:Product: 1227RSGA.txt
:Issued: 2025 Dec 27 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 361 Issued at 2200Z on 27 Dec 2025

IA.  Analysis of Solar Active Regions and Activity from 26/2100Z to
27/2100Z: 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
(28 Dec, 29 Dec, 30 Dec).

IIA.  Geophysical Activity Summary 26/2100Z to 27/2100Z: The geomagnetic
field has been at quiet to unsettled levels for the past 24 hours. Solar
wind speed slowly decreasing from about 500 km/s to 460 km/s levels.
Total IMF reached 6 nT at 27/1930Z. The maximum southward component of
Bz reached -5 nT at 27/1841Z.  Electrons greater than 2 MeV at
geosynchronous orbit reached a peak level of 6,123 pfu.
IIB.  Geophysical Activity Forecast: The geomagnetic field is expected
to be at quiet levels on days one, two, and three (28 Dec, 29 Dec, 30
Dec). Protons have a slight chance of crossing threshold on day one (28
Dec) and have a slight chance of crossing threshold on days two and
three (29 Dec, 30 Dec).

III.  Event probabilities 28 Dec-30 Dec
Class M    65/65/65
Class X    20/20/20
Proton     15/10/10
PCAF       green

IV.  Penticton 10.7 cm Flux
Observed           27 Dec 178
Predicted   28 Dec-30 Dec 175/170/160
90 Day Mean        27 Dec 146

V.  Geomagnetic A Indices
Observed Afr/Ap 26 Dec  006/008
Estimated Afr/Ap 27 Dec  007/007
Predicted Afr/Ap 28 Dec-30 Dec  005/005-006/005-005/005

VI.  Geomagnetic Activity Probabilities 28 Dec-30 Dec
A.  Middle Latitudes
Active                10/10/10
Minor Storm           01/01/01
Major-severe storm    01/01/01
B.  High Latitudes
Active                15/15/15
Minor Storm           20/20/20
Major-severe storm    10/10/10
