2026 Sep 10 2230 UTC
Joint USAF/NOAA Solar Geophysical Activity Report and Forecast
SDF Number 253 Issued at 2200Z on 10 Sep 2026

IA. Analysis of Solar Active Regions and Activity from 09/2100Z to
10/2100Z: Solar activity has been at low levels for the past 24 hours.
There are currently 7 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 day one (11 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 (12 Sep, 13 Sep).

IIA. Geophysical Activity Summary 09/2100Z to 10/2100Z: The geomagnetic
field has been at quiet to unsettled levels for the past 24 hours. Solar
wind speed reached a peak of 470 km/s at 10/1638Z. Total IMF reached 6
nT at 10/0100Z. The maximum southward component of Bz reached 4 nT at
10-2044Z. Electrons greater than 2 MeV at geosynchronous orbit reached a
peak level of 3077 pfu.
IIB. Geophysical Activity Forecast: The geomagnetic field is expected
to be at quiet to unsettled levels on days one, two, and three (11 Sep,
12 Sep, 13 Sep).

III. Event probabilities 11 Sep-13 Sep
Class M 10/10/10
Class X 01/01/01
Proton 01/01/01
PCAF green

IV. Penticton 10.7 cm Flux
Observed 10 Sep 115
Predicted 11 Sep-13 Sep 115/118/120
90 Day Mean 10 Sep 127

V. Geomagnetic A Indices
Observed Afr/Ap 09 Sep 010/012
Estimated Afr/Ap 10 Sep 008/009
Predicted Afr/Ap 11 Sep-13 Sep 008/010-009/008-007/010

VI. Geomagnetic Activity Probabilities 11 Sep-13 Sep
A. Middle Latitudes
Active 25/15/20
Minor Storm 05/05/05
Major-severe storm 01/01/01
B. High Latitudes
Active 15/15/15
Minor Storm 30/20/20
Major-severe storm 30/20/20