*********************************************************************** Product: Daily Forecast of Geomagnetic Activity Issued: 2018 March 21 06:40UTC 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 20.03.2018 at 20:00 UTC was 69 sfu. The background X-Ray flux is at the class A2 level. The geomagnetic field was at quiet to unsettled levels on March 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: 360 km/s. Solar Wind speed from STEREO A: 620 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 large area on the visible solar disk has characteristics of coronal hole. This area (CH858) is an extension of the southern polar coronal hole and will probably affect the geomagnetic conditions on March 22-25. 5. Geophysical Activity Forecast The geomagnetic field is expected to be at quiet to unsettled levels on March 21, at quiet to minor storm levels on March 22 and at quiet to active levels on March 23 due to CH858 effects. Date Estimated Ap index Expected geom. storm 2018.03.21 08 - 2018.03.22 16 G1 2018.03.23 14 - *************************************************************************** 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 ***************************************************************************