:Product: 0921RSGA.txt
:Issued: 2025 Sep 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 264 Issued at 2200Z on 21 Sep 2025

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.
There are currently 10 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 (22 Sep, 23 Sep,
24 Sep).

IIA.  Geophysical Activity Summary 20/2100Z to 21/2100Z: The geomagnetic
field has been at quiet levels for the past 24 hours. Solar wind speed
reached a peak of 354 km/s at 21/0844Z. Total IMF reached 7 nT at
21/2021Z. The maximum southward component of Bz reached -4 nT at
21/1304Z.  Electrons greater than 2 MeV at geosynchronous orbit reached
a peak level of 4819 pfu.
IIB.  Geophysical Activity Forecast: The geomagnetic field is expected
to be at unsettled to minor storm levels on day one (22 Sep), quiet to
unsettled levels on day two (23 Sep) and quiet levels on day three (24
Sep).

III.  Event probabilities 22 Sep-24 Sep
Class M    40/40/40
Class X    05/05/05
Proton     05/05/05
PCAF       green

IV.  Penticton 10.7 cm Flux
Observed           21 Sep 176
Predicted   22 Sep-24 Sep 180/180/185
90 Day Mean        21 Sep 146

V.  Geomagnetic A Indices
Observed Afr/Ap 20 Sep  005/005
Estimated Afr/Ap 21 Sep  008/010
Predicted Afr/Ap 22 Sep-24 Sep  019/024-009/012-005/005

VI.  Geomagnetic Activity Probabilities 22 Sep-24 Sep
A.  Middle Latitudes
Active                40/20/10
Minor Storm           25/05/01
Major-severe storm    05/01/01
B.  High Latitudes
Active                10/15/15
Minor Storm           25/25/20
Major-severe storm    60/25/20
