954
FXXX12 KWNP 050031
DAYDIS

:Product: Forecast Discussion
:Issued: 2025 Dec 05 0030 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
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Solar Activity

.24 hr Summary...
Solar activity reached high levels. Region 4300 (N07E28, Dao/beta-delta)
produced an impulsive M6.0/1F (R2-Moderate) flare at 04/0250 UTC.
Associated with the flare was a Type-II radio sweep (est. 345 km/s) and
CME signature in subsequent coronagraph imagery beginning at 04/0312 UTC
in SOHO/LASCO C2. CME analysis and model output suggested no
Earth-directed component. A Type-IV radio sweep may have been associated
with a CME originating from the SE quadrant, first observed in C2
imagery at 04/0648 UTC, in the vicinity of Region 4296 (S14E23,
Ekc/beta-gamma-delta). Modelling of the event suggested the periphery of
the CME may pass Earth late on 07 Dec.

Growth was observed in Region 4301 (S07W58, Dai/beta). Slight decay was
observed in Region 4294 (S15E04, Fkc/beta-gamma-delta) and Region 4296
(S14E23, Ekc/beta-gamma-delta). A new region of emerging flux was
observed in the SW quadrant. Only minor changes were observed in other
numbered active regions on the visible disk.

.Forecast...
M-class flares are expected (75%) through 07 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 was at
normal to moderate levels. 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 remain at moderate
levels on 05 Dec. High levels are likely on 06-07 Dec due to elevated
solar wind speeds associated with the ongoing CH HSS.

A slight chance (15%) exists for a greater than 10 MeV proton flux
enhancement above 10 pfu (S1-Minor) through 07 Dec due to the eruptive
potential of multiple active regions across the visible disk.

Solar Wind

.24 hr Summary...
Solar wind parameters reflected the transition from CIR to negative
polarity CH HSS influences. Total magnetic field strength decreased from
a peak of 20 nT at the beginning of the reporting period to 7-9 nT after
04/0430 UTC. Bz briefly reached as far south as -14 nT at 04/0226 UTC.
Solar wind speeds increased to a peak just above 700 km/s at 04/0450
UTC, before gradually waning in the hours the followed. Phi was
predominantly oriented in a negative solar sector.

.Forecast...
The solar wind environment is anticipated to remain disturbed by the
negative polarity CH/HSS influences over 05-07 Dec. An additional
enhancement is likely late on 07 Dec due to glancing effects from the 04
Dec CME.

Geospace

.24 hr Summary...
Geomagnetic activity reached G1 (Minor) geomagnetic storm levels early
in the period due to coronal hole influences.

.Forecast...
The geomagnetic field is likely to reach active levels, with a chance
for G1 (Minor) storm levels, over 05-06 Dec as influence from the
coronal hole wanes. G1 geomagnetic storm levels are likely on 07 Dec due
to the anticipated onset of influence from the periphery of a CME that
left the Sun on 04 Dec.