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Product: Daily Forecast of Geomagnetic Activity
Issued: 2025 September 28 07:27UTC
Prepared by the Athens Space Weather Forecasting Center
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I. Solar activity
--Current Status
Solar Flux (10.7cm) measured on 27.09.2025 at 23:00 UTC was 164 sfu.
The background X-Ray flux is at the class C2.3 level.
Three M-class flares were produced on September 27.
No obviously Earth directed CMEs were observed in available LASCO imagery on September 24-26.
A small coronal hole (CH1319) at northern hemisphere was Earth facing on September 25. 
A trans equatorial coronal hole (CH1320) will probably rotate across the central meridian on September 29.
A coronal hole (CH1321) at southern hemisphere will likely become Earth facing on September 29.

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 428 Km/s on September 28 at 06:30 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 September 27 at 19:00 UT during the last 24 hours.
The geomagnetic field was at quiet to unsettled levels during the last 24 hours.
The Kp index now is at unsettled levels with Kp=3.

IV. 3-day Geomagnetic Activity Forecast
The geomagnetic field is expected to be at quiet to unsettled levels on September 28-30.

Date	Ap index forecast	Geomagnetic Activity level	
28.09.2025	12	Quiet to Unsettled	
29.09.2025	12	Quiet to Unsettled	
30.09.2025	08	Quiet to Unsettled	

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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
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