*********************************************************************** Product: Daily Forecast of Geomagnetic Activity Issued: 2019 October 21 06:30UTC Prepared by the Athens Space Weather Forecasting Center *********************************************************************** 1. Solar activity Solar activity was almost stable during the past 24 hours. Solar Flux (10.7 cm) measured on 20.10.2019 at 20:00 UTC was 65 sfu. The background X-Ray flux is at the class A6 level. The geomagnetic field was at quiet to unsettled levels on October 20. 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: 340 km/s. Solar Wind speed from STEREO A: 535 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 southern hemisphere coronal hole (CH940) was in Earth facing position on October 17-18. Unsettled conditions probably associated with this CH noticed on the last hours of Oct. 20. A new equatorial coronal hole (CH941) will be in Earth facing position on October 20-22. A high speed stream of solar wind from CH941 is expected to reach Earth on the second half of October 23. 5. Geophysical Activity Forecast The geomagnetic field is expected to be at quiet to unsettled levels with a chance for active intervals on October 21, at quiet levels on October 22 and at quiet to active levels with a chance for minor storm intervals on October 23 due to CH941 effects. Date Estimated Ap index Expected geom. storm 2019.10.21 04 - 2019.10.22 03 - 2019.10.23 10 - *************************************************************************** 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 ***************************************************************************