*********************************************************************** Product: Daily Forecast of Geomagnetic Activity Issued: 2019 September 21 07:18UTC 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 20.09.2019 at 20:00 UTC was 67 sfu. The background X-Ray flux is at the class A7 level. The geomagnetic field was at quiet levels on September 20. No obviously Earth directed CMEs were observed in available LASCO imagery. The Kp index now is at almost quiet levels with Kp=2. 2. Solar Wind Geomagnetic Activity Solar Wind speed from ACE: 345 km/s. Solar Wind speed from STEREO A: 370 km/s. Solar Wind speed from STEREO B: --- km/s. The southward component Bz is: 5 nT south. 3. Solar Energetic Particle Events Protons and electrons are quiet. 4. Coronal Holes A new equatorial coronal hole (CH937) will be in Earth facing position on 20 September. An associated high speed stream of solar wind is expected to reach Earth on the second half of September 23. 5. Geophysical Activity Forecast The geomagnetic field is expected to be at quiet levels on September 21-22 and at quiet to unsettled levels on September 23. Date Estimated Ap index Expected geom. storm 2019.09.21 05 - 2019.09.22 04 - 2019.09.23 12 - *************************************************************************** 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 ***************************************************************************