5–6) expected, a chance of G3 (Strong) storm intervals (Kp 7), and a slight chance of isolated G4 (Severe) geomagnetic storm intervals depending on CME arrival character.  Activity likely to ease on Day 2 (06 June), however confidence is reduced due to the complex influence of the second and third CMEs, which could sustain elevated geomagnetic conditions. A more substantial decline in activity is currently considered most likely on Days 3 and 4 (07 and 08 June).

Energetic Particles / Solar Radiation: Solar Radiation counts are at Background and expected to remain so through the period.