:Product: Report of Solar-Geophysical Activity
:Issued: 2026 May 25 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 145 Issued at 2200Z on 25 May 2026

IA.  Analysis of Solar Active Regions and Activity from 24/2100Z to
25/2100Z: 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 chance for M-class flares on days one, two, and three (26 May, 27 May,
28 May).

IIA.  Geophysical Activity Summary 24/2100Z to 25/2100Z: The geomagnetic
field has been at quiet to unsettled levels for the past 24 hours. Solar
wind speed reached a peak of 438 km/s at 25/1820Z. Total IMF reached 9
nT at 25/1637Z. The maximum southward component of Bz reached -7 nT at
25/0709Z.  Electrons greater than 2 MeV at geosynchronous orbit reached
a peak level of 748 pfu.
IIB.  Geophysical Activity Forecast: The geomagnetic field is expected
to be at quiet levels on day one (26 May) and quiet to active levels on
days two and three (27 May, 28 May).

III.  Event probabilities 26 May-28 May
Class M    35/35/35
Class X    05/05/05
Proton     05/05/05
PCAF       green

IV.  Penticton 10.7 cm Flux
Observed           25 May 139
Predicted   26 May-28 May 142/145/150
90 Day Mean        25 May 125

V.  Geomagnetic A Indices
Observed Afr/Ap 24 May  007/006
Estimated Afr/Ap 25 May  006/006
Predicted Afr/Ap 26 May-28 May  007/006-010/012-011/012

VI.  Geomagnetic Activity Probabilities 26 May-28 May
A.  Middle Latitudes
Active                10/25/25
Minor Storm           05/10/10
Major-severe storm    01/01/01
B.  High Latitudes
Active                20/20/20
Minor Storm           25/35/35
Major-severe storm    20/30/30