:Product: Report of Solar-Geophysical Activity
:Issued: 2026 May 22 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 142 Issued at 2200Z on 22 May 2026

IA.  Analysis of Solar Active Regions and Activity from 21/2100Z to
22/2100Z: Solar activity has been at moderate 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 chance for M-class flares on days one, two, and three (23 May, 24 May,
25 May).

IIA.  Geophysical Activity Summary 21/2100Z to 22/2100Z: The geomagnetic
field has been at quiet levels for the past 24 hours. Solar wind speed
reached a peak of 433 km/s at 22/0022Z. Total IMF reached 7 nT at
22/0249Z. The maximum southward component of Bz reached -4 nT at
21/2234Z.  Electrons greater than 2 MeV at geosynchronous orbit reached
a peak level of 3762 pfu.
IIB.  Geophysical Activity Forecast: The geomagnetic field is expected
to be at quiet to unsettled levels on day one (23 May) and quiet levels
on days two and three (24 May, 25 May).

III.  Event probabilities 23 May-25 May
Class M    25/25/25
Class X    05/05/05
Proton     05/05/05
PCAF       green

IV.  Penticton 10.7 cm Flux
Observed           22 May 124
Predicted   23 May-25 May 125/125/130
90 Day Mean        22 May 124

V.  Geomagnetic A Indices
Observed Afr/Ap 21 May  006/007
Estimated Afr/Ap 22 May  005/006
Predicted Afr/Ap 23 May-25 May  008/008-006/005-005/005

VI.  Geomagnetic Activity Probabilities 23 May-25 May
A.  Middle Latitudes
Active                20/10/10
Minor Storm           05/05/05
Major-severe storm    01/01/01
B.  High Latitudes
Active                20/15/15
Minor Storm           30/20/20
Major-severe storm    20/20/15