:Product: 0917RSGA.txt
:Issued: 2023 Sep 17 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 260 Issued at 2200Z on 17 Sep 2023

IA.  Analysis of Solar Active Regions and Activity from 16/2100Z to
17/2100Z: Solar activity has been at low levels for the past 24 hours.
The largest solar event of the period was a C3 event observed at
17/1604Z from Region 3435 (N10E60). There are currently 5 numbered
sunspot regions on the disk.
IB.  Solar Activity Forecast: Solar activity is expected to be low with
a slight chance for an M-class flare on days one, two, and three (18
Sep, 19 Sep, 20 Sep).

IIA.  Geophysical Activity Summary 16/2100Z to 17/2100Z: The geomagnetic
field has been at unsettled to active levels for the past 24 hours.
Solar wind speed reached a peak of 508 km/s at 17/0424Z. Total IMF
reached 11 nT at 17/0412Z. The maximum southward component of Bz reached
-8 nT at 17/0205Z.  Electrons greater than 2 MeV at geosynchronous orbit
reached a peak level of 167 pfu.
IIB.  Geophysical Activity Forecast: The geomagnetic field is expected
to be at quiet to unsettled levels on day one (18 Sep), unsettled to
major storm levels on day two (19 Sep) and quiet to active levels on day
three (20 Sep).

III.  Event probabilities 18 Sep-20 Sep
Class M    20/20/15
Class X    05/01/01
Proton     05/05/01
PCAF       green

IV.  Penticton 10.7 cm Flux
Observed           17 Sep 145
Predicted   18 Sep-20 Sep 145/140/140
90 Day Mean        17 Sep 162

V.  Geomagnetic A Indices
Observed Afr/Ap 16 Sep  005/010
Estimated Afr/Ap 17 Sep  014/019
Predicted Afr/Ap 18 Sep-20 Sep  008/008-022/035-014/015

VI.  Geomagnetic Activity Probabilities 18 Sep-20 Sep
A.  Middle Latitudes
Active                20/25/25
Minor Storm           05/40/05
Major-severe storm    01/35/01
B.  High Latitudes
Active                15/05/15
Minor Storm           25/20/20
Major-severe storm    35/75/25