Product: Daily Forecast of Geomagnetic Activity
Issued: 2017 November 21 08:10UTC
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 20.11.2017 at 20:00 UTC was 74 sfu.
The background X-Ray flux is at the class A5 level.
The geomagnetic field was at very quiet to active levels on November 20.
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: 580 km/s.
Solar Wind speed from STEREO A: 450 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 (CH837) was in Earth facing position on November 16-17. A high speed stream of solar wind finally reached Earth on the last hours of November 20.

5. Geophysical Activity Forecast
The geomagnetic field is expected to be at unsettled to minor storm levels on November 21, at quiet to active levels on November 22 and at quiet to unsettled levels on November 23.

Date Estimated Ap index Expected geom. storm
2017.11.21 23 G1
2017.11.22 15 -
2017.11.23 10 -

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