*********************************************************************** Product: Daily Forecast of Geomagnetic Activity Issued: 2019 December 19 07:28UTC 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 18.12.2019 at 20:00 UTC was 70 sfu. The background X-Ray flux is at the class < A1 level. The geomagnetic field was at quiet to active levels on December 18. 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: 500 km/s. Solar Wind speed from STEREO A: --- 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 small coronal hole (CH947) on the northern hemisphere of the visible solar disk will be in Earth facing position on Dec. 14-15. A high speed stream of solar wind from this CH reached Earth on the first hours of Dec. 18 as it was predicted. 5. Geophysical Activity Forecast The geomagnetic field is expected to be at unsettled to active levels on December 19, with a chance for minor storm intervals, due to CH947 effects and at almost quiet to unsettled levels on December 20-21. Date Estimated Ap index Expected geom. storm 2019.12.19 12 - 2019.12.20 07 - 2019.12.21 05 - *************************************************************************** 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 ***************************************************************************