:Product: 0415RSGA.txt
:Issued: 2025 Apr 15 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 105 Issued at 2200Z on 15 Apr 2025

IA.  Analysis of Solar Active Regions and Activity from 14/2100Z to
15/2100Z: Solar activity has been at moderate levels for the past 24
hours. There are currently 4 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 and two (16 Apr,
17 Apr) and likely to be moderate with a slight chance for an X-class
flare on day three (18 Apr).

IIA.  Geophysical Activity Summary 14/2100Z to 15/2100Z: The geomagnetic
field has been at quiet to major storm levels for the past 24 hours.
Solar wind speed reached a peak of 617 km/s at 15/2040Z. Total IMF
reached 27 nT at 15/1822Z. The maximum southward component of Bz reached
-20 nT at 15/1820Z.  Electrons greater than 2 MeV at geosynchronous
orbit reached a peak level of 2379 pfu.
IIB.  Geophysical Activity Forecast: The geomagnetic field is expected
to be at active to severe storm levels on day one (16 Apr), unsettled to
minor storm levels on day two (17 Apr) and unsettled to active levels on
day three (18 Apr). Protons greater than 10 Mev have a slight chance of
crossing threshold on days one and two (16 Apr, 17 Apr).

III.  Event probabilities 16 Apr-18 Apr
Class M    80/75/60
Class X    15/10/10
Proton     10/10/05
PCAF       green

IV.  Penticton 10.7 cm Flux
Observed           15 Apr 153
Predicted   16 Apr-18 Apr 160/160/155
90 Day Mean        15 Apr 178

V.  Geomagnetic A Indices
Observed Afr/Ap 14 Apr  014/ NA
Estimated Afr/Ap 15 Apr  012/015
Predicted Afr/Ap 16 Apr-18 Apr  030/054-022/030-014/018

VI.  Geomagnetic Activity Probabilities 16 Apr-18 Apr
A.  Middle Latitudes
Active                30/35/25
Minor Storm           40/25/10
Major-severe storm    20/15/01
B.  High Latitudes
Active                05/10/15
Minor Storm           15/25/25
Major-severe storm    75/65/35
