:Product: 0831RSGA.txt
:Issued: 2021 Aug 31 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 243 Issued at 2200Z on 31 Aug 2021

IA.  Analysis of Solar Active Regions and Activity from 30/2100Z to
31/2100Z: 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
30/2134Z from Region 2860 (S29W36). There are currently 2 numbered
sunspot regions on the disk.
IB.  Solar Activity Forecast: Solar activity is expected to be very low
with a chance for a C-class or M-class flares on day one (01 Sep) and
expected to be very low with a chance for a C-class flares and a slight
chance for an M-class flare on days two and three (02 Sep, 03 Sep).

IIA.  Geophysical Activity Summary 30/2100Z to 31/2100Z: The geomagnetic
field has been at quiet to unsettled levels for the past 24 hours. Solar
wind speed reached a peak of 414 km/s at 30/2254Z. Total IMF reached 5
nT at 31/1208Z. The maximum southward component of Bz reached -4 nT at
31/1122Z.  Electrons greater than 2 MeV at geosynchronous orbit reached
a peak level of 3240 pfu.
IIB.  Geophysical Activity Forecast: The geomagnetic field is expected
to be at quiet to minor storm levels on day one (01 Sep), unsettled to
major storm levels on day two (02 Sep) and quiet to unsettled levels on
day three (03 Sep).

III.  Event probabilities 01 Sep-03 Sep
Class M    25/20/10
Class X    01/01/01
Proton     01/01/01
PCAF       green

IV.  Penticton 10.7 cm Flux
Observed           31 Aug 084
Predicted   01 Sep-03 Sep 082/082/082
90 Day Mean        31 Aug 079

V.  Geomagnetic A Indices
Observed Afr/Ap 30 Aug  009/008
Estimated Afr/Ap 31 Aug  009/009
Predicted Afr/Ap 01 Sep-03 Sep  016/018-023/030-010/012

VI.  Geomagnetic Activity Probabilities 01 Sep-03 Sep
A.  Middle Latitudes
Active                40/35/30
Minor Storm           25/30/10
Major-severe storm    05/10/01
B.  High Latitudes
Active                10/10/15
Minor Storm           25/25/30
Major-severe storm    65/65/40