:Product: 0531RSGA.txt
:Issued: 2025 May 31 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 151 Issued at 2200Z on 31 May 2025

IA.  Analysis of Solar Active Regions and Activity from 30/2100Z to
31/2100Z: Solar activity has been at high levels for the past 24 hours.
There are currently 5 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 (01 Jun, 02
Jun, 03 Jun).

IIA.  Geophysical Activity Summary 30/2100Z to 31/2100Z: The geomagnetic
field has been at quiet to active levels for the past 24 hours. Solar
wind speed reached a peak of 822 km/s at 31/0518Z. Total IMF reached 7
nT at 31/0045Z. The maximum southward component of Bz reached -6 nT at
30/2248Z.  Protons greater than 10 MeV at geosynchronous orbit reached a
peak level of 25 pfu at 31/2045Z. Electrons greater than 2 MeV at
geosynchronous orbit reached a peak level of 9162 pfu.
IIB.  Geophysical Activity Forecast: The geomagnetic field is expected
to be at active to severe storm levels on day one (01 Jun), minor storm
to severe storm levels on day two (02 Jun) and active to major storm
levels on day three (03 Jun). Protons are expected to cross threshold on
days one, two, and three (01 Jun, 02 Jun, 03 Jun).

III.  Event probabilities 01 Jun-03 Jun
Class M    65/65/65
Class X    25/25/25
Proton     75/75/75
PCAF       yellow

IV.  Penticton 10.7 cm Flux
Observed           31 May 164
Predicted   01 Jun-03 Jun 165/160/150
90 Day Mean        31 May 154

V.  Geomagnetic A Indices
Observed Afr/Ap 30 May  018/016
Estimated Afr/Ap 31 May  014/018
Predicted Afr/Ap 01 Jun-03 Jun  052/096-055/100-031/044

VI.  Geomagnetic Activity Probabilities 01 Jun-03 Jun
A.  Middle Latitudes
Active                05/15/30
Minor Storm           40/35/35
Major-severe storm    55/55/25
B.  High Latitudes
Active                01/01/05
Minor Storm           05/05/15
Major-severe storm    95/95/80
