:Product: 1208RSGA.txt
:Issued: 2025 Dec 08 2200 UTC
# Prepared jointly by the U.S. Dept. of Commerce, NOAA,
# Space Weather Prediction Center and the U.S. Air Force.
#
Joint USAF/NOAA Solar Geophysical Activity Report and Forecast
SDF Number 342 Issued at 2200Z on 08 Dec 2025

IA.  Analysis of Solar Active Regions and Activity from 07/2100Z to
08/2100Z: Solar activity has been at high levels for the past 24 hours.
There are currently 8 numbered sunspot regions on the disk.
IB.  Solar Activity Forecast: Solar activity is likely to be moderate
with a slight chance for an X-class flare on days one, two, and three
(09 Dec, 10 Dec, 11 Dec).

IIA.  Geophysical Activity Summary 07/2100Z to 08/2100Z: The geomagnetic
field has been at quiet levels for the past 24 hours. Solar wind speed
reached a peak of 594 km/s at 08/1918Z. Total IMF reached 7 nT at
07/2210Z. The maximum southward component of Bz reached -4 nT at
08/2055Z.  Electrons greater than 2 MeV at geosynchronous orbit reached
a peak level of 1039 pfu.
IIB.  Geophysical Activity Forecast: The geomagnetic field is expected
to be at active to severe storm levels on day one (09 Dec), quiet to
minor storm levels on day two (10 Dec) and quiet to unsettled levels on
day three (11 Dec). Protons have a slight chance of crossing threshold
on days one, two, and three (09 Dec, 10 Dec, 11 Dec).

III.  Event probabilities 09 Dec-11 Dec
Class M    65/65/65
Class X    15/15/15
Proton     15/15/15
PCAF       green

IV.  Penticton 10.7 cm Flux
Observed           08 Dec 186
Predicted   09 Dec-11 Dec 190/185/175
90 Day Mean        08 Dec 149

V.  Geomagnetic A Indices
Observed Afr/Ap 07 Dec  005/009
Estimated Afr/Ap 08 Dec  013/018
Predicted Afr/Ap 09 Dec-11 Dec  044/066-022/033-007/010

VI.  Geomagnetic Activity Probabilities 09 Dec-11 Dec
A.  Middle Latitudes
Active                20/35/20
Minor Storm           30/35/05
Major-severe storm    50/20/01
B.  High Latitudes
Active                05/05/15
Minor Storm           15/20/25
Major-severe storm    85/75/25
