:Product: Report of Solar-Geophysical Activity
:Issued: 2025 Apr 23 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 113 Issued at 2200Z on 23 Apr 2025

IA.  Analysis of Solar Active Regions and Activity from 22/2100Z to
23/2100Z: Solar activity has been at low levels for the past 24 hours.
There are currently 8 numbered sunspot regions on the disk.
IB.  Solar Activity Forecast: Solar activity is expected to be low with
a chance for M-class flares on days one, two, and three (24 Apr, 25 Apr,
26 Apr).

IIA.  Geophysical Activity Summary 22/2100Z to 23/2100Z: The geomagnetic
field has been at quiet to unsettled levels for the past 24 hours. Solar
wind speed reached a peak of 612 km/s at 22/2220Z. Total IMF reached 7
nT at 23/1955Z. The maximum southward component of Bz reached -3 nT at
23/0919Z.  Electrons greater than 2 MeV at geosynchronous orbit reached
a peak level of 690 pfu.
IIB.  Geophysical Activity Forecast: The geomagnetic field is expected
to be at quiet to active levels on days one and two (24 Apr, 25 Apr) and
quiet levels on day three (26 Apr).

III.  Event probabilities 24 Apr-26 Apr
Class M    40/40/40
Class X    01/01/01
Proton     01/01/01
PCAF       green

IV.  Penticton 10.7 cm Flux
Observed           23 Apr 167
Predicted   24 Apr-26 Apr 160/165/165
90 Day Mean        23 Apr 172

V.  Geomagnetic A Indices
Observed Afr/Ap 22 Apr  013/ NA
Estimated Afr/Ap 23 Apr  015/017
Predicted Afr/Ap 24 Apr-26 Apr  014/018-010/012-007/008

VI.  Geomagnetic Activity Probabilities 24 Apr-26 Apr
A.  Middle Latitudes
Active                30/30/15
Minor Storm           15/15/05
Major-severe storm    01/01/01
B.  High Latitudes
Active                15/15/15
Minor Storm           30/30/25
Major-severe storm    45/45/25