:Product: 0817RSGA.txt
:Issued: 2023 Aug 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 229 Issued at 2200Z on 17 Aug 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 C5 event observed at
17/1240Z from Region 3397 (N17W83). There are currently 9 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
Aug, 19 Aug, 20 Aug).

IIA.  Geophysical Activity Summary 16/2100Z to 17/2100Z: The geomagnetic
field has been at quiet to unsettled levels for the past 24 hours. Solar
wind speed reached a peak of 348 km/s at 17/1627Z. Total IMF reached 11
nT at 17/2030Z. The maximum southward component of Bz reached -6 nT at
17/1533Z.
IIB.  Geophysical Activity Forecast: The geomagnetic field is expected
to be at quiet to active levels on day one (18 Aug), quiet to unsettled
levels on day two (19 Aug) and quiet levels on day three (20 Aug).

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

IV.  Penticton 10.7 cm Flux
Observed           17 Aug 152
Predicted   18 Aug-20 Aug 150/155/157
90 Day Mean        17 Aug 167

V.  Geomagnetic A Indices
Observed Afr/Ap 16 Aug  010/012
Estimated Afr/Ap 17 Aug  009/010
Predicted Afr/Ap 18 Aug-20 Aug  010/012-007/008-006/005

VI.  Geomagnetic Activity Probabilities 18 Aug-20 Aug
A.  Middle Latitudes
Active                20/15/10
Minor Storm           05/05/01
Major-severe storm    01/01/01
B.  High Latitudes
Active                15/15/15
Minor Storm           20/20/15
Major-severe storm    20/20/10