:Product: 0527RSGA.txt
:Issued: 2023 May 27 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 147 Issued at 2200Z on 27 May 2023

IA.  Analysis of Solar Active Regions and Activity from 26/2100Z to
27/2100Z: Solar activity has been at low levels for the past 24 hours.
The largest solar event of the period was a C8 event observed at
27/0435Z from Region 3314 (N15W58). 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
(28 May, 29 May, 30 May).

IIA.  Geophysical Activity Summary 26/2100Z to 27/2100Z: The geomagnetic
field has been at quiet levels for the past 24 hours. Solar wind speed
reached a peak of 535 km/s at 27/0250Z. Total IMF reached 5 nT at
27/0553Z. The maximum southward component of Bz reached -4 nT at
27/0745Z.  Electrons greater than 2 MeV at geosynchronous orbit reached
a peak level of 4253 pfu.
IIB.  Geophysical Activity Forecast: The geomagnetic field is expected
to be at quiet levels on day one (28 May), quiet to active levels on day
two (29 May) and quiet to unsettled levels on day three (30 May).
Protons have a slight chance of crossing threshold on days one, two, and
three (28 May, 29 May, 30 May).

III.  Event probabilities 28 May-30 May
Class M    55/55/55
Class X    10/10/10
Proton     10/10/10
PCAF       green

IV.  Penticton 10.7 cm Flux
Observed           27 May 157
Predicted   28 May-30 May 155/155/145
90 Day Mean        27 May 153

V.  Geomagnetic A Indices
Observed Afr/Ap 26 May  006/006
Estimated Afr/Ap 27 May  003/004
Predicted Afr/Ap 28 May-30 May  005/005-009/012-010/010

VI.  Geomagnetic Activity Probabilities 28 May-30 May
A.  Middle Latitudes
Active                10/30/20
Minor Storm           05/15/05
Major-severe storm    01/01/01
B.  High Latitudes
Active                15/15/15
Minor Storm           20/20/25
Major-severe storm    15/30/25