:Product: 1222RSGA.txt
:Issued: 2021 Dec 22 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 356 Issued at 2200Z on 22 Dec 2021

IA.  Analysis of Solar Active Regions and Activity from 21/2100Z to
22/2100Z: Solar activity has been at moderate levels for the past 24
hours. The largest solar event of the period was a M1 event observed at
22/0706Z from Region 2908 (S20W39). There are currently 9 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
days one, two, and three (23 Dec, 24 Dec, 25 Dec).

IIA.  Geophysical Activity Summary 21/2100Z to 22/2100Z: The geomagnetic
field has been at quiet to unsettled levels for the past 24 hours. Solar
wind speed reached a peak of 604 km/s at 22/1215Z. Total IMF reached 6
nT at 22/0104Z. The maximum southward component of Bz reached -4 nT at
22/0230Z.  Electrons greater than 2 MeV at geosynchronous orbit reached
a peak level of 1189 pfu.
IIB.  Geophysical Activity Forecast: The geomagnetic field is expected
to be at quiet to active levels on day one (23 Dec), quiet to minor
storm levels on day two (24 Dec) and quiet to unsettled levels on day
three (25 Dec). Protons have a slight chance of crossing threshold on
days one, two, and three (23 Dec, 24 Dec, 25 Dec).

III.  Event probabilities 23 Dec-25 Dec
Class M    25/25/25
Class X    10/10/10
Proton     10/10/10
PCAF       green

IV.  Penticton 10.7 cm Flux
Observed           22 Dec 140
Predicted   23 Dec-25 Dec 140/140/138
90 Day Mean        22 Dec 090

V.  Geomagnetic A Indices
Observed Afr/Ap 21 Dec  007/008
Estimated Afr/Ap 22 Dec  011/012
Predicted Afr/Ap 23 Dec-25 Dec  012/016-016/020-009/008

VI.  Geomagnetic Activity Probabilities 23 Dec-25 Dec
A.  Middle Latitudes
Active                35/35/20
Minor Storm           20/25/05
Major-severe storm    05/05/01
B.  High Latitudes
Active                10/10/15
Minor Storm           25/25/25
Major-severe storm    55/65/30