:Product: 0420RSGA.txt
:Issued: 2024 Apr 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 111 Issued at 2200Z on 20 Apr 2024

IA.  Analysis of Solar Active Regions and Activity from 19/2100Z to
20/2100Z: Solar activity has been at low levels for the past 24 hours.
The largest solar event of the period was a C7 event observed at
20/1706Z from Region 3645 (S09W20). There are currently 14 numbered
sunspot regions on the disk.
IB.  Solar Activity Forecast: Solar activity is expected to be moderate
with a slight chance for an X-class flare on days one, two, and three
(21 Apr, 22 Apr, 23 Apr).

IIA.  Geophysical Activity Summary 19/2100Z to 20/2100Z: The geomagnetic
field has been at quiet to active levels for the past 24 hours. Solar
wind speed reached a peak of 532 km/s at 20/0553Z. Total IMF reached 10
nT at 19/2100Z. The maximum southward component of Bz reached -8 nT at
19/2120Z.  Electrons greater than 2 MeV at geosynchronous orbit reached
a peak level of 118 pfu.
IIB.  Geophysical Activity Forecast: The geomagnetic field is expected
to be at quiet to active levels on days one and three (21 Apr, 23 Apr)
and quiet to unsettled levels on day two (22 Apr). Protons have a slight
chance of crossing threshold on days one, two, and three (21 Apr, 22
Apr, 23 Apr).

III.  Event probabilities 21 Apr-23 Apr
Class M    75/75/75
Class X    20/20/20
Proton     20/20/20
PCAF       green

IV.  Penticton 10.7 cm Flux
Observed           20 Apr 210
Predicted   21 Apr-23 Apr 210/205/200
90 Day Mean        20 Apr 161

V.  Geomagnetic A Indices
Observed Afr/Ap 19 Apr  021/046
Estimated Afr/Ap 20 Apr  007/009
Predicted Afr/Ap 21 Apr-23 Apr  011/012-008/008-011/015

VI.  Geomagnetic Activity Probabilities 21 Apr-23 Apr
A.  Middle Latitudes
Active                35/20/35
Minor Storm           15/05/20
Major-severe storm    01/01/05
B.  High Latitudes
Active                15/15/10
Minor Storm           30/25/25
Major-severe storm    50/25/50