*********************************************************************** Product: Daily Forecast of Geomagnetic Activity Issued: 2018 July 18 05:42UTC 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 17.07.2018 at 20:00 UTC was 71 sfu. The background X-Ray flux is at the class A3 level. The geomagnetic field was at quiet to unsettled levels on July 17. No obviously Earth directed CMEs were observed in available LASCO imagery. The Kp index now is at quiet levels with Kp=1. 2. Solar Wind Geomagnetic Activity Solar Wind speed from ACE: 420 km/s. Solar Wind speed from STEREO A: 570 km/s. Solar Wind speed from STEREO B: --- km/s. The southward component Bz is: 0 nT. 3. Solar Energetic Particle Events Protons and electrons are quiet. 4. Coronal Holes An extension of the northern polar coronal hole (CH875) will be in Earth facing position on July 15-16. A high speed stream of solar wind from CH875 is expected to reach Earth on the first half of July 19. 5. Geophysical Activity Forecast The geomagnetic field is expected to be at very quiet levels on July 18 and at quiet to active levels on July 19-20 due to CH875 effects. Date Estimated Ap index Expected geom. storm 2018.07.18 03 - 2018.07.19 10 - 2018.07.20 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 ***************************************************************************