:Product: 0913RSGA.txt
:Issued: 2026 Sep 13 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 256 Issued at 2200Z on 13 Sep 2026

IA.  Analysis of Solar Active Regions and Activity from 12/2100Z to
13/2100Z: Solar activity has been at very low 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 (14 Sep,
15 Sep, 16 Sep).

IIA.  Geophysical Activity Summary 12/2100Z to 13/2100Z: The geomagnetic
field has been at quiet to unsettled levels for the past 24 hours. Solar
wind speed reached a peak of 461 km/s at 13/1541Z. Total IMF reached 7
nT at 13/0022Z. The maximum southward component of Bz reached 6 nT at
13/0125Z.  Electrons greater than 2 MeV at geosynchronous orbit reached
a peak level of 1827 pfu.
IIB.  Geophysical Activity Forecast: The geomagnetic field is expected
to be at unsettled to active levels on day one (14 Sep), quiet to active
levels on day two (15 Sep) and unsettled to minor storm levels on day
three (16 Sep).

III.  Event probabilities 14 Sep-16 Sep
Class M    10/10/10
Class X    01/01/01
Proton     01/01/01
PCAF       green

IV.  Penticton 10.7 cm Flux
Observed           13 Sep 114
Predicted   14 Sep-16 Sep 105/100/095
90 Day Mean        13 Sep 126

V.  Geomagnetic A Indices
Observed Afr/Ap 12 Sep  006/007
Estimated Afr/Ap 13 Sep  009/010
Predicted Afr/Ap 14 Sep-16 Sep  014/018-013/016-017/020

VI.  Geomagnetic Activity Probabilities 14 Sep-16 Sep
A.  Middle Latitudes
Active                25/25/35
Minor Storm           05/05/10
Major-severe storm    01/01/01
B.  High Latitudes
Active                15/15/20
Minor Storm           20/20/20
Major-severe storm    20/20/20