:Product: 0917RSGA.txt
:Issued: 2025 Sep 17 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 260 Issued at 2200Z on 17 Sep 2025

IA.  Analysis of Solar Active Regions and Activity from 16/2100Z to
17/2100Z: Solar activity has been at low levels for the past 24 hours.
There are currently 6 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 (18 Sep, 19 Sep,
20 Sep).

IIA.  Geophysical Activity Summary 16/2100Z to 17/2100Z: The geomagnetic
field has been at quiet to unsettled levels for the past 24 hours. Solar
wind speed reached a peak of 872 km/s at 17/0843Z. Total IMF reached 5
nT at 17/0008Z. The maximum southward component of Bz reached -4 nT at
17/0704Z.  Electrons greater than 2 MeV at geosynchronous orbit reached
a peak level of 4335 pfu.
IIB.  Geophysical Activity Forecast: The geomagnetic field is expected
to be at quiet to unsettled levels on day one (18 Sep) and quiet levels
on days two and three (19 Sep, 20 Sep).

III.  Event probabilities 18 Sep-20 Sep
Class M    35/35/35
Class X    01/01/01
Proton     01/01/01
PCAF       green

IV.  Penticton 10.7 cm Flux
Observed           17 Sep 147
Predicted   18 Sep-20 Sep 148/150/150
90 Day Mean        17 Sep 144

V.  Geomagnetic A Indices
Observed Afr/Ap 16 Sep  017/021
Estimated Afr/Ap 17 Sep  010/011
Predicted Afr/Ap 18 Sep-20 Sep  009/010-006/005-006/005

VI.  Geomagnetic Activity Probabilities 18 Sep-20 Sep
A.  Middle Latitudes
Active                20/10/10
Minor Storm           05/01/01
Major-severe storm    01/01/01
B.  High Latitudes
Active                15/15/15
Minor Storm           25/20/20
Major-severe storm    30/20/20
