:Product: 0821RSGA.txt
:Issued: 2023 Aug 21 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 233 Issued at 2200Z on 21 Aug 2023

IA.  Analysis of Solar Active Regions and Activity from 20/2100Z to
21/2100Z: Solar activity has been at low levels for the past 24 hours.
The largest solar event of the period was a C4 event observed at
21/0753Z. There are currently 8 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 (22
Aug, 23 Aug, 24 Aug).

IIA.  Geophysical Activity Summary 20/2100Z to 21/2100Z: The geomagnetic
field has been at quiet to unsettled levels for the past 24 hours. Solar
wind speed reached a peak of 686 km/s at 20/2240Z. Total IMF reached 7
nT at 20/2252Z. The maximum southward component of Bz reached -5 nT at
21/0723Z.  Electrons greater than 2 MeV at geosynchronous orbit reached
a peak level of 229 pfu.
IIB.  Geophysical Activity Forecast: The geomagnetic field is expected
to be at quiet to unsettled levels on days one, two, and three (22 Aug,
23 Aug, 24 Aug).

III.  Event probabilities 22 Aug-24 Aug
Class M    15/15/15
Class X    01/01/01
Proton     01/01/01
PCAF       green

IV.  Penticton 10.7 cm Flux
Observed           21 Aug 149
Predicted   22 Aug-24 Aug 150/155/155
90 Day Mean        21 Aug 166

V.  Geomagnetic A Indices
Observed Afr/Ap 20 Aug  012/011
Estimated Afr/Ap 21 Aug  008/010
Predicted Afr/Ap 22 Aug-24 Aug  008/010-008/010-007/010

VI.  Geomagnetic Activity Probabilities 22 Aug-24 Aug
A.  Middle Latitudes
Active                15/15/15
Minor Storm           05/05/05
Major-severe storm    01/01/01
B.  High Latitudes
Active                15/15/15
Minor Storm           20/20/20
Major-severe storm    20/20/20