Product: Weekly Highlights and Forecasts
:Issued: 2025 Oct 27 0243 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 20 - 26 October 2025
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Solar activity was at moderate levels on 20 Oct with a single M-class flare observed. Region 4248 (N07, L=262, class/area=Eki/380 on 17 Oct) produced an M1.1 flare, the largest of the period, at 20/0527 UTC. Region 4262 (S12, L=132, class/area=Cai/150 on 22 Oct) produced a pair of long duration C-class flares. The first was a C4.7 that peaked at 22/0152 UTC, with the second being a C2.7 flare at 22/0909 UTC. Additionally, there were two far sided CMEs, likely originating from old Region 4246 (N24, L=290, class/area=Ekc/840 on 16 Oct). These events were observed in LASCO coronagraph imagery on 21/2024 UTC. Additionally, Type II (est. 2474 km/s) and Type IV radio sweeps were observed at 21/2011 UTC, likely associated with the far-sided events as well. There was also a weak CME observed in LASCO imagery on 23/1545 UTC, likely associated with a C2.1 flare at 23/1506 UTC from Region 4256 (S15, L=155, class/area=140/Dao on 18
Oct. This CME is expected to arrive at Earth on 27 Oct. Activity was at low levels from 21-26 Oct.
No proton events were observed at geosynchronous orbit. However, the 10 MeV proton flux levels were slightly elevated on 22-23 Oct following the far-sided CME eruptions. Conditions were at background levels on 20-21 Oct and 24-26 Oct. The greater than 2 MeV electron flux at geosynchronous orbit was at
normal to moderate levels from 20-26 Oct.
Geomagnetic field activity was at mostly quiet to unsettled levels from 20-26 Oct, with the exception of an isolated active period on 25 Oct, likely associated with residual CH HSS influence.
Forecast of Solar and Geomagnetic Activity 27 October - 22 November 2025
Solar activity is expected to be at moderate levels on 31 Oct - 15 Nov due to the return of Region 4246. Low levels are expected to prevail on 20 Oct - 30 Oct and 14 Nov - 22 Nov as multiple regions depart the visible disk. No proton events are expected at geosynchronous orbit from 27 Oct -
22 Nov. However, depending on the complexity of returning Region 4246, an isolated proton event is possible.
The greater than 2 MeV electron flux at geosynchronous orbit is expected to be at high levels from 31 Oct - 15 Nov due to responses from recurrent CH HSS influences. Moderate levels are expected on 27 - 30 Oct and 16 Nov - 22 Nov.
Geomagnetic field activity is expected to be at quiet to unsettled levels on 01 Nov - 06 Nov, 10 Nov - 14 Nov, and 16 Nov - 22 Nov. Active conditions are expected on 27 Oct and 31 Oct, 07 Nov - 09 Nov, and 15 Nov, with G1/G2 conditions likely on 28 Oct - 30 Oct due to recurrent positive polarity CH HSS influence, mixed with possible weak influence from the CME that left the Sun on 23 October
Product: 27-day Space Weather Outlook Table 27DO.txt
:Issued: 2025 Oct 27 0243 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 2025-10-27
#
# UTC Radio Flux Planetary Largest
# Date 10.7 cm A Index Kp Index
2025 Oct 27 120 5 2
2025 Oct 28 120 18 4
2025 Oct 29 120 18 4
2025 Oct 30 125 15 3
2025 Oct 31 130 12 3
2025 Nov 01 130 8 3
2025 Nov 02 130 5 2
2025 Nov 03 135 5 2
2025 Nov 04 140 5 2
2025 Nov 05 140 5 2
2025 Nov 06 140 8 3
2025 Nov 07 140 12 4
2025 Nov 08 145 20 5
2025 Nov 09 150 18 5
2025 Nov 10 155 8 3
2025 Nov 11 160 8 3
2025 Nov 12 165 5 2
2025 Nov 13 170 5 2
2025 Nov 14 175 5 2
2025 Nov 15 175 12 4
2025 Nov 16 165 8 3
2025 Nov 17 150 5 2
2025 Nov 18 150 5 2
2025 Nov 19 150 5 2
2025 Nov 20 150 8 3
2025 Nov 21 140 8 3
2025 Nov 22 140 5 2
(NOAA)
