=================================== Weekly Space Weather Highlights =================================== Highlights of Solar and Geomagnetic Activity 13 - 19 August 2018 Solar activity was very low. Two small regions developed on the visible disk this period. Region 2718 (S07, L=191, class/area Hrx/020 on 17 Aug) developed on 14 Aug and decayed to plage by 19 Aug. Region 2719 (S06, L=133, class/area Bxo/010 on 19 Aug) developed in the SE quadrant on 19 Aug. No significant flare events occurred from either region. Other activity included a filament eruption centered near S11W04 observed lifting off the solar disk at approximately 19/0538 UTC. An associated coronal mass ejection was observed off the SW limb in SOHO/LASCO C2 imagery at 19/0812 UTC. WSA/Enlil modelling of the event suggested the ejecta was primarily directed westward of the Sun-Earth line and is not expected to cause any significant effects. No proton events were observed at geosynchronous orbit. The greater than 2 MeV electron flux at geosynchronous orbit was at normal levels on 13-15 Aug, moderate levels on 16-17 Aug, and at high levels on 18-19 Aug. The largest flux of the period was 18,287 pfu observed at 19/1800 UTC. Geomagnetic field activity ranged from quiet to active levels over the period. Solar wind speed was at nominal levels at the beginning of the period with solar wind speed ranging from 310-430 km/s while total field was between 1-4 nT. The geomagnetic field was quiet on 13-14 Aug. By 15 Aug, solar wind speed increased to approximately 450-500 km/s with total field increasing to a maximum of 14 nT by 16/1005 UTC as a positive polarity coronal hole high speed stream (CH HSS) moved into geoeffective position. A further increase in solar wind speed to near 570 km/s was observed late on 17 Aug before slowly receding to nominal levels by midday on 19 Aug. The geomagnetic field responded with quiet to active levels on 15-18 Aug. By late on 19 Aug, total field increase again to 12 nT along with an increase in solar wind to near 550 km/s as a negative polarity CH HSS was becoming geoeffective. However, only quiet levels were observed on 19 Aug. Forecast of Solar and Geomagnetic Activity 20 August - 15 September 2018 Solar activity is expected to continue at very low levels. No proton events are expected at geosynchronous orbit. The greater than 2 MeV electron flux at geosynchronous orbit is expected to reach high levels on 22-27 Aug and again on 13-15 Sep due to CH HSS influence. Geomagnetic field activity is expected to be unsettled to active levels on 20-25 Aug, 03-04 Sep, 07 Sep, and 11-15 Sep with a chance for G1 (Minor) geomagnetic storm levels on 20-21 Aug due to recurrent CH HSS activity.