Subject: Weekly Highlights of Solar and Geomagnetic Activity, 14 - 20 April 2025

: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 contact on the Web
# https://www.swpc.noaa.gov/content/subscription-services
#
# Weekly Highlights and Forecasts
#
Highlights of Solar and Geomagnetic Activity
14 - 20 April 2025

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.


--- MBSE BBS v1.1.1 (Linux-x86_64)
* Origin: NOAA Space Weather Prediction Center (3:633/280.2@fidonet)