*********************************************************************** Product: Daily Forecast of Geomagnetic Activity Issued: 2018 December 17 05:30UTC 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 16.12.2018 at 20:00 UTC was 70 sfu. The background X-Ray flux is at the class A3 level. The geomagnetic field was at very quiet levels on December 16. 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: 350 km/s. Solar Wind speed from STEREO A: 330 km/s. Solar Wind speed from STEREO B: --- km/s. The southward component Bz is: 1 nT north. 3. Solar Energetic Particle Events Protons and electrons are quiet. 4. Coronal Holes A new coronal hole (CH900) which is an extension of the southern polar coronal hole was in Earth facing position on December 12-13. 5. Geophysical Activity Forecast The geomagnetic field is expected to be at very quiet levels, with a chance for unsettled intervals due to CH900 effects, on December 17-19. Date Estimated Ap index Expected geom. storm 2018.12.17 03 - 2018.12.18 02 - 2018.12.19 01 - *************************************************************************** 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 ***************************************************************************