004
FXXX12 KWNP 211206
DAYDIS

:Product: Forecast Discussion
:Issued: 2026 Aug 21 1205 UTC
# Prepared by the US Dept. of Commerce, NOAA, Space Weather Prediction Center
# Product description and SWPC contact on the Web
# http://www.swpc.noaa.gov/wwire.html
#
#             Forecast Discussion
#
Solar Activity

.24 hr Summary...
Solar activity reached moderate levels with two M-class (R1-Minor)
flares: an M2.9/1f solar flare at 20/1611 UTC from Region 4513 (N04E62,
Eac/beta-gamma-delta) and a long-duration M1.6 peaked at 21/1018 UTC
from the West limb, likely from Region 4507 (N04, L=198). The M1.6 flare
was accompanied by a Tenflare (140 sfu) peaked at 21/0934 UTC. Region
4513 continued to grow and was the main source of the C-class flares
observed in the past 24h. Region 4507 rotated off the West limb but also
contributed to the C-class activity of the day. A new Region 4515
(S08E70, Hrx/alpha) rotated into the visible disk and was numbered
during the period.

Three main CMEs were observed during the period: the first, around
20/1200 UTC (NE limb), was associated with an M8.1/Sf occurred at
20/1142 UTC from Region 4513. That CME trajectory was analyzed and no
Earth-directed component was identified. The second CME was far-sided,
first observed around 20/1930 UTC (SW limb), and likely associated with
a Type II event (est. 927 km/s) observed beginning at 20/1848 UTC. The
third CME, also far-sided, was associated with the M1.6 flare and first
observed by SOHO/LASCO-C2 coronagraph around 21/0924 UTC.

No Earth directed CME was observed in the coronagraph imagery available
during the period.

.Forecast...
Solar activity is expected to be at low levels, with a high chance for
isolated M-class flares (R1-R2/Minor-Moderate) and a slight chance for
X-class events (R3/Strong) on 21-23 Aug, mostly due to the flare
potential of Region 4315 and remaining influences of Region 4507 beyond
the west limb.

Energetic Particle

.24 hr Summary...
The greater than 2 MeV electron flux at geosynchronous orbit reached the
threshold of 1,000 pfu at 21/1105 UTC and remained around it until the
end of the period. The greater than 10 MeV proton flux at geosynchronous
orbit remained at background levels.

.Forecast...
The greater than 2 MeV electron flux is likely to remain at high levels
on 21-23 Aug due to CH HSS influences. The greater than 10 MeV proton
flux is expected to continue at background levels through 23 Aug.

Solar Wind

.24 hr Summary...
Solar wind parameters reflected the waning influences of a negative
polarity coronal hole HSS. Total magnetic field strength remained around
5 nT with Bz oscillating between +/- 5 nT during the period. Solar wind
speeds gradually decreased from 550 km/s to 500 km/s during the day. Phi
angle was predominately negative during the reporting period.

.Forecast...
Solar wind parameters near Earth are likely to continue reflecting
waning influence of a negative polarity coronal hole high speed stream
on 21-22 Aug, returning to undisturbed levels on 23 Aug.

Geospace

.24 hr Summary...
The geomagnetic field activity was quiet to unsettled during the period.

.Forecast...
The geomagnetic field is likely to reach active levels on 21-22 Aug as
the ongoing CH HSS influences near Earth wane. Unsettled levels are
likely on 23 Aug.