:Product: 0421RSGA.txt
:Issued: 2023 Apr 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 111 Issued at 2200Z on 21 Apr 2023

IA.  Analysis of Solar Active Regions and Activity from 20/2100Z to
21/2100Z: Solar activity has been at low levels for the past 24 hours.
The largest solar event of the period was a C2 event observed at
20/2230Z from Region 3281 (S22W22). There are currently 7 numbered
sunspot regions on the disk.
IB.  Solar Activity Forecast: Solar activity is expected to be low with
a chance for M-class flares on days one, two, and three (22 Apr, 23 Apr,
24 Apr).

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 514 km/s at 21/2036Z. Total IMF reached 6
nT at 21/1836Z. The maximum southward component of Bz reached -6 nT at
21/1815Z.  Electrons greater than 2 MeV at geosynchronous orbit reached
a peak level of 131 pfu.
IIB.  Geophysical Activity Forecast: The geomagnetic field is expected
to be at quiet to active levels on days one and two (22 Apr, 23 Apr) and
quiet to unsettled levels on day three (24 Apr).

III.  Event probabilities 22 Apr-24 Apr
Class M    40/40/40
Class X    01/01/01
Proton     05/05/05
PCAF       green

IV.  Penticton 10.7 cm Flux
Observed           21 Apr 151
Predicted   22 Apr-24 Apr 140/135/130
90 Day Mean        21 Apr 160

V.  Geomagnetic A Indices
Observed Afr/Ap 20 Apr  005/004
Estimated Afr/Ap 21 Apr  009/010
Predicted Afr/Ap 22 Apr-24 Apr  014/016-010/012-008/008

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