:Product: Report of Solar-Geophysical Activity
:Issued: 2021 Sep 23 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 266 Issued at 2200Z on 23 Sep 2021

IA.  Analysis of Solar Active Regions and Activity from 22/2100Z to
23/2100Z: Solar activity has been at very low levels for the past 24
hours. There are currently 5 numbered sunspot regions on the disk.
IB.  Solar Activity Forecast: Solar activity is likely to be low with a
slight chance for an M-class flare on days one, two, and three (24 Sep,
25 Sep, 26 Sep).

IIA.  Geophysical Activity Summary 22/2100Z to 23/2100Z: The geomagnetic
field has been at quiet to active levels for the past 24 hours. Solar
wind speed reached a peak of 404 km/s at 23/1621Z. Total IMF reached 9
nT at 23/2056Z. The maximum southward component of Bz reached -5 nT at
23/0518Z.  Electrons greater than 2 MeV at geosynchronous orbit reached
a peak level of 1247 pfu.
IIB.  Geophysical Activity Forecast: The geomagnetic field is expected
to be at quiet to active levels on day one (24 Sep), quiet to unsettled
levels on day two (25 Sep) and quiet to minor storm levels on day three
(26 Sep).

III.  Event probabilities 24 Sep-26 Sep
Class M    15/15/15
Class X    01/01/01
Proton     01/01/01
PCAF       green

IV.  Penticton 10.7 cm Flux
Observed           23 Sep 090
Predicted   24 Sep-26 Sep 090/092/095
90 Day Mean        23 Sep 082

V.  Geomagnetic A Indices
Observed Afr/Ap 22 Sep  011/012
Estimated Afr/Ap 23 Sep  010/011
Predicted Afr/Ap 24 Sep-26 Sep  011/015-007/008-012/020

VI.  Geomagnetic Activity Probabilities 24 Sep-26 Sep
A.  Middle Latitudes
Active                30/35/45
Minor Storm           10/15/30
Major-severe storm    01/01/05
B.  High Latitudes
Active                15/15/05
Minor Storm           30/30/20
Major-severe storm    40/50/75