*********************************************************************** Product: Daily Forecast of Geomagnetic Activity Issued: 2018 May 18 05:20UTC 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 17.05.2018 at 20:00 UTC was 69 sfu. The background X-Ray flux is at the class A2 level. The geomagnetic field was at almost quiet to unsettled on May 17. 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: 440 km/s. Solar Wind speed from STEREO A: 320 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 A coronal hole (CH864) in the southern hemisphere of the visible solar disk was in Earth facing position on May 13-15. The associated high speed stream of solar wind reached Earth at the last hours of May 16 as it was predicted. A new coronal hole (CH865) which is an extension of the northern polar coronal hole will be in Earth facing position on May 18-19. 5. Geophysical Activity Forecast The geomagnetic field is expected to be at quiet to unsettled levels on May 18 and at almost quiet levels on May 19-20. Date Estimated Ap index Expected geom. storm 2018.05.18 07 - 2018.05.19 06 - 2018.05.20 05 - *************************************************************************** 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 ***************************************************************************