:Product: Report of Solar-Geophysical Activity
:Issued: 2026 Sep 05 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 248 Issued at 2200Z on 05 Sep 2026

IA.  Analysis of Solar Active Regions and Activity from 04/2100Z to
05/2100Z: Solar activity has been at moderate levels for the past 24
hours. There are currently 6 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 (06 Sep,
07 Sep, 08 Sep).

IIA.  Geophysical Activity Summary 04/2100Z to 05/2100Z: The geomagnetic
field has been at quiet to unsettled levels for the past 24 hours. Solar
wind speed reached a peak of 372 km/s at 05/1619Z. Total IMF reached 5
nT at 05/1859Z. The maximum southward component of Bz reached 5 nT at
05/0328Z. Protons greater than 10 MeV at geosynchronous orbit reached a
peak level of 17 pfu at 05/1645Z. Electrons greater than 2 MeV at
geosynchronous orbit reached a peak level of 641 pfu.

IIB.  Geophysical Activity Forecast: The geomagnetic field is expected
to be at quiet levels on day one (06 Sep), quiet to active levels on day
two (07 Sep) and quiet to unsettled levels on day three (08 Sep).
Protons are expected to cross threshold on day one (06 Sep) and have a
slight chance of crossing threshold on days two and three (07 Sep, 08
Sep).

III.  Event probabilities 06 Sep-08 Sep
Class M    20/20/20
Class X    01/01/01
Proton     99/10/10
PCAF       yellow

IV.  Penticton 10.7 cm Flux
Observed           05 Sep 111
Predicted   06 Sep-08 Sep 108/105/105
90 Day Mean        05 Sep 128

V.  Geomagnetic A Indices
Observed Afr/Ap 04 Sep  004/004
Estimated Afr/Ap 05 Sep  008/008
Predicted Afr/Ap 06 Sep-08 Sep  006/005-013/015-008/018

VI.  Geomagnetic Activity Probabilities 06 Sep-08 Sep
A.  Middle Latitudes
Active                10/30/15
Minor Storm           01/10/05
Major-severe storm    01/01/01
B.  High Latitudes
Active                15/15/15
Minor Storm           15/20/20
Major-severe storm    15/25/20