:Product: Forecast Discussion
:Issued: 2026 Apr 04 1230 UTC
# Prepared by the U.S. Dept. of Commerce, NOAA, Space Weather Prediction Center
#
Solar Activity

.24 hr Summary...
Solar activity reached high levels. Region 4409 (N02W08, Eai/beta-gamma)
produced an M7.5 flare (R2-Moderate) at 04/0117 UTC, the largest event
of the period, in addition to an M1.3 flare (R1-Minor) at 03/1250 UTC
and an M1.7/Sf flare (R1) at 04/0758 UTC. The region exhibited penumbral
growth while consolidating spots near its leader. The remaining spotted
regions on the visible disk were either mostly stable or in gradual
decay.

Other activity included a filament eruption near S33E10 beginning at
around 04/0930 UTC, as seen in SUVI-195 imagery, but no coronagraph
imagery was available beyond ~04/0900 UTC. No Earth-directed CMEs were
observed in available coronagraph imagery.

.Forecast...
Solar activity is likely to reach moderate (R1-R2/Minor-Moderate)
levels, with a slight chance for X-class (R3-Strong) flares, over 04-06
Apr driven primarily by the flare potential of Region 4409.

Energetic Particle

.24 hr Summary...
The greater than 2 MeV electron flux reached high levels with a peak
flux of 4,470 pfu observed at 03/1715 UTC. The greater than 10 MeV
proton flux remained elevated throughout the period, reaching a peak
flux of 5.7 pfu at 03/1305 UTC, but remained below S1 (Minor) levels.

.Forecast...
The greater than 2 MeV electron flux is expected to reach high levels
on 04-06 Apr. There is a slight chance for the greater than 10 MeV
proton flux to exceed S1 (Minor) solar radiation storm levels over 04-06
Apr.

Solar Wind

.24 hr Summary...
Solar wind parameters indicated influence from a negative polarity CH
HSS until 03/1503 UTC, when a IP shock was observed from the arrival of
a CME that left the Sun on 01 Apr. The shock increased the total
magnetic field strength from 5 nT to a peak of 14 nT. Bz was mostly
oriented southward, with a peak negative value of -11 nT observed at
03/1518 UTC. Solar wind speeds increased from ~625 km/s to ~800 km/s,
and then entered a gradual decline with values near 600 km/s by the end
of the period.

.Forecast...
The solar wind environment is expected to remain enhanced through 06 Apr
due to waning CME effects followed by negative polarity CH HSS
influences.

Geospace

.24 hr Summary...
The geomagnetic field reached G3 (Strong) geomagnetic storm levels
following the arrival of a CME that left the Sun on 01 Apr.

.Forecast...
The geomagnetic field is expected to reach G1 (Minor) storm levels on 04
Apr, with periods of G2 (Moderate) storming likely, due to waning CME
effects and negative polarity CH HSS influences. Periods of active
conditions are expected on 05 Apr, with quiet to unsettled levels
expected on 06 Apr, as negative polarity CH HSS influences gradually
wane.