*********************************************************************** Product: Daily Forecast of Geomagnetic Activity Issued: 2019 September 26 05:29UTC 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 25.09.2019 at 20:00 UTC was 68 sfu. The background X-Ray flux is at the class ‘6 level. The geomagnetic field was at very quiet levels on September 25. 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: 395 km/s. Solar Wind speed from STEREO A: 390 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 new equatorial coronal hole (CH938) will be in Earth facing position on September 24-25. A high speed stream of solar wind is expected to reach Earth on the second half of September 27. 5. Geophysical Activity Forecast The geomagnetic field is expected to be at quiet to unsettled levels on September 26 and at quiet to active levels, with a chance for minor storm intervals, on September 27 and at unsettled to moderate storm levels on September 28 due to CH938 effects. Date Estimated Ap index Expected geom. storm 2019.09.26 05 - 2019.09.27 16 G1 2019.09.28 36 G1 - G2 *************************************************************************** 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 ***************************************************************************