Space Weather Forecast Headline: Chance of G1/Minor Geomagnetic Storms day 1 and 2 (16 and 17 Sep).

Analysis of Space Weather Activity over past 24 hours

Solar Activity: Solar activity has been Very Low. There are two sunspot regions on the visible disc, both in the far west and present as mature, stable regions at this time.

There were no Earth directed Coronal Mass Ejections (CMEs) observed during the period. 

Solar Wind / Geomagnetic Activity: Solar winds indicated a mixture of overlapping coronal hole fast wind and CME effects. Speed were initially Slightly Elevated, but saw two periods of significant enhancement to Fast levels. One roughly between 15/1200-1230 UTC and a second between 15/1815-1930 UTC. Peak speeds of 788km/s were indicated at 15/1832 UTC. Otherwise, a general rise was seen from with persistently Elevated levels observed since approximately 15/2230 UTC (generally around 540km/s). It is speculated that the two periods of significantly enhanced solar winds were due to the glancing impact of the fast CME from 13 Sep, with coronal hole fast wind influence dominant overall. The Interplanetary Magnetic Field, Bt, was Moderate to Strong initially. Since 16/0330 UTC the Interplanetary Magnetic Field strength has been persistently Weak. The important north-south component, Bz, was Moderately positive (northwards) to start, reverting to generally Moderately negative (southwards) after 15/1800 UTC, then varying Weakly from around 16/0000 UTC. Geomagnetic activity was Quiet to Unsettled (Kp0-3). 

Energetic Particles / Solar Radiation: High energy proton flux was at normal background levels, with no Solar Radiation storms observed.

Four-Day Space Weather Forecast Summary

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

Solar Wind / Geomagnetic Activity: A moderately-fast CME that left the Sun on 14 Sep is expected to pass ahead of Earth orbit either late day 1 (16 Sep) or early day 2 (17 Sep), but may give a glancing impact. 

Recent increases in solar wind speeds are likely due to the connection to the fast wind of large, elongated CH94/- in the northern hemisphere. Predominantly Elevated or Strong speeds are expected through days 1 and 2 (16 and 17 Sep) before slowly declining thereafter as the high-speed stream eases.

Geomagnetic activity is expected to be mainly Quiet to Unsettled on day 1 and 2 (16 and 17 Sep), with a chance of reaching Active or G1/Minor storming levels should any potential CME arrival combine with ongoing CH effects. Days 3 and 4 (18 and 19 Sep) should see a return to persistently Quiet or Unsettled levels.

Energetic Particles / Solar Radiation: The high energy proton flux in the solar wind is at normal background levels and not expected to change significantly during the forecast period.