:Product: 0528RSGA.txt
:Issued: 2023 May 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 148 Issued at 2200Z on 28 May 2023

IA.  Analysis of Solar Active Regions and Activity from 27/2100Z to
28/2100Z: Solar activity has been at moderate levels for the past 24
hours. The largest solar event of the period was a M1 event observed at
28/1036Z from Region 3315 (S17W22). There are currently 7 numbered
sunspot regions on the disk.
IB.  Solar Activity Forecast: Solar activity is likely to be moderate
with a slight chance for an X-class flare on days one, two, and three
(29 May, 30 May, 31 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 517 km/s at 27/2306Z. Total IMF reached 5
nT at 28/1725Z. The maximum southward component of Bz reached -5 nT at
28/0624Z.  Electrons greater than 2 MeV at geosynchronous orbit reached
a peak level of 2691 pfu.
IIB.  Geophysical Activity Forecast: The geomagnetic field is expected
to be at quiet to active levels on day one (29 May), quiet to unsettled
levels on day two (30 May) and quiet levels on day three (31 May).
Protons have a slight chance of crossing threshold on days one, two, and
three (29 May, 30 May, 31 May).

III.  Event probabilities 29 May-31 May
Class M    55/55/55
Class X    10/10/10
Proton     10/10/10
PCAF       green

IV.  Penticton 10.7 cm Flux
Observed           28 May 151
Predicted   29 May-31 May 150/145/140
90 Day Mean        28 May 153

V.  Geomagnetic A Indices
Observed Afr/Ap 27 May  005/006
Estimated Afr/Ap 28 May  010/011
Predicted Afr/Ap 29 May-31 May  009/012-010/010-006/005

VI.  Geomagnetic Activity Probabilities 29 May-31 May
A.  Middle Latitudes
Active                30/20/10
Minor Storm           15/05/05
Major-severe storm    01/01/01
B.  High Latitudes
Active                15/15/15
Minor Storm           20/25/20
Major-severe storm    30/25/15