:Product: 0916RSGA.txt
:Issued: 2026 Sep 16 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 259 Issued at 2200Z on 16 Sep 2026

IA.  Analysis of Solar Active Regions and Activity from 15/2100Z to
16/2100Z: Solar activity has been at very low levels for the past 24
hours. There are currently 2 numbered sunspot regions on the disk.
IB.  Solar Activity Forecast: Solar activity is expected to be very low
with a chance for a C-class flares on days one, two, and three (17 Sep,
18 Sep, 19 Sep).

IIA.  Geophysical Activity Summary 15/2100Z to 16/2100Z: The geomagnetic
field has been at quiet to active levels for the past 24 hours. Solar
wind speed reached a peak of 574 km/s at 16/0132 UTC. Total IMF reached
14 nT at 16/0019 UTC. The maximum southward component of Bz reached -9
nT at 15/2323 UTC.  Electrons greater than 2 MeV at geosynchronous orbit
reached a peak level of 533 pfu.
IIB.  Geophysical Activity Forecast: The geomagnetic field is expected
to be at unsettled to minor storm levels on day one (17 Sep), quiet to
active levels on day two (18 Sep) and quiet to unsettled levels on day
three (19 Sep).

III.  Event probabilities 17 Sep-19 Sep
Class M    05/05/05
Class X    01/01/01
Proton     01/01/01
PCAF       green

IV.  Penticton 10.7 cm Flux
Observed           16 Sep 100
Predicted   17 Sep-19 Sep 100/100/095
90 Day Mean        16 Sep 126

V.  Geomagnetic A Indices
Observed Afr/Ap 15 Sep  007/008
Estimated Afr/Ap 16 Sep  014/018
Predicted Afr/Ap 17 Sep-19 Sep  018/022-010/012-007/010

VI.  Geomagnetic Activity Probabilities 17 Sep-19 Sep
A.  Middle Latitudes
Active                40/20/15
Minor Storm           10/05/05
Major-severe storm    01/01/01
B.  High Latitudes
Active                15/15/15
Minor Storm           20/20/20
Major-severe storm    20/25/20