:Product: Forecast Discussion
:Issued: 2026 Jun 26 0030 UTC
# Prepared by the U.S. Dept. of Commerce, NOAA, Space Weather Prediction Center
#
Solar Activity

.24 hr Summary...
Solar activity was at low levels, with frequent C-level activity in the
SE quadrant of the solar disk. The largest flare of the period was a
C6.6/1N at 25/1503 UTC from Region 4478 (S06E63, Fhc/beta-gamma-delta),
which has rotated far enough onto the disk to mitigate foreshortening
effects, allowing a delta configuration to be observed. While the
majority of the flaring activity this period came from 4478, Region 4475
(S09E07, Eki/beta-gamma) also produced several C-flares as its trailing
and intermediary spots continued to grow and consolidate. Regions 4477
(S13E41, Cri/beta) and 4479 (N16E45, Cro/beta) showed new emergence late
in the period. All other regions on the disk are either largely stable
or in slight decay.

No Earth-directed CMEs were observed in available coronagraph imagery.

.Forecast...
Solar activity is expected to continue at predominately low levels on
26-28 Jun, with a high chance for M-flares (R1-R2/Minor-Moderate) and a
slight chance for X-flares (R3/Strong or greater), primarily due to the
potential of Region 4478.

Energetic Particle

.24 hr Summary...
The greater than 2 MeV electron flux was at normal to moderate levels.
The greater than 10 MeV proton flux was at background levels.

.Forecast...
The greater than 2 MeV electron flux is expected to continue at normal
to moderate levels over 26-28 Jun. The greater than 10 MeV proton flux
is expected to persist at background levels through 28 Jun.

Solar Wind

.24 hr Summary...
Solar wind parameters were elevated this period from negative
polarity coronal hole high speed stream influences. Total magnetic field
strength (Bt) began the reporting period at ~10 nT and slowly decreased
to less than 5 nT by the end of the period, with a variable Bz component
that had several southward deflections between -5 and -10 nT. The solar
wind speed began the period at ~655 km/s and gradually increased to an
average of 700 km/s.  Phi was largely in a negative (towards the Sun)
orientation.

.Forecast...
Solar wind conditions are expected remain elevated/disturbed through 27
Jun due to the continued influence of the negative polarity CH HSS.
Early on 28 Jun, a CME that left the Sun on 22 Jun may arrive at Earth
orbit and disturb the near-Earth environment even further.

Geospace

.24 hr Summary...
The geomagnetic field was largely at unsettled to active conditions,
with one isolated period of G1 (Minor) storming conditions.

.Forecast...
Periods of active conditions are likely on 26-28 Jun due to the negative
polarity CH HSS influences and a potential CME arrival on 28 Jun.