*********************************************************************** Product: Daily Forecast of Geomagnetic Activity Issued: 2018 April 19 06:45UTC 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 18.04.2018 at 20:00 UTC was 71 sfu. The background X-Ray flux is at the class A4 level. The geomagnetic field was at very quiet levels on April 18. 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: 290 km/s. Solar Wind speed from STEREO A: 460 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 A new equatorial coronal hole (CH861) was in Earth facing position on April 16-18. A high speed stream of solar wind is expected to reach Earth in the first hours of April 20. 5. Geophysical Activity Forecast The geomagnetic field is expected to be at quiet to unsettled levels on April 19, at quiet to active levels on April 20 and at quiet to unsettled levels on April 21 due to CH861 effects. Date Estimated Ap index Expected geom. storm 2018.04.19 05 - 2018.04.20 12 - 2018.04.21 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 ***************************************************************************