:Product: 0817RSGA.txt
:Issued: 2025 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 2025

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.
There are currently 4 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 levels for the past 24 hours. Solar wind speed
reached a peak of 505 km/s at 17/0549Z. Total IMF reached 6 nT at
17/2026Z. The maximum southward component of Bz reached -4 nT at
17/1137Z.  Electrons greater than 2 MeV at geosynchronous orbit reached
a peak level of 8022 pfu.
IIB.  Geophysical Activity Forecast: The geomagnetic field is expected
to be at quiet to active levels on day one (18 Aug), unsettled to minor
storm levels on day two (19 Aug) and unsettled to active levels on day
three (20 Aug).

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

IV.  Penticton 10.7 cm Flux
Observed           17 Aug 117
Predicted   18 Aug-20 Aug 115/110/110
90 Day Mean        17 Aug 136

V.  Geomagnetic A Indices
Observed Afr/Ap 16 Aug  006/005
Estimated Afr/Ap 17 Aug  005/006
Predicted Afr/Ap 18 Aug-20 Aug  009/012-020/030-014/018

VI.  Geomagnetic Activity Probabilities 18 Aug-20 Aug
A.  Middle Latitudes
Active                35/45/35
Minor Storm           20/30/15
Major-severe storm    01/05/01
B.  High Latitudes
Active                10/05/10
Minor Storm           25/20/30
Major-severe storm    50/70/50
