:Product: Report of Solar-Geophysical Activity
:Issued: 2024 Apr 24 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 115 Issued at 2200Z on 24 Apr 2024

IA.  Analysis of Solar Active Regions and Activity from 23/2100Z to
24/2100Z: 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
24/0239Z from Region 3638 (S17W74). There are currently 16 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
(25 Apr, 26 Apr, 27 Apr).

IIA.  Geophysical Activity Summary 23/2100Z to 24/2100Z: The geomagnetic
field has been at quiet levels for the past 24 hours. Solar wind speed
reached a peak of 422 km/s at 24/0808Z. Total IMF reached 5 nT at
23/2114Z. The maximum southward component of Bz reached -5 nT at
23/2114Z.  Electrons greater than 2 MeV at geosynchronous orbit reached
a peak level of 1006 pfu.
IIB.  Geophysical Activity Forecast: The geomagnetic field is expected
to be at unsettled to active levels on day one (25 Apr) and quiet to
active levels on days two and three (26 Apr, 27 Apr). Protons have a
slight chance of crossing threshold on days one, two, and three (25 Apr,
26 Apr, 27 Apr).

III.  Event probabilities 25 Apr-27 Apr
Class M    75/75/75
Class X    15/15/15
Proton     15/15/15
PCAF       green

IV.  Penticton 10.7 cm Flux
Observed           24 Apr 199
Predicted   25 Apr-27 Apr 195/185/170
90 Day Mean        24 Apr 163

V.  Geomagnetic A Indices
Observed Afr/Ap 23 Apr  009/007
Estimated Afr/Ap 24 Apr  004/004
Predicted Afr/Ap 25 Apr-27 Apr  016/020-015/018-011/015

VI.  Geomagnetic Activity Probabilities 25 Apr-27 Apr
A.  Middle Latitudes
Active                35/35/35
Minor Storm           25/20/20
Major-severe storm    05/05/05
B.  High Latitudes
Active                10/10/10
Minor Storm           25/30/30
Major-severe storm    60/55/55