*********************************************************************** Product: Daily Forecast of Geomagnetic Activity Issued: 2019 September 28 06:49UTC 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 27.09.2019 at 20:00 UTC was 66 sfu. The background X-Ray flux is at the class A8 level. The geomagnetic field was at very quiet to minor storm levels on September 27. No obviously Earth directed CMEs were observed in available LASCO imagery. The Kp index now is at minor storm levels with Kp=5. 2. Solar Wind Geomagnetic Activity Solar Wind speed from ACE: 620 km/s. Solar Wind speed from STEREO A: 340 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 An equatorial coronal hole (CH938) was in Earth facing position on September 24-25. A high speed stream of solar wind finally reached Earth on the first half of September 27 just a few hours earlier than it was predicted. 5. Geophysical Activity Forecast The geomagnetic field is expected to be at unsettled to moderate storm levels on September 28, at quiet to minor storm levels on September 29 and at quiet to active levels on September 30 due to CH938 effects. Date Estimated Ap index Expected geom. storm 2019.09.28 36 G1 - G2 2019.09.29 20 G1 2019.09.30 12 - *************************************************************************** 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 ***************************************************************************