:Product: 0828RSGA.txt
:Issued: 2021 Aug 28 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 240 Issued at 2200Z on 28 Aug 2021

IA.  Analysis of Solar Active Regions and Activity from 27/2100Z to
28/2100Z: Solar activity has been at moderate levels for the past 24
hours. The largest solar event of the period was a M4 event observed at
28/0611Z from Region 2860 (S29W10). 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 on days one, two, and three (29 Aug, 30 Aug,
31 Aug).

IIA.  Geophysical Activity Summary 27/2100Z to 28/2100Z: The geomagnetic
field has been at quiet to minor storm levels for the past 24 hours.
Solar wind speed reached a peak of 389 km/s at 28/1718Z. Total IMF
reached 14 nT at 27/2100Z. The maximum southward component of Bz reached
-12 nT at 27/2131Z.  Electrons greater than 2 MeV at geosynchronous
orbit reached a peak level of 10655 pfu.
IIB.  Geophysical Activity Forecast: The geomagnetic field is expected
to be at quiet to minor storm levels on days one and two (29 Aug, 30
Aug) and quiet levels on day three (31 Aug).

III.  Event probabilities 29 Aug-31 Aug
Class M    30/30/30
Class X    05/05/05
Proton     01/01/01
PCAF       green

IV.  Penticton 10.7 cm Flux
Observed           28 Aug 090
Predicted   29 Aug-31 Aug 090/090/090
90 Day Mean        28 Aug 079

V.  Geomagnetic A Indices
Observed Afr/Ap 27 Aug  019/021
Estimated Afr/Ap 28 Aug  013/016
Predicted Afr/Ap 29 Aug-31 Aug  011/018-022/025-007/008

VI.  Geomagnetic Activity Probabilities 29 Aug-31 Aug
A.  Middle Latitudes
Active                35/30/20
Minor Storm           35/40/05
Major-severe storm    20/25/01
B.  High Latitudes
Active                05/05/15
Minor Storm           20/15/30
Major-severe storm    75/80/30