:Product: 1219RSGA.txt
:Issued: 2025 Dec 19 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 353 Issued at 2200Z on 19 Dec 2025

IA.  Analysis of Solar Active Regions and Activity from 18/2100Z to
19/2100Z: Solar activity has been at moderate levels for the past 24
hours. There are currently 3 numbered sunspot regions on the disk.
IB.  Solar Activity Forecast: Solar activity is likely to be low on days
one, two, and three (20 Dec, 21 Dec, 22 Dec).

IIA.  Geophysical Activity Summary 18/2100Z to 19/2100Z: The geomagnetic
field has been at quiet to unsettled levels for the past 24 hours. Solar
wind speed reached a peak of 906 km/s at 18/2313Z. Total IMF reached 5
nT at 19/0537Z. The maximum southward component of Bz reached -4 nT at
19/0054Z.  Electrons greater than 2 MeV at geosynchronous orbit reached
a peak level of 3239 pfu.
IIB.  Geophysical Activity Forecast: The geomagnetic field is expected
to be at quiet to unsettled levels on day one (20 Dec), quiet levels on
day two (21 Dec) and quiet to minor storm levels on day three (22 Dec).

III.  Event probabilities 20 Dec-22 Dec
Class M    05/05/05
Class X    01/01/01
Proton     01/01/01
PCAF       green

IV.  Penticton 10.7 cm Flux
Observed           19 Dec 118
Predicted   20 Dec-22 Dec 118/116/116
90 Day Mean        19 Dec 149

V.  Geomagnetic A Indices
Observed Afr/Ap 18 Dec  011/017
Estimated Afr/Ap 19 Dec  006/007
Predicted Afr/Ap 20 Dec-22 Dec  008/008-005/005-014/018

VI.  Geomagnetic Activity Probabilities 20 Dec-22 Dec
A.  Middle Latitudes
Active                20/10/35
Minor Storm           05/01/30
Major-severe storm    01/01/10
B.  High Latitudes
Active                15/15/10
Minor Storm           25/20/25
Major-severe storm    25/10/65
