124
FXXX12 KWNP 181231
DAYDIS

:Product: Forecast Discussion
:Issued: 2024 Sep 18 1230 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
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#             Forecast Discussion
#
Solar Activity

.24 hr Summary...
Solar activity was at low levels. The largest flare was a C4.1 at
18/0344 UTC from Region 3828 (S13E54, Hsx/alpha). Slight growth occurred
in Region 3825 (S15W01, Esc/beta-gamma). Region 3824 (S04W61,
Eao/beta-gamma) appeared to have decay in its intermediate and trailing
spots. New Regions 3829 (N11W59, Cro/beta) and 3830 (N15W60, Axx/alpha)
were numbered. No Earth-directed CMEs were observed.

.Forecast...
Solar activity is likely to reach moderate (R1-R2, Minor-Moderate), with
a slight chance for X-class flares (R3-Strong), on 18-19 Sep.
Probabilities are decreasing to a chance for M-class flares on 20 Sep as
Regions 3824 and 3826 rotate around the W limb.

Energetic Particle

.24 hr Summary...
The greater than 2 MeV electron flux was at moderate levels . The
greater than 10 MeV proton flux levels decreased to 1 pfu by the end of
the period.

.Forecast...
The greater than 2 MeV electron flux is expected to be at normal to
moderate levels on 18-20 Sep due to CME influence. The greater than 10
MeV proton flux is expected to slowly diminish over 18-20 Sep.

Solar Wind

.24 hr Summary...
Solar wind parameters were indicative of waning CME influences. Total
field gradually decreased from 13 - 7 nT. The Bz component was +/- 6 nT
for the vast majority of the period. Solar wind speeds decreased from
~500-450 km/s. Phi was mostly positive.

.Forecast...
CME influence is expected to slowly wane through 18 Sep. A return to
near nominal levels is expected on 19-20 Sep.

Geospace

.24 hr Summary...
The geomagnetic field reached G2 (Moderate) storm levels early in the
period due to the arrival of the 14 Sep CME.

.Forecast...
Quiet to active levels are likely on 18 Sep as CME effects wane. Quiet
to unsettled levels are expected on 19 Sep followed by mostly quiet
conditions on 20 Sep.