:Product: 0928RSGA.txt
:Issued: 2026 Sep 28 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 271 Issued at 2200Z on 28 Sep 2026

IA.  Analysis of Solar Active Regions and Activity from 27/2100Z to
28/2100Z: Solar activity has been at very low levels for the past 24
hours. There are currently 3 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 and a slight chance for an M-class
flare on days one, two, and three (29 Sep, 30 Sep, 01 Oct).

IIA.  Geophysical Activity Summary 27/2100Z to 28/2100Z: The geomagnetic
field has been at quiet levels for the past 24 hours. Solar wind speed
reached a peak of 383 km/s at 27/2114Z. Total IMF reached 4 nT at
28/0158Z. The maximum southward component of Bz reached -2 nT at
28/0157Z.  Electrons greater than 2 MeV at geosynchronous orbit reached
a peak level of 4128 pfu.
IIB.  Geophysical Activity Forecast: The geomagnetic field is expected
to be at quiet levels on days one, two, and three (29 Sep, 30 Sep, 01
Oct).

III.  Event probabilities 29 Sep-01 Oct
Class M    10/10/10
Class X    01/01/01
Proton     01/01/01
PCAF       green

IV.  Penticton 10.7 cm Flux
Observed           28 Sep 095
Predicted   29 Sep-01 Oct 095/100/100
90 Day Mean        28 Sep 120

V.  Geomagnetic A Indices
Observed Afr/Ap 27 Sep  008/009
Estimated Afr/Ap 28 Sep  005/005
Predicted Afr/Ap 29 Sep-01 Oct  006/005-006/005-006/005

VI.  Geomagnetic Activity Probabilities 29 Sep-01 Oct
A.  Middle Latitudes
Active                10/10/10
Minor Storm           01/05/05
Major-severe storm    01/01/01
B.  High Latitudes
Active                15/15/15
Minor Storm           15/25/15
Major-severe storm    15/20/15