*********************************************************************** Product: Daily Forecast of Geomagnetic Activity Issued: 2018 September 17 06:10UTC 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 16.09.2018 at 20:00 UTC was 69 sfu. The background X-Ray flux is at the class A2 level. The geomagnetic field was at very quiet levels on September 16. 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: 500 km/s. Solar Wind speed from STEREO A: 320 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 coronal hole (CH885) was in Earth facing position on September 13-14. A high speed stream of solar wind is expected to reach Earth on the first hours of September 17. 5. Geophysical Activity Forecast The geomagnetic field is expected to be at quiet to active levels on September 17 and at quiet to unsettled levels on September 18 due to CH885 effects. Quiet conditions are expected on September 19. Date Estimated Ap index Expected geom. storm 2018.09.17 14 - 2018.09.18 07 - 2018.09.19 04 - *************************************************************************** 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 ***************************************************************************