:Product: Forecast Discussion
:Issued: 2026 Jun 17 0030 UTC
# Prepared by the U.S. Dept. of Commerce, NOAA, Space Weather Prediction Center
#
Solar Activity

.24 hr Summary...
Solar activity was at very low to low levels. C1 flares occurred at
16/0048 UTC and 16/1532 UTC from Regions 4470 (N07E68, Dro/beta) and
4464 (S14W86, Hsx/alpha), respectively. Region 4465 (N07W35, Dai/beta)
appeared to be in decay. The rest of the spot groups were either stable
or in decay. No Earth-directed CMEs were observed.

.Forecast...
Solar activity is expected to remain at low levels over 17-19 Jun, with
a slight chance for M-class (R1-R2/Minor-Moderate) flares.

Energetic Particle

.24 hr Summary...
The greater than 2 MeV electron flux reached high levels, with peak
value of 2,043 pfu observed at 16/1525 UTC. The greater than 10 MeV
proton flux remained at background levels.

.Forecast...
The greater than 2 MeV electron flux is likely to reach high levels on
17 Jun and decrease to moderate levels on 18-19 Jun. The greater than 10
MeV proton flux is expected to continue at background levels through 19
Jun.

Solar Wind

.24 hr Summary...
Solar wind parameters were near nominal levels with solar wind speed
ranging from 363-450 km/s. Total field ranged from 5-8 nT while the Bz
component was between +/-7 nT. Phi orientation switched into a positive
sector at 16/1657 UTC.

.Forecast...
Solar wind parameters are expected to be influenced by a series of
positive polarity CH HSS over the forecast period beginning mid to late
on 17 Jun. Solar wind speeds in the 450-550 km/s range are likely.

Geospace

.24 hr Summary...
The geomagnetic field was quiet.

.Forecast...
Unsettled to active levels are expected on 17 and 19 Jun with quiet to
unsettled levels on 18 Jun due to CH HSS effects.