:Product: 1216RSGA.txt
:Issued: 2021 Dec 16 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 350 Issued at 2200Z on 16 Dec 2021

IA.  Analysis of Solar Active Regions and Activity from 15/2100Z to
16/2100Z: Solar activity has been at low levels for the past 24 hours.
The largest solar event of the period was a C3 event observed at
16/1527Z from Region 2909 (S21E58). There are currently 7 numbered
sunspot regions on the disk.
IB.  Solar Activity Forecast: Solar activity is expected to be low with
a chance for M-class flares on day one (17 Dec) and likely to be low
with a slight chance for an M-class flare on days two and three (18 Dec,
19 Dec).

IIA.  Geophysical Activity Summary 15/2100Z to 16/2100Z: The geomagnetic
field has been at quiet to unsettled levels for the past 24 hours. Solar
wind speed reached a peak of 558 km/s at 16/1123Z. Total IMF reached 7
nT at 16/0932Z. The maximum southward component of Bz reached -5 nT at
16/0942Z.  Electrons greater than 2 MeV at geosynchronous orbit reached
a peak level of 154 pfu.
IIB.  Geophysical Activity Forecast: The geomagnetic field is expected
to be at quiet to unsettled levels on day one (17 Dec) and quiet levels
on days two and three (18 Dec, 19 Dec).

III.  Event probabilities 17 Dec-19 Dec
Class M    25/20/15
Class X    05/01/01
Proton     01/01/01
PCAF       green

IV.  Penticton 10.7 cm Flux
Observed           16 Dec 118
Predicted   17 Dec-19 Dec 118/118/118
90 Day Mean        16 Dec 087

V.  Geomagnetic A Indices
Observed Afr/Ap 15 Dec  008/006
Estimated Afr/Ap 16 Dec  009/008
Predicted Afr/Ap 17 Dec-19 Dec  008/008-006/005-006/005

VI.  Geomagnetic Activity Probabilities 17 Dec-19 Dec
A.  Middle Latitudes
Active                15/10/10
Minor Storm           05/01/01
Major-severe storm    01/01/01
B.  High Latitudes
Active                15/15/15
Minor Storm           25/20/20
Major-severe storm    25/20/15