:Product: 0526RSGA.txt
:Issued: 2025 May 26 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 146 Issued at 2200Z on 26 May 2025

IA.  Analysis of Solar Active Regions and Activity from 25/2100Z to
26/2100Z: Solar activity has been at moderate levels for the past 24
hours. There are currently 8 numbered sunspot regions on the disk.
IB.  Solar Activity Forecast: Solar activity is likely to be moderate
with a chance for X-class flares on days one, two, and three (27 May, 28
May, 29 May).

IIA.  Geophysical Activity Summary 25/2100Z to 26/2100Z: The geomagnetic
field has been at quiet to unsettled levels for the past 24 hours. Solar
wind speed reached a peak of 495 km/s at 26/0639Z. Total IMF reached 10
nT at 26/0520Z. The maximum southward component of Bz reached -9 nT at
26/0531Z.  Electrons greater than 2 MeV at geosynchronous orbit reached
a peak level of 1021 pfu.
IIB.  Geophysical Activity Forecast: The geomagnetic field is expected
to be at quiet to unsettled levels on day one (27 May), quiet to minor
storm levels on day two (28 May) and quiet to active levels on day three
(29 May). Protons have a slight chance of crossing threshold on days
one, two, and three (27 May, 28 May, 29 May).

III.  Event probabilities 27 May-29 May
Class M    70/70/70
Class X    30/30/30
Proton     15/15/15
PCAF       green

IV.  Penticton 10.7 cm Flux
Observed           26 May 133
Predicted   27 May-29 May 135/130/125
90 Day Mean        26 May 155

V.  Geomagnetic A Indices
Observed Afr/Ap 25 May  008/ 006
Estimated Afr/Ap 26 May  008/008
Predicted Afr/Ap 27 May-29 May  008/008-016/025-015/016

VI.  Geomagnetic Activity Probabilities 27 May-29 May
A.  Middle Latitudes
Active                20/40/35
Minor Storm           05/25/15
Major-severe storm    01/05/01
B.  High Latitudes
Active                15/10/10
Minor Storm           25/25/30
Major-severe storm    25/60/50
