:Product: 0818RSGA.txt
:Issued: 2023 Aug 18 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 230 Issued at 2200Z on 18 Aug 2023

IA.  Analysis of Solar Active Regions and Activity from 17/2100Z to
18/2100Z: 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
18/1930Z from Region 3409 (N20W42). There are currently 8 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 (19
Aug, 20 Aug, 21 Aug).

IIA.  Geophysical Activity Summary 17/2100Z to 18/2100Z: The geomagnetic
field has been at quiet to unsettled levels for the past 24 hours. Solar
wind speed reached a peak of 553 km/s at 18/1246Z. Total IMF reached 14
nT at 18/0208Z. The maximum southward component of Bz reached -11 nT at
18/0723Z.  Electrons greater than 2 MeV at geosynchronous orbit reached
a peak level of 157 pfu.
IIB.  Geophysical Activity Forecast: The geomagnetic field is expected
to be at quiet to active levels on day one (19 Aug) and quiet to
unsettled levels on days two and three (20 Aug, 21 Aug).

III.  Event probabilities 19 Aug-21 Aug
Class M    20/20/20
Class X    01/01/01
Proton     01/01/01
PCAF       green

IV.  Penticton 10.7 cm Flux
Observed           18 Aug 150 
Predicted   19 Aug-21 Aug 150/152/155
90 Day Mean        18 Aug 166 

V.  Geomagnetic A Indices
Observed Afr/Ap 17 Aug  010/007
Estimated Afr/Ap 18 Aug  010/011
Predicted Afr/Ap 19 Aug-21 Aug  010/010-008/008-006/008

VI.  Geomagnetic Activity Probabilities 19 Aug-21 Aug
A.  Middle Latitudes
Active                15/10/10
Minor Storm           05/01/01
Major-severe storm    01/01/01
B.  High Latitudes
Active                15/15/15
Minor Storm           20/15/15
Major-severe storm    20/10/10