:Product: Report of Solar-Geophysical Activity
:Issued: 2025 Apr 28 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 118 Issued at 2200Z on 28 Apr 2025

IA.  Analysis of Solar Active Regions and Activity from 27/2100Z to
28/2100Z: Solar activity has been at low levels for the past 24 hours.
There are currently 10 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 (29
Apr, 30 Apr, 01 May).

IIA.  Geophysical Activity Summary 27/2100Z to 28/2100Z: The geomagnetic
field has been at quiet to unsettled levels for the past 24 hours. Solar
wind speed reached a peak of 535 km/s at 28/0705Z. Total IMF reached 9
nT at 28/0715Z. The maximum southward component of Bz reached -7 nT at
27/2225Z.  Electrons greater than 2 MeV at geosynchronous orbit reached
a peak level of 631 pfu.
IIB.  Geophysical Activity Forecast: The geomagnetic field is expected
to be at quiet to unsettled levels on day one (29 Apr) and quiet levels
on days two and three (30 Apr, 01 May).

III.  Event probabilities 29 Apr-01 May
Class M    15/15/20
Class X    01/01/01
Proton     01/01/01
PCAF       green

IV.  Penticton 10.7 cm Flux
Observed           28 Apr 154
Predicted   29 Apr-01 May 155/155/160
90 Day Mean        28 Apr 171

V.  Geomagnetic A Indices
Observed Afr/Ap 27 Apr  007/ 006
Estimated Afr/Ap 28 Apr  006/007
Predicted Afr/Ap 29 Apr-01 May  007/008-006/005-005/005

VI.  Geomagnetic Activity Probabilities 29 Apr-01 May
A.  Middle Latitudes
Active                20/10/10
Minor Storm           05/01/01
Major-severe storm    01/01/01
B.  High Latitudes
Active                15/15/15
Minor Storm           25/20/20
Major-severe storm    30/20/20