*********************************************************************** Product: Daily Forecast of Geomagnetic Activity Issued: 2019 September 23 05:37UTC 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 22.09.2019 at 20:00 UTC was 68 sfu. The background X-Ray flux is at the class A6 level. The geomagnetic field was at quiet levels on September 22. No obviously Earth directed CMEs were observed in available LASCO imagery. The Kp index now is at very quiet levels with Kp=0. 2. Solar Wind Geomagnetic Activity Solar Wind speed from ACE: 300 km/s. Solar Wind speed from STEREO A: 550 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 equatorial coronal hole (CH937) was in Earth facing position on 20-21 September. An associated high speed stream of solar wind is expected to reach Earth on the second half of September 23. A new equatorial coronal hole (CH938) will be in Earth facing position on September 24-25. 5. Geophysical Activity Forecast The geomagnetic field is expected to be at quiet to unsettled levels on September 23-25 with a chance for active intervals due to CH937 effects. Date Estimated Ap index Expected geom. storm 2019.09.23 08 - 2019.09.24 12 - 2019.09.25 11 - *************************************************************************** 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 ***************************************************************************