:Product: 0520RSGA.txt
:Issued: 2024 May 20 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 141 Issued at 2200Z on 20 May 2024

IA.  Analysis of Solar Active Regions and Activity from 19/2100Z to
20/2100Z: 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
19/2159Z from Region 3685 (S13E29). There are currently 6 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 and two (21 May,
22 May) and expected to be low with a chance for M-class flares and a
slight chance for an X-class flare on day three (23 May).

IIA.  Geophysical Activity Summary 19/2100Z to 20/2100Z: The geomagnetic
field has been at quiet to unsettled levels for the past 24 hours. Solar
wind speed reached a peak of 427 km/s at 20/0308Z. Total IMF reached 9
nT at 20/0041Z. The maximum southward component of Bz reached -6 nT at
20/0228Z.  Electrons greater than 2 MeV at geosynchronous orbit reached
a peak level of 512 pfu.
IIB.  Geophysical Activity Forecast: The geomagnetic field is expected
to be at unsettled to active levels on day one (21 May) and quiet levels
on days two and three (22 May, 23 May). Protons have a slight chance of
crossing threshold on days one, two, and three (21 May, 22 May, 23 May).

III.  Event probabilities 21 May-23 May
Class M    55/55/50
Class X    10/10/10
Proton     10/10/10
PCAF       green

IV.  Penticton 10.7 cm Flux
Observed           20 May 200
Predicted   21 May-23 May 200/200/200
90 Day Mean        20 May 168

V.  Geomagnetic A Indices
Observed Afr/Ap 19 May  010/009
Estimated Afr/Ap 20 May  015/021
Predicted Afr/Ap 21 May-23 May  014/016-006/005-005/005

VI.  Geomagnetic Activity Probabilities 21 May-23 May
A.  Middle Latitudes
Active                30/15/10
Minor Storm           10/05/05
Major-severe storm    01/01/01
B.  High Latitudes
Active                15/15/15
Minor Storm           25/20/15
Major-severe storm    40/20/15