:Product: 0820RSGA.txt
:Issued: 2026 Aug 20 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 232 Issued at 2200Z on 20 Aug 2026

IA.  Analysis of Solar Active Regions and Activity from 19/2100Z to
20/2100Z: Solar activity has been at high levels for the past 24 hours.
There are currently 4 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 (21 Aug, 22 Aug, 23 Aug).

IIA.  Geophysical Activity Summary 19/2100Z to 20/2100Z: The geomagnetic
field has been at quiet to unsettled levels for the past 24 hours. Solar
wind speed reached a peak of 598 km/s. Total IMF reached 6 nT. The
maximum southward component of Bz reached -5 nT.  Electrons greater than
2 MeV at geosynchronous orbit reached a peak level of 863 pfu.
IIB.  Geophysical Activity Forecast: The geomagnetic field is expected
to be at quiet to active levels on days one and two (21 Aug, 22 Aug) and
quiet to unsettled levels on day three (23 Aug).

III.  Event probabilities 21 Aug-23 Aug
Class M    40/40/40
Class X    10/10/10
Proton     05/05/05
PCAF       green

IV.  Penticton 10.7 cm Flux
Observed           20 Aug 125
Predicted   21 Aug-23 Aug 125/120/120
90 Day Mean        20 Aug 132

V.  Geomagnetic A Indices
Observed Afr/Ap 19 Aug  015/020
Estimated Afr/Ap 20 Aug  010/013
Predicted Afr/Ap 21 Aug-23 Aug  011/012-009/010-008/008

VI.  Geomagnetic Activity Probabilities 21 Aug-23 Aug
A.  Middle Latitudes
Active                30/25/25
Minor Storm           10/05/05
Major-severe storm    01/01/01
B.  High Latitudes
Active                15/15/20
Minor Storm           30/30/30
Major-severe storm    35/30/25