*********************************************************************** Product: Daily Forecast of Geomagnetic Activity Issued: 2025 October 13 08:12UTC Prepared by the Athens Space Weather Forecasting Center ***********************************************************************
I. Solar activity --Current Status Solar Flux (10.7cm) measured on 12.10.2025 at 23:00 UTC was 143 sfu. The background X-Ray flux is at the class C7.1 level. No obviously Earth directed CMEs were observed in available LASCO imagery on October 08-10. An equatorial coronal hole (CH1322) rotaded across the central meridian on October 07-10.
II. Solar Energetic Particle Events Protons and electrons fluxes are quiet.
III. Interplanetary and Geomagnetic conditions The solar wind speed measured by ACE satellite reached the max value 781 Km/s on October 12 at 10:50 UT during the last 24 hours. The solar wind speed from STEREO A was detected 400 Km/s during the last 24 hours. The vertical component of IMF Bz reached the max value -7 nT on October 12 at 17:35 UT during the last 24 hours. The geomagnetic field was at active to minor storm (G1) levels during the last 24 hours. The Kp index now is at minor storm (G1) levels with Kp=4.
IV. 3-day Geomagnetic Activity Forecast The geomagnetic field is expected to be at quiet to minor storm (G1) levels on October 13 due to the effect of recurrent coronal hole high speed stream and at quiet to unsettled levels on October 14-15.
Date
Ap index forecast
Geomagnetic Activity level
13.10.2025
20
Quiet to Minor storm (G1)
14.10.2025
12
Quiet to Unsettled
15.10.2025
08
Quiet to Unsettled
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