Product: Weekly Highlights and Forecasts
:Issued: 2025 May 26 0140 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 19 - 25 May 2025
Solar activity ranged from low to high levels. Region 4098 (S04, L=021, class/area=Dai/170 on 25 May) produced the strongest event of the period, an impulsive X1.1 flare (R3-Strong) at 25/0152 UTC. An associated Tenflare (170 sfu) and subsequent, narrow CME was observed. The CME was oriented far to the west and no expected to contain an Earth-directed component. The region also produced an impulsive M8.9/2b (R2-Moderate) event at 25/1630 UTC. Region 4087 (N15, L=057, class/area=Dso/240 on 18 May) was the only other region to produce an event above R1 (Minor) with an M1.2/Sn flare at 21/0008 UTC.
No Earth-directed CMEs were observed in available coronagraphimagery.
No proton events were observed at geosynchronous orbit.
The greater than 2 MeV electron flux at geosynchronous orbit reached high levels on 18-19 May and 21-24 May in response to a high-speed stream from a large, polar-crown-connected coronal hole. 20 May and 25 May electron flux was at normal to moderate levels.
Geomagnetic field activity was at quiet to unsettled over 19-20 May. An isolated period of active conditions were observed on 21 May. Quiet conditions were observed over 22-25 May. The solar wind was under the influence of a positive polarity CH HSS for the week. Solar wind speeds reached of peak of ~630 km/s on 21 May andgradually waned over the following days.
Forecast of Solar and Geomagnetic Activity 26 May - 21 June 2025
Solar activity is likely to reach moderate levels
(R1-R2/Minor-Moderate), with a chance for R3 (Strong), over the next three days as Region 4098 (S04, L=021, class/area=Dai/170 on 25 May), the most productive region on the visible disk, makes its way to the west limb of the Sun. A chance for M-class X-ray activity (R1-R2) will persist throughout the outlook period due to multiple regions on the visible as well as multiple active regions scheduled to return from the farside of the Sun.
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 30 May - 05 Jun and 14-21 Jun following recurrent coronal hole influence. The remainder of the period is expected to be at normal to moderate levels.
Geomagnetic field activity is expected to be at mostly elevated due to anticipated influence from multiple, recurrent coronal holes. G1 (minor) geomagnetic storms are likely on 13-14 Jun; active conditions are likely over 28-29 May, 02 Jun, 05 Jun, 10-11 Jun, and
15-17 Jun; unsettled conditions are likely over 26-27 May, 30 May - 01 Jun, 03-04 Jun, 06-07 Jun, and 18-21 Jun. Quiet conditions are only expected on 08-09 Jun.
Product: 27-day Space Weather Outlook Table 27DO.txt
:Issued: 2025 May 26 0140 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 2025-05-26
#
# UTC Radio Flux Planetary Largest
# Date 10.7 cm A Index Kp Index
2025 May 26 135 8 3
2025 May 27 130 8 3
2025 May 28 125 12 4
2025 May 29 125 15 4
2025 May 30 130 10 3
2025 May 31 125 8 3
2025 Jun 01 120 10 3
2025 Jun 02 115 12 4
2025 Jun 03 110 8 3
2025 Jun 04 110 10 3
2025 Jun 05 115 12 4
2025 Jun 06 120 10 3
2025 Jun 07 125 10 3
2025 Jun 08 125 5 2
2025 Jun 09 120 5 2
2025 Jun 10 115 15 4
2025 Jun 11 120 12 4
2025 Jun 12 125 12 4
2025 Jun 13 120 30 5
2025 Jun 14 125 20 5
2025 Jun 15 125 12 4
2025 Jun 16 130 12 4
2025 Jun 17 130 12 4
2025 Jun 18 125 8 3
2025 Jun 19 120 8 3
2025 Jun 20 115 8 3
2025 Jun 21 115 8 3
(NOAA)
