Product: Daily Forecast of Geomagnetic Activity
Issued: 2018 December 18 05:57UTC
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 17.12.2018 at 20:00 UTC was 70 sfu.
The background X-Ray flux is at the class A3 level.
The geomagnetic field was at almost quiet levels on December 17.
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: 410 km/s.
Solar Wind speed from STEREO A: 350 km/s.
Solar Wind speed from STEREO B: --- km/s.
The southward component Bz is: 4 nT north.

3. Solar Energetic Particle Events
Protons and electrons are quiet.

4. Coronal Holes
A new coronal hole (CH900) which is an extension of the southern polar coronal hole was in Earth facing position on December 12-13. A slow solar wind stream associated with CH900 arived on Earth on the first hours of December 17 producing minor geomagnetic impact up to now.

5. Geophysical Activity Forecast
The geomagnetic field is expected to be at quiet to unsettled levels on December 18-19 due to CH900 effects and at quiet levels on December 20.

Date Estimated Ap index Expected geom. storm
2018.12.18 06 -
2018.12.19 05 -
2018.12.20 03 -

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