:Product: 0928RSGA.txt
:Issued: 2021 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 2021

IA.  Analysis of Solar Active Regions and Activity from 27/2100Z to
28/2100Z: Solar activity has been at low levels for the past 24 hours.
The largest solar event of the period was a C1 event observed at
28/0634Z. There are currently 4 numbered sunspot regions on the disk.
IB.  Solar Activity Forecast: Solar activity is expected to be very low
with a slight chance for a C-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 to unsettled levels for the past 24 hours. Solar
wind speed reached a peak of 548 km/s at 28/1209Z. Total IMF reached 13
nT at 27/2141Z. The maximum southward component of Bz reached -8 nT at
27/2235Z.  Electrons greater than 2 MeV at geosynchronous orbit reached
a peak level of 290 pfu.
IIB.  Geophysical Activity Forecast: The geomagnetic field is expected
to be at quiet to active levels on days one and two (29 Sep, 30 Sep) and
quiet to minor storm levels on day three (01 Oct).

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

IV.  Penticton 10.7 cm Flux
Observed           28 Sep 089
Predicted   29 Sep-01 Oct 088/084/082
90 Day Mean        28 Sep 082

V.  Geomagnetic A Indices
Observed Afr/Ap 27 Sep  006/006
Estimated Afr/Ap 28 Sep  010/010
Predicted Afr/Ap 29 Sep-01 Oct  009/010-011/012-018/024

VI.  Geomagnetic Activity Probabilities 29 Sep-01 Oct
A.  Middle Latitudes
Active                30/35/45
Minor Storm           10/10/30
Major-severe storm    01/01/05
B.  High Latitudes
Active                15/15/05
Minor Storm           30/30/20
Major-severe storm    40/45/70