*********************************************************************** Product: Daily Forecast of Geomagnetic Activity Issued: 2018 August 18 04:26UTC Prepared by the Athens Space Weather Forecasting Center *********************************************************************** 1. Solar activity Solar activity was increasing during the past 24 hours. Solar Flux (10.7 cm) measured on 17.08.2018 at 20:00 UTC was 67 sfu. The background X-Ray flux is at the class A2 level. The geomagnetic field was at quiet to active levels on August 17. No obviously Earth directed CMEs were observed in available LASCO imagery. The Kp index now is at almost quiet levels with Kp=2. 2. Solar Wind Geomagnetic Activity Solar Wind speed from ACE: 540 km/s. Solar Wind speed from STEREO A: 370 km/s. Solar Wind speed from STEREO B: --- km/s. The southward component Bz is: 3 nT south. 3. Solar Energetic Particle Events Protons and electrons are quiet. 4. Coronal Holes A new coronal hole (CH881) is expected to be in Earth facing position on August 16-19. A high speed stream of solar wind is expected to reach Earth on the second half of August 20. 5. Geophysical Activity Forecast The geomagnetic field is expected to be at very quiet levels, with a chance for unsettled intervals, on August 18-19 and at very quiet to active levels on August 20 due to CH881 effects. Date Estimated Ap index Expected geom. storm 2018.08.18 03 - 2018.08.19 02 - 2018.08.20 10 - *************************************************************************** Athens Space Weather Forecasting Center Physics Department, National & Kapodistrian University of Athens Athens Neutron Monitor Station A.NE.MO.S Tel.: +30 210 727 6901 email: spaceweather@phys.uoa.gr URL: http://spaceweather.phys.uoa.gr ***************************************************************************