=================================== Weekly Space Weather Highlights =================================== Highlights of Solar and Geomagnetic Activity 18 - 24 October 2021 Solar activity was very low. Background x-ray enhancement began on 20 Oct as new Regions 2886 (S19, L= 338, class/area Hsx/185 on 19 Oct) and 2887 (S25, L=278, class/area Dki/440 on 24 Oct) emerged around the SE limb on 17 Oct and 21 Oct, respectively. Region 2886 was quiet and stable while Region 2887 produced the majority of the B-class flare activity. The largest flare of the period was a B9.6 flare at 22/1838 UTC from a region just beyond the East limb. No Earth-directed CMEs were observed. No proton events were observed at geosynchronous orbit. The greater than 2 MeV electron flux at geosynchronous orbit was at normal to moderate levels with a peak flux of 433 pfu at 18/1700 UTC. Geomagnetic field activity ranged from quiet to active levels. The period began under the influence of a weak transient with total field reaching 13 nT and the Bz component reaching -8 nT late on 17 Oct. Solar wind speed ranged from 325-385 km/s during this time. Slightly perturbed conditions continued on 19-20 Oct as a solar sector boundary crossing followed by a co-rotating interaction region preceded the onset of a negative polarity coronal hole high speed stream (CH HSS). Solar wind speed increased to 555 km/s early on 21 Oct. Nominal solar wind conditions returned by midday on 23 Oct. The geomagnetic field responded with quiet to active levels on 18-19 Oct, quiet to unsettled conditions on 20 Oct, and quiet levels thereafter. Forecast of Solar and Geomagnetic Activity 25 October - 20 November 2021 Solar activity is expected to be at very low to low levels with a slight chance for M-class (R1-R2, Minor-Moderate) flares on 25 Oct - 03 Nov as Region 2887 transits across the visible disk. Very low levels are expected from 04 Nov -15 Nov. Very low to low levels are expected again on 16-20 Nov with the return of Region 2887. 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 throughout the forecast period. Geomagnetic field activity is expected to reach unsettled levels on 27-30 Oct, 06-08 Nov, and 15-16 Nov and active levels on 06 Nov due to CH HSS activity.