917
FXXX12 KWNP 180031
DAYDIS

:Product: Forecast Discussion
:Issued: 2025 Aug 18 0030 UTC
# Prepared by the US Dept. of Commerce, NOAA, Space Weather Prediction Center
# Product description and SWPC contact on the Web
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#             Forecast Discussion
#
Solar Activity

.24 hr Summary...
Solar activity was at low levels. The strongest event of the period was
a C3.7 at 17/0459 UTC from a region just around the W limb. Only minor
changes were observed among the numbered active regions on the visible
disk.

Other activity included a subtle eruption near in the vicinity of S12W15
around between 17/0900-1000 UTC. A subsequent CME signature was
identified in SOHO LASCO C2 imagery beginning at 17/1024 UTC. Analysis
and modeling of the event is ongoing.

.Forecast...
Solar activity is expected to continue at low levels, with a slight
chance for R1-R2 (Minor-Moderate) radio blackouts, on 18-20 August.

Energetic Particle

.24 hr Summary...
The greater than 2 MeV electron flux reached high. The greater than 10
MeV proton flux remained at background level.

.Forecast...
The greater than 2 MeV electron flux is expected to be at moderate to
high levels through 20 Aug. The greater than 10 MeV proton flux is
expected to remain at background levels through 20 Aug.

Solar Wind

.24 hr Summary...
Solar wind parameters reflected nominal conditions. Total magnetic field
strength was near 5 nT through most of the day. No significant periods
of southward Bz were observed. Solar wind speeds remained slow with
values remaining between ~300-350 km/s. Phi angle was predominately
oriented in the positive solar sector.

.Forecast...
Enhanced solar wind parameters are likely on late on 18 Aug and through
20 Aug due to the arrival of a CIR ahead of a recurrent, negative
polarity CH HSS.

Geospace

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

.Forecast...
The geomagnetic field is likely to continue at quiet levels over most of
18 Aug. Late on 18 Aug, conditions are likely to increase to active
levels followed by G1 (Minor) geomagnetic storm levels on 19 Aug. Active
conditions are likely to over 20 Aug. The increases in activity are due
to the anticipated onset of influence from a recurrent, negative
polarity CH HSS.