:Product: 0521RSGA.txt
:Issued: 2024 May 21 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 21 May 2024

IA.  Analysis of Solar Active Regions and Activity from 20/2100Z to
21/2100Z: 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
21/1931Z from Region 3679 (S09W46). There are currently 9 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
(22 May, 23 May, 24 May).

IIA.  Geophysical Activity Summary 20/2100Z to 21/2100Z: The geomagnetic
field has been at quiet to unsettled levels for the past 24 hours. Solar
wind speed reached a peak of 467 km/s at 21/1847Z. Total IMF reached 7
nT at 21/1836Z. The maximum southward component of Bz reached -6 nT at
21/1355Z.  Electrons greater than 2 MeV at geosynchronous orbit reached
a peak level of 764 pfu.
IIB.  Geophysical Activity Forecast: The geomagnetic field is expected
to be at quiet to unsettled levels on days one and two (22 May, 23 May)
and unsettled to active levels on day three (24 May). Protons have a
slight chance of crossing threshold on days one, two, and three (22 May,
23 May, 24 May).

III.  Event probabilities 22 May-24 May
Class M    55/55/55
Class X    10/10/10
Proton     10/10/10
PCAF       green

IV.  Penticton 10.7 cm Flux
Observed           21 May 191
Predicted   22 May-24 May 190/192/192
90 Day Mean        21 May 169

V.  Geomagnetic A Indices
Observed Afr/Ap 20 May  010/008
Estimated Afr/Ap 21 May  009/010
Predicted Afr/Ap 22 May-24 May  007/008-008/008-011/014

VI.  Geomagnetic Activity Probabilities 22 May-24 May
A.  Middle Latitudes
Active                25/15/30
Minor Storm           05/05/10
Major-severe storm    01/01/01
B.  High Latitudes
Active                20/15/15
Minor Storm           30/25/25
Major-severe storm    30/25/40