*********************************************************************** Product: Daily Forecast of Geomagnetic Activity Issued: 2018 June 26 05:34UTC 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 25.06.2018 at 20:00 UTC was 73 sfu. The background X-Ray flux is at the class A6 level. The geomagnetic field was at quiet to minor storm (G1) levels on June 25. No obviously Earth directed CMEs were observed in available LASCO imagery. The Kp index now is at minor storm (G1) levels with Kp=5. 2. Solar Wind Geomagnetic Activity Solar Wind speed from ACE: 415 km/s. Solar Wind speed from STEREO A: 455 km/s. Solar Wind speed from STEREO B: --- km/s. The southward component Bz is: 4 nT south. 3. Solar Energetic Particle Events Protons and electrons are quiet. 4. Coronal Holes A new coronal hole (CH871) in the southern hemisphere of the visible solar disk will be in Earth facing position on June 24-26. A high speed stream of solar wind finally reached Earth on the last hours of June 25, almost half a day earlier than our prediction, triggering a G1 geomagnetic storm. 5. Geophysical Activity Forecast The geomagnetic field is expected to be at unsettled to minor storm levels on June 26-27 and at quiet to active levels on June 28 due to CH871 effects. Date Estimated Ap index Expected geom. storm 2018.06.26 19 G1 2018.06.27 19 G1 2018.06.28 14 - *************************************************************************** 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 ***************************************************************************