:Product: 1210RSGA.txt
:Issued: 2025 Dec 10 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 344 Issued at 2200Z on 10 Dec 2025

IA.  Analysis of Solar Active Regions and Activity from 09/2100Z to
10/2100Z: Solar activity has been at high levels for the past 24 hours.
There are currently 7 numbered sunspot regions on the disk.
IB.  Solar Activity Forecast: Solar activity is expected to be moderate
with a slight chance for an X-class flare on day one (11 Dec) and likely
to be moderate with a slight chance for an X-class flare on day two (12
Dec) and likely to be moderate on day three (13 Dec).

IIA.  Geophysical Activity Summary 09/2100Z to 10/2100Z: The geomagnetic
field has been at quiet to unsettled levels for the past 24 hours. Solar
wind speed reached a peak of 474 km/s at 10/2053Z. Total IMF reached 17
nT at 10/2018Z. The maximum southward component of Bz reached -15 nT at
10/2046Z.  Electrons greater than 2 MeV at geosynchronous orbit reached
a peak level of 2183 pfu.
IIB.  Geophysical Activity Forecast: The geomagnetic field is expected
to be at quiet to unsettled levels on days one and two (11 Dec, 12 Dec)
and quiet to active levels on day three (13 Dec). Protons greater than
10 Mev have a slight chance of crossing threshold on day one (11 Dec)
and have a slight chance of crossing threshold on day two (12 Dec).

III.  Event probabilities 11 Dec-13 Dec
Class M    75/65/65
Class X    15/10/05
Proton     15/10/05
PCAF       green

IV.  Penticton 10.7 cm Flux
Observed           10 Dec 168
Predicted   11 Dec-13 Dec 175/170/165
90 Day Mean        10 Dec 150

V.  Geomagnetic A Indices
Observed Afr/Ap 09 Dec  004/005
Estimated Afr/Ap 10 Dec  011/014
Predicted Afr/Ap 11 Dec-13 Dec  007/009-011/014-009/012

VI.  Geomagnetic Activity Probabilities 11 Dec-13 Dec
A.  Middle Latitudes
Active                20/20/40
Minor Storm           05/05/20
Major-severe storm    01/01/05
B.  High Latitudes
Active                15/15/15
Minor Storm           25/25/30
Major-severe storm    25/25/50
