964
FXXX12 KWNP 041231
DAYDIS

:Product: Forecast Discussion
:Issued: 2025 Oct 04 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 moderate levels. Departed Region 4238 (S14, L=117)
produced the strongest event of the period, an M1.2 (R1-Minor) flare at
03/1436 UTC. Associated with the flare was a Type II radio sweep with an
estimated shock velocity of 416 km/s. Region 4242 (S11E20, Dro/beta)
produced numerous C-class flares as this region showed some overall
growth. The remaining regions were quiet and stable.

Finally, a filament eruption was observed near the ESE limb beginning at
~03/1830 UTC. WSA-Enlil model output suggested an arrival at Earth late
on 08 Oct.

.Forecast...
Solar flare activity is likely to remain at moderate levels
(R1-R2/Minor-Moderate), with a slight chance for strong (R3-Strong),
over 04-06 Oct.

Energetic Particle

.24 hr Summary...
The greater than 2 MeV electron flux measured by the GOES-19 satellite
reached high levels, with a peak flux of 7,331 pfu observed at 03/2025
UTC, due to a persistent +CH HSS effects. The greater than 10 MeV proton
fluxes, as measured by the GOES-18 satellite, remained below the S1
(Minor) threshold over the past 24 hrs.

.Forecast...
The greater than 2 MeV electron flux is expected to remain at high
levels as the CH HSS continues to be geoeffective over 04-06 Oct. The
greater than 10 MeV proton flux is expected to continue at or near
background level over the next few days, with a low (5%) chance for a
proton event, due to the presence of magnetically complex active
regions on the visible disk.

Solar Wind

.24 hr Summary...
The solar wind near Earth continued to be dominated by CH HSS
conditions, with Phi angle values representative of the positive sector
Wind speeds generally varied between 550-750 km/s during the period. The
total Interplanetary Magnetic Field (Bt) remained around 5 nT, with
north/south (Bz) component between -/+ 5 nT.

.Forecast...
Solar wind parameters are expected to continue at elevated, but waning
levels over 04-06 Oct due to persistent CH HSS influence.

Geospace

.24 hr Summary...
The geomagnetic activity reached active levels due to ongoing CH HSS
influence.

.Forecast...
The geomagnetic field is expected to reach active levels, with a chance
for G1 (Minor), over 04-06 Oct under continued CH HSS influence.