236
FXXX12 KWNP 031231
DAYDIS

:Product: Forecast Discussion
:Issued: 2025 Dec 03 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
#
#             Forecast Discussion
#
Solar Activity

.24 hr Summary...
Solar activity was at low levels with only C-class flares. Region 4294
(S15E16, Fkc/beta-gamma-delta) remains the largest region on the disk
but is appearing to be simplifying magnetically. Region 4296 (S14E36,
Ekc/beta-delta), on the other hand, gained a delta region in its
intermediary region, though with no corresponding increase in flare
activity as of yet. New flux emerged along the eastern side of Region
4298 (S16E03, Cao/beta), resulting in several C-flares throughout the
reporting period. Region 4299 (N23E41, Dac/beta-delta), also developed a
delta region in its primary spot but no appreciable shear was observed.
Region 4301 (S11W41, Axx/alpha) developed, was numbered, but was
otherwise unremarkable.

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

.Forecast...
Isolated to occasional M-class flares are expected (75%) through 05 Dec,
with a chance for X-class flares (30%), given past flare history and the
potential of current active regions on the disk.

Energetic Particle

.24 hr Summary...
The greater than 2 MeV electron flux in geosynchronous orbit continued
at high levels with a peak flux of 8,540 particle flux units reached
near 02/1715 UTC. The greater than 10 MeV proton flux in geosynchronous
orbit remained at background levels.

.Forecast...
The greater than 2 MeV electron flux is expected to continue to at high
levels, although gradually decreasing, through 03 Dec. A return to
moderate levels 04-05 Dec is likely with the initial onset of fast solar
wind associated with a coronal hole high speed stream and/or shock
arrival from the 01 Dec CME.

An enhancement to the 10 MeV proton flux in geosynchronous orbit due to
the aforementioned X1.9 event from 01 Dec cannot be ruled out as
sometimes events from the eastern limb take tens of hours to days to
reach Earth. This combined with the flare potential currently exhibited
by Earth-facing active regions will keep 10 MeV protons at a slight risk
(15%) of reaching the 10 particle flux unit threshold through 05 Dec.

Solar Wind

.24 hr Summary...
Solar wind parameters became enhanced late this reporting period. Total
field increased to 11-12 nT and the Bz component (North/South) deflected
southward, reaching -9 nT. Solar wind speeds however continued a
decreasing trend, ending the period under 400 km/s. Phi remained
positive, but the current enhancement may be indicating an eminent solar
sector boundary crossing to a negative orientation.

.Forecast...
Further disturbances in the solar wind environment are anticipated to
arrive at Earth by late on 03 Dec. First, phi is expected to
enter the negative solar sector followed by the arrival of enhanced
magnetic field ahead of fast solar wind associated with a recurrent,
equatorial, negative polarity coronal hole high speed stream. This
disturbance may be further enhanced by the glancing blow from the shock
produced by a eastern limb coronal mass ejection that was associated
with the aforementioned X1.9 flare on 01 Dec. While the disturbances
from shock arrivals are typically brief, the enhancements of this
combined phenomena is anticipated to continue through 04 Dec, with
lingering effects possible on 05 Dec.

Geospace

.24 hr Summary...
Geomagnetic field activity was quiet with a few isolated unsettled
periods throughout the reporting period.

.Forecast...
The geomagnetic field is expected to remain at unsettled to active
levels on 03 Dec. Unsettled to active levels are likely to give way
to G1-G2 (Minor-Moderate) storming periods by late 03 Dec due to the
phenomena described in the solar wind section. G1-G2 (Minor-Moderate)
storming is then likely to continue into 04 Dec. It should also be noted
that a chance (25%) for isolated periods of G3 (Strong) geomagnetic
storming will exist on 03 and 04 Dec, especially if the corotating
interaction region ahead of the high speed stream arrives with embedded
shock from the 01 Dec CME. Otherwise, G1-G2 (Minor-Moderate) conditions
will most likely diminish to mostly active levels as 04 Dec draws to a
close. 05 Dec will likely remain at unsettled to active levels as the
system recovers.

-WC