:Product: 0920RSGA.txt
:Issued: 2023 Sep 20 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 263 Issued at 2200Z on 20 Sep 2023

IA.  Analysis of Solar Active Regions and Activity from 19/2100Z to
20/2100Z: Solar activity has been at high levels for the past 24 hours.
The largest solar event of the period was a M8 event observed at
20/1419Z from Region 3435 (N09E29). There are currently 11 numbered
sunspot regions on the disk.
IB.  Solar Activity Forecast: Solar activity is likely to be moderate on
days one, two, and three (21 Sep, 22 Sep, 23 Sep).

IIA.  Geophysical Activity Summary 19/2100Z to 20/2100Z: The geomagnetic
field has been at quiet to active levels for the past 24 hours. Solar
wind speed reached a peak of 567 km/s at 19/2211Z. Total IMF reached 10
nT at 20/0548Z. The maximum southward component of Bz reached -4 nT at
20/0859Z.  Electrons greater than 2 MeV at geosynchronous orbit reached
a peak level of 2923 pfu.
IIB.  Geophysical Activity Forecast: The geomagnetic field is expected
to be at quiet to unsettled levels on days one and three (21 Sep, 23
Sep) and quiet to active levels on day two (22 Sep).

III.  Event probabilities 21 Sep-23 Sep
Class M    55/55/55
Class X    05/05/05
Proton     05/05/05
PCAF       green

IV.  Penticton 10.7 cm Flux
Observed           20 Sep 156
Predicted   21 Sep-23 Sep 155/152/153
90 Day Mean        20 Sep 161

V.  Geomagnetic A Indices
Observed Afr/Ap 19 Sep  038/038
Estimated Afr/Ap 20 Sep  012/016
Predicted Afr/Ap 21 Sep-23 Sep  008/008-011/015-011/012

VI.  Geomagnetic Activity Probabilities 21 Sep-23 Sep
A.  Middle Latitudes
Active                20/35/30
Minor Storm           05/15/15
Major-severe storm    01/01/01
B.  High Latitudes
Active                15/10/10
Minor Storm           20/30/25
Major-severe storm    20/50/50