*********************************************************************** Product: Daily Forecast of Geomagnetic Activity Issued: 2018 July 24 05:55UTC Prepared by the Athens Space Weather Forecasting Center *********************************************************************** 1. Solar activity Solar activity was decreasing stable during the past 24 hours. Solar Flux (10.7 cm) measured on 23.07.2018 at 20:00 UTC was 67 sfu. The background X-Ray flux is at the class A1 level. The geomagnetic field was at very quiet levels on July 23. No obviously Earth directed CMEs were observed in available LASCO imagery. The Kp index now is at active levels with Kp=4. 2. Solar Wind Geomagnetic Activity Solar Wind speed from ACE: 480 km/s. Solar Wind speed from STEREO A: 450 km/s. Solar Wind speed from STEREO B: --- km/s. The southward component Bz is: 4 nT north. 3. Solar Energetic Particle Events Protons and electrons are quiet. 4. Coronal Holes A new coronal hole (CH876) on the southern hemisphere of the visible solar disk will be in Earth facing position on July 21-22. A high speed stream of solar wind from CH876 finally reached Earth on the first hours of July 24 as it was predicted. 5. Geophysical Activity Forecast The geomagnetic field is expected to be at quiet to active levels with a chance for minor storm intervals on July 24-25 and at quiet to unsettled levels on July 26. Date Estimated Ap index Expected geom. storm 2018.07.24 17 G1 2018.07.25 14 - 2018.07.26 09 - *************************************************************************** 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 ***************************************************************************