:Product: 0417RSGA.txt
:Issued: 2025 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 2025

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.
There are currently 7 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
(18 Apr, 19 Apr, 20 Apr).

IIA.  Geophysical Activity Summary 16/2100Z to 17/2100Z: The geomagnetic
field has been at quiet to minor storm levels for the past 24 hours.
Solar wind speed reached a peak of 652 km/s at 16/2111Z. Total IMF
reached 17 nT at 17/0728Z. The maximum southward component of Bz reached
-4 nT at 17/0939Z.  Electrons greater than 2 MeV at geosynchronous orbit
reached a peak level of 305 pfu.
IIB.  Geophysical Activity Forecast: The geomagnetic field is expected
to be at quiet to active levels on day one (18 Apr) and quiet to
unsettled levels on days two and three (19 Apr, 20 Apr).

III.  Event probabilities 18 Apr-20 Apr
Class M    55/55/55
Class X    10/10/10
Proton     01/01/01
PCAF       green

IV.  Penticton 10.7 cm Flux
Observed           17 Apr 151
Predicted   18 Apr-20 Apr 150/148/148
90 Day Mean        17 Apr 176

V.  Geomagnetic A Indices
Observed Afr/Ap 16 Apr  043/077
Estimated Afr/Ap 17 Apr  010/011
Predicted Afr/Ap 18 Apr-20 Apr  011/012-008/010-008/008

VI.  Geomagnetic Activity Probabilities 18 Apr-20 Apr
A.  Middle Latitudes
Active                25/15/15
Minor Storm           10/05/05
Major-severe storm    01/01/01
B.  High Latitudes
Active                15/15/15
Minor Storm           25/25/20
Major-severe storm    35/25/20