*********************************************************************** Product: Daily Forecast of Geomagnetic Activity Issued: 2018 September 23 07:10UTC 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 22.09.2018 at 20:00 UTC was 68 sfu. The background X-Ray flux is at the class A2 level. The geomagnetic field was at unsettled to minor storm levels on September 22. No obviously Earth directed CMEs were observed in available LASCO imagery. The Kp index now is at unsettled levels with Kp=3. 2. Solar Wind Geomagnetic Activity Solar Wind speed from ACE: 440 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 south. 3. Solar Energetic Particle Events Protons and electrons are quiet. 4. Coronal Holes An equatorial coronal hole (CH887) was in Earth facing position on September 19-21. A high speed stream of solar wind arrived on the second half of September 21. 5. Geophysical Activity Forecast The geomagnetic field is expected to be at quiet to active levels, with a chance for minor storm intervals, on September 23 due to CH887 effects and at quiet to unsettled levels on September 24-25. Date Estimated Ap index Expected geom. storm 2018.09.23 14 - 2018.09.24 10 - 2018.09.25 07 - *************************************************************************** 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 ***************************************************************************