:Product: 0818RSGA.txt
:Issued: 2025 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 2025

IA.  Analysis of Solar Active Regions and Activity from 17/2100Z to
18/2100Z: Solar activity has been at very low levels for the past 24
hours. There are currently 6 numbered sunspot regions on the disk.
IB.  Solar Activity Forecast: Solar activity is expected to be very low
with a chance for a C-class flares on days one and two (19 Aug, 20 Aug)
and likely to be low with a slight chance for an M-class flare on day
three (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 414 km/s at 18/0603Z. Total IMF reached 11
nT at 18/1036Z. The maximum southward component of Bz reached -7 nT at
18/1058Z.  Electrons greater than 2 MeV at geosynchronous orbit reached
a peak level of 2222 pfu.
IIB.  Geophysical Activity Forecast: The geomagnetic field is expected
to be at unsettled to minor storm levels on days one and two (19 Aug, 20
Aug) and quiet to active levels on day three (21 Aug).

III.  Event probabilities 19 Aug-21 Aug
Class M    05/05/10
Class X    01/01/01
Proton     01/01/01
PCAF       green

IV.  Penticton 10.7 cm Flux
Observed           18 Aug 114
Predicted   19 Aug-21 Aug 112/108/110
90 Day Mean        18 Aug 136

V.  Geomagnetic A Indices
Observed Afr/Ap 17 Aug  007/ 005
Estimated Afr/Ap 18 Aug  008/010
Predicted Afr/Ap 19 Aug-21 Aug  018/028-018/025-012/015

VI.  Geomagnetic Activity Probabilities 19 Aug-21 Aug
A.  Middle Latitudes
Active                35/35/30
Minor Storm           30/25/15
Major-severe storm    10/05/01
B.  High Latitudes
Active                05/10/15
Minor Storm           20/25/30
Major-severe storm    65/55/40
