:Product: 1224RSGA.txt
:Issued: 2021 Dec 24 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 358 Issued at 2200Z on 24 Dec 2021

IA.  Analysis of Solar Active Regions and Activity from 23/2100Z to
24/2100Z: Solar activity has been at low levels for the past 24 hours.
The largest solar event of the period was a C7 event observed at
24/0342Z from Region 2917 (S27E05). There are currently 8 numbered
sunspot regions on the disk.
IB.  Solar Activity Forecast: Solar activity is expected to be low with
a chance for M-class flares and a slight chance for an X-class flare on
day one (25 Dec) and expected to be low with a slight chance for an
M-class flare on day two (26 Dec) and expected to be very low with a
chance for a C-class flares on day three (27 Dec).

IIA.  Geophysical Activity Summary 23/2100Z to 24/2100Z: The geomagnetic
field has been at quiet levels for the past 24 hours. Solar wind speed
reached a peak of 525 km/s at 24/0131Z. Total IMF reached 5 nT at
24/1847Z. The maximum southward component of Bz reached -4 nT at
24/1928Z.  Electrons greater than 2 MeV at geosynchronous orbit reached
a peak level of 2017 pfu.
IIB.  Geophysical Activity Forecast: The geomagnetic field is expected
to be at quiet to active levels on days one and two (25 Dec, 26 Dec) and
quiet to unsettled levels on day three (27 Dec). Protons greater than 10
Mev have a slight chance of crossing threshold on day one (25 Dec).

III.  Event probabilities 25 Dec-27 Dec
Class M    25/10/05
Class X    10/01/01
Proton     10/01/01
PCAF       green

IV.  Penticton 10.7 cm Flux
Observed           24 Dec 126
Predicted   25 Dec-27 Dec 125/120/115
90 Day Mean        24 Dec 091

V.  Geomagnetic A Indices
Observed Afr/Ap 23 Dec  002/002
Estimated Afr/Ap 24 Dec  007/011
Predicted Afr/Ap 25 Dec-27 Dec  011/012-014/016-008/008

VI.  Geomagnetic Activity Probabilities 25 Dec-27 Dec
A.  Middle Latitudes
Active                30/30/25
Minor Storm           10/10/05
Major-severe storm    01/01/01
B.  High Latitudes
Active                15/15/15
Minor Storm           30/30/30
Major-severe storm    40/40/30