Product: Weekly Highlights and Forecasts
:Issued: 2025 Sep 29 0238 UTC
# Prepared by the US Dept. of Commerce, NOAA, Space Weather Prediction Center
# Product description and SWPC web contact www.swpc.noaa.gov/content/subscription-services
#
# Weekly Highlights and Forecasts
#
Highlights of Solar and Geomagnetic Activity 22 - 28 September 2025
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| Graphic design by Gayle Van Horn |
Solar activity reached R1 (Minor) levels on 23, 24, 26 and 27 Sep and R2 (Moderate) levels on 28 Sep. Region 4217 (S16, L=209, class/area Cko/250 on 22 Sep) produced an M1.1 flare at 23/1034 UTC with an associated Type II sweep with an estimated shock velocity of 835 km/s. On 24 Sep, Region 4224 (S14, L=205, class/area Dso/060 on 26 Sep) produced an M1.0 and an M1.6 flare at 24/0931 UTC and 24/1913 UTC, respectively. An M1.6 flare was observed from behind the E limb at 26/2001 UTC with an associated Type II sweep with an estimated shock velocity of 778 km/s.
Region 4226 (S11, L=133, class/area on 24 Sep) produced an M1.0/Sf flare and an M1.1/Sf flare at 27/0359 UTC and 27/0423 UTC, respectively. Later on 26 Sep, another activity produced an Earth-directed CMEs.
No proton events were observed at geosynchronous orbit.
The greater than 2 MeV electron flux at geosynchronous orbit was at high levels on 22 and 27 Sep with a maximum flux of 1,723 pfu observed at 27/1655 UTC. Normal to moderate levels were observed on 23-26 and 28 Sep.
Geomagnetic field activity was at quiet to unsettled levels, with an isolated active period midday on 23 Sep. Weak negative polarity CH HSS's dominated the period. Solar wind speeds reached a maximum speed of about 600 km/s midday on 23 Sep.
Forecast of Solar and Geomagnetic Activity 29 September - 25 October 2025
Solar activity is expected to be at low levels with a likely chance for isolated M-class flares throughout the period.
No proton events are expected at geosynchronous orbit.
The greater than 2 MeV electron flux at geosynchronous orbit is expected to be at high levels on 05-08 Oct, 13-16 Oct and 21-24 Oct. Normal to moderate levels are expected for the remainder of the outlook period.
Geomagnetic field activity is expected to be at unsettled to active periods on 29-30 Sep, 11-13 Oct, 19-22 Oct and 25 Oct, all due to negative polarity CH HSS influences. Unsettled to active periods are expected on 03-06 Oct due to positive polarity CH HSS influences. Mostly quiet levels are likely for the remaining days in the outlook period.
:Product: 27-day Space Weather Outlook Table 27DO.txt
:Issued: 2025 Sep 29 0238 UTC
# Prepared by the US Dept. of Commerce, NOAA, Space Weather Prediction Center
# Product description and SWPC web contact www.swpc.noaa.gov/content/subscription-services
#
# 27-day Space Weather Outlook Table
# Issued 2025-09-29
#
# UTC Radio Flux Planetary Largest
# Date 10.7 cm A Index Kp Index
2025 Sep 29 175 14 4
2025 Sep 30 180 8 3
2025 Oct 01 180 5 2
2025 Oct 02 175 5 2
2025 Oct 03 170 12 4
2025 Oct 04 170 8 3
2025 Oct 05 165 8 3
2025 Oct 06 165 8 3
2025 Oct 07 165 5 2
2025 Oct 08 155 5 2
2025 Oct 09 155 5 2
2025 Oct 10 155 5 2
2025 Oct 11 145 15 5
2025 Oct 12 145 12 4
2025 Oct 13 140 8 3
2025 Oct 14 140 5 2
2025 Oct 15 145 5 2
2025 Oct 16 150 5 2
2025 Oct 17 155 5 2
2025 Oct 18 155 5 2
2025 Oct 19 160 12 4
2025 Oct 20 160 15 5
2025 Oct 21 165 8 3
2025 Oct 22 160 8 3
2025 Oct 23 155 5 2
2025 Oct 24 155 5 2
2025 Oct 25 150 12 4
(NOAA)
