:Product: 0416RSGA.txt
:Issued: 2025 Apr 16 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 106 Issued at 2200Z on 16 Apr 2025

IA.  Analysis of Solar Active Regions and Activity from 15/2100Z to
16/2100Z: Solar activity has been at low levels for the past 24 hours.
There are currently 5 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, two, and three
(17 Apr, 18 Apr, 19 Apr).

IIA.  Geophysical Activity Summary 15/2100Z to 16/2100Z: The geomagnetic
field has been at unsettled to severe storm levels for the past 24
hours. Solar wind speed reached a peak of 663 km/s at 16/0138Z. Total
IMF reached 24 nT at 16/0032Z. The maximum southward component of Bz
reached -17 nT at 15/2101Z.  Electrons greater than 2 MeV at
geosynchronous orbit reached a peak level of 885 pfu.
IIB.  Geophysical Activity Forecast: The geomagnetic field is expected
to be at unsettled to minor storm levels on day one (17 Apr), unsettled
to active levels on day two (18 Apr) and quiet to unsettled levels on
day three (19 Apr).

III.  Event probabilities 17 Apr-19 Apr
Class M    60/60/60
Class X    10/10/10
Proton     01/01/01
PCAF       green

IV.  Penticton 10.7 cm Flux
Observed           16 Apr 148
Predicted   17 Apr-19 Apr 155/150/150
90 Day Mean        16 Apr 177

V.  Geomagnetic A Indices
Observed Afr/Ap 15 Apr  013/ NA
Estimated Afr/Ap 16 Apr  026/041
Predicted Afr/Ap 17 Apr-19 Apr  022/030-014/018-008/010

VI.  Geomagnetic Activity Probabilities 17 Apr-19 Apr
A.  Middle Latitudes
Active                35/25/15
Minor Storm           25/10/05
Major-severe storm    15/01/01
B.  High Latitudes
Active                10/15/15
Minor Storm           25/25/25
Major-severe storm    65/35/25
