Highlights of Solar and Geomagnetic Activity 06 - 12 September 2021
Solar activity was at low levels with C-class activity observed from three separate regions. Region 2864 (N24, L=249, class/area Cso/120 on 07 Sep) produced a C2/Sf event at 08/0009 UTC. Associated with this flare were Type II (723 km/s shock velocity) and Type IV radio signatures, along with a weak, Earth-directed CME. Region 2866 (S18, L=199, class/area Dkc/500 on 09 Sep) produced four C-class events including the largest of the period; a C8/1n at 08/1730 UTC. Region 2868 (S21, L=213, class/area Dhi/300 on 08 Sep) also produced four C-class flares during the period.
No proton events were observed at geosynchronous orbit.
The greater than 2 MeV electron flux at geosynchronous orbit was at high levels on 06-07 Sep with a peak of 3,280 pfu observed at 06/1615 UTC. Normal to moderate levels were observed on 08-12 Sep. Geomagnetic field activity was at quiet to isolated active levels during the period. Quiet to active conditions were observed on 06-08 Sep due to weak, positive polarity CH HSS influence. Quiet levels were observed on 09 Sep through a majority of 10 Sep. Unsettled to active conditions were observed on late 10 Sep through early on 11 Sep due to weak influence from the 08 Sep CME. Quiet conditions were observed for the remainder of 11 Sep through 12 Sep.
Forecast of Solar and Geomagnetic Activity 13 September - 09 October 2021
Solar activity is expected to be at low levels, with a slight chance for M-class activity, on 13-16 Sep due to potential flare activity from Regions 2866 and 2868. Very low to low activity is expected from 17-28 Sep. A return to low levels, with a slight chance for M-class activity, is possible on 29 Sep - 09 Oct upon the return of old Regions 2866 and 2868.
No proton events are expected at geosynchronous orbit.
The greater than 2 MeV electron flux at geosynchronous orbit is expected to be at normal to moderate levels on 13 Sep - 04 Oct and 08-09 Oct. Moderate to high levels are possible on 05-07 Oct due to CH HSS influence.
Geomagnetic field activity is expected to be at unsettled levels on 21 Sep and unsettled to active levels on 04-05 Oct, all due to positive polarity CH HSS influence. The remainder of the outlook period is expected to be at mostly quiet levels.
Product: 27-day Space Weather Outlook Table 27DO.txt
:Issued: 2021 Sep 13 0136 UTC
# Prepared by the US Dept. of Commerce, NOAA, Space Weather Prediction Center