:Product: 0417RSGA.txt
:Issued: 2023 Apr 17 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 107 Issued at 2200Z on 17 Apr 2023

IA.  Analysis of Solar Active Regions and Activity from 16/2100Z to
17/2100Z: 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
17/0633Z from Region 3281 (S22E14). There are currently 9 numbered
sunspot regions on the disk.
IB.  Solar Activity Forecast: Solar activity is expected to be low with
a chance for M-class flares and a slight chance for an X-class flare on
days one, two, and three (18 Apr, 19 Apr, 20 Apr).

IIA.  Geophysical Activity Summary 16/2100Z to 17/2100Z: The geomagnetic
field has been at quiet levels for the past 24 hours. Solar wind speed
reached a peak of 532 km/s at 17/1637Z. Total IMF reached 9 nT at
17/1144Z. The maximum southward component of Bz reached -8 nT at
17/1144Z.  Electrons greater than 2 MeV at geosynchronous orbit reached
a peak level of 141 pfu.
IIB.  Geophysical Activity Forecast: The geomagnetic field is expected
to be at quiet levels on days one, two, and three (18 Apr, 19 Apr, 20
Apr).

III.  Event probabilities 18 Apr-20 Apr
Class M    45/45/45
Class X    10/10/10
Proton     05/05/05
PCAF       green

IV.  Penticton 10.7 cm Flux
Observed           17 Apr 167
Predicted   18 Apr-20 Apr 170/168/168
90 Day Mean        17 Apr 163

V.  Geomagnetic A Indices
Observed Afr/Ap 16 Apr  004/005
Estimated Afr/Ap 17 Apr  005/005
Predicted Afr/Ap 18 Apr-20 Apr  006/005-005/005-005/005

VI.  Geomagnetic Activity Probabilities 18 Apr-20 Apr
A.  Middle Latitudes
Active                10/10/10
Minor Storm           05/05/05
Major-severe storm    01/01/01
B.  High Latitudes
Active                15/15/15
Minor Storm           20/20/20
Major-severe storm    15/15/15