Product: Weekly Highlights and Forecasts
:Issued: 2025 Apr 21 0125 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 14 - 20 April 2025
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Solar activity reached moderate levels due to M-class flare activity on 14-15, 18 and 20 Apr. The largest event of the period was an M4.4 flare at 18/2350 UTC from an unseen source beyond the SE limb. No Earth-directed CMEs resulted from this week's solar activity.
No proton events were observed at geosynchronous orbit.
The greater than 2 MeV electron flux at geosynchronous orbit reached high levels on 14 Apr, with normal to moderate levels observed over 15-20 Apr.
Geomagnetic field activity began the period at quiet to active levels in response to negative polarity CH HSS influences on 14 Apr. Periods of G1-G2 (Minor-Moderate) storming was observed on 15 Apr, with periods of G1-G4 (Minor-Severe) storming observed on 16 Apr, due to the passage of a CME that left the Sun on 13 Apr. Remnant CME influences and bouts of southward IMF persisted on 17-18 Apr with quiet to active levels observed. Quiet to active levels were observed on 19 Apr, and quiet to G1 (Minor) levels were observed on 20 Apr, in response to prolonged periods of southward Bz.
Forecast of Solar and Geomagnetic Activity 21 April - 17 May 2025
Solar activity is expected to be predominately low with a varying chance for M-class (R1-R2/Minor-Moderate) flares throughout the forecast period.
No proton events are expected at geosynchronous orbit, barring significant flare activity.
The greater than 2 MeV electron flux at geosynchronous orbit is likely to reach high levels on 21-28 Apr, and 03-12 May. Normal to moderate levels are expected to prevail throughout the remainder of the period.
Geomagnetic field activity is likely to reach G2 (Moderate) levels on 22-23 Apr, and G1 (Minor) levels on 24-25 Apr, due to the anticipated influence of a positive polarity CH HSS. Periods of G1 storms are likely on 01 May, and periods of G2 storms are likely on 02 May, due negative polarity CH HSS influences. The geomagnetic field is likely to reach G1 storm levels again over 05-11 May due to the influences of another negative polarity CH HSS.
Product: 27-day Space Weather Outlook Table 27DO.txt
:Issued: 2025 Apr 21 0125 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 2025-04-21
#
# UTC Radio Flux Planetary Largest
# Date 10.7 cm A Index Kp Index
2025 Apr 21 160 12 4
2025 Apr 22 165 35 6
2025 Apr 23 165 35 6
2025 Apr 24 165 25 5
2025 Apr 25 165 18 5
2025 Apr 26 165 8 3
2025 Apr 27 165 8 3
2025 Apr 28 170 6 2
2025 Apr 29 170 6 2
2025 Apr 30 170 6 2
2025 May 01 170 25 5
2025 May 02 175 35 6
2025 May 03 170 20 4
2025 May 04 165 12 4
2025 May 05 165 25 5
2025 May 06 165 20 5
2025 May 07 160 18 5
2025 May 08 165 18 5
2025 May 09 165 18 5
2025 May 10 165 15 5
2025 May 11 160 18 5
2025 May 12 155 5 2
2025 May 13 155 5 2
2025 May 14 155 5 2
2025 May 15 155 5 2
2025 May 16 155 12 4
2025 May 17 155 12 4
(NOAA)
