:Product: 0904RSGA.txt
:Issued: 2025 Sep 04 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 247 Issued at 2200Z on 04 Sep 2025

IA.  Analysis of Solar Active Regions and Activity from 03/2100Z to
04/2100Z: Solar activity has been at moderate levels for the past 24
hours. There are currently 10 numbered sunspot regions on the disk.
IB.  Solar Activity Forecast: Solar activity is likely to be moderate
with a slight chance for an X-class flare on days one and two (05 Sep,
06 Sep) and expected to be low with a chance for M-class flares on day
three (07 Sep).

IIA.  Geophysical Activity Summary 03/2100Z to 04/2100Z: The geomagnetic
field has been at quiet to unsettled levels for the past 24 hours. Solar
wind speed reached a peak of 675 km/s at 04/0412Z. Total IMF reached 9
nT at 03/2327Z. The maximum southward component of Bz reached -5 nT at
04/1421Z.  Electrons greater than 2 MeV at geosynchronous orbit reached
a peak level of 387 pfu.
IIB.  Geophysical Activity Forecast: The geomagnetic field is expected
to be at quiet to minor storm levels on days one and two (05 Sep, 06
Sep) and quiet to active levels on day three (07 Sep). Protons greater
than 10 Mev have a slight chance of crossing threshold on days one and
two (05 Sep, 06 Sep).

III.  Event probabilities 05 Sep-07 Sep
Class M    55/55/40
Class X    10/10/05
Proton     10/10/05
PCAF       green

IV.  Penticton 10.7 cm Flux
Observed           04 Sep 172
Predicted   05 Sep-07 Sep 168/162/158
90 Day Mean        04 Sep 145

V.  Geomagnetic A Indices
Observed Afr/Ap 03 Sep  008/008
Estimated Afr/Ap 04 Sep  008/010
Predicted Afr/Ap 05 Sep-07 Sep  013/018-020/025-012/015

VI.  Geomagnetic Activity Probabilities 05 Sep-07 Sep
A.  Middle Latitudes
Active                40/35/40
Minor Storm           30/30/15
Major-severe storm    05/10/01
B.  High Latitudes
Active                05/10/10
Minor Storm           20/25/25
Major-severe storm    65/60/55
