:Product: 1227RSGA.txt
:Issued: 2021 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 2021

IA.  Analysis of Solar Active Regions and Activity from 26/2100Z to
27/2100Z: Solar activity has been at low levels for the past 24 hours.
The largest solar event of the period was a C1 event observed at
27/0227Z. There are currently 4 numbered sunspot regions on the disk.
IB.  Solar Activity Forecast: Solar activity is expected to be low with
a slight chance for an M-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 active levels for the past 24 hours. Solar
wind speed reached a peak of 507 km/s at 26/2213Z. Total IMF reached 15
nT at 27/1359Z. The maximum southward component of Bz reached -10 nT at
27/1050Z.  Electrons greater than 2 MeV at geosynchronous orbit reached
a peak level of 3210 pfu.
IIB.  Geophysical Activity Forecast: The geomagnetic field is expected
to be at quiet to unsettled levels on days one and three (28 Dec, 30
Dec) and quiet to active levels on day two (29 Dec).

III.  Event probabilities 28 Dec-30 Dec
Class M    20/20/20
Class X    01/01/01
Proton     01/01/01
PCAF       green

IV.  Penticton 10.7 cm Flux
Observed           27 Dec 124
Predicted   28 Dec-30 Dec 125/122/120
90 Day Mean        27 Dec 092

V.  Geomagnetic A Indices
Observed Afr/Ap 26 Dec  002/003
Estimated Afr/Ap 27 Dec  007/008
Predicted Afr/Ap 28 Dec-30 Dec  010/010-011/012-007/010

VI.  Geomagnetic Activity Probabilities 28 Dec-30 Dec
A.  Middle Latitudes
Active                25/35/25
Minor Storm           05/15/05
Major-severe storm    01/01/01
B.  High Latitudes
Active                15/15/15
Minor Storm           30/30/30
Major-severe storm    30/45/30