:Product: 0331RSGA.txt
:Issued: 2025 Mar 31 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 90 Issued at 2200Z on 31 Mar 2025

IA.  Analysis of Solar Active Regions and Activity from 30/2100Z to
31/2100Z: Solar activity has been at moderate levels for the past 24
hours. There are currently 7 numbered sunspot regions on the disk.
IB.  Solar Activity Forecast: Solar activity is expected to be moderate
with a chance for X-class flares on days one, two, and three (01 Apr, 02
Apr, 03 Apr).

IIA.  Geophysical Activity Summary 30/2100Z to 31/2100Z: The geomagnetic
field has been at quiet to unsettled levels for the past 24 hours. Solar
wind speed reached a peak of 534 km/s at 31/1444Z. Total IMF reached 11
nT at 31/1109Z. The maximum southward component of Bz reached -7 nT at
31/1515Z.  Protons greater than 10 MeV at geosynchronous orbit reached a
peak level of 37 pfu at 31/1725Z. Electrons greater than 2 MeV at
geosynchronous orbit reached a peak level of 2038 pfu.
IIB.  Geophysical Activity Forecast: The geomagnetic field is expected
to be at quiet to unsettled levels on days one and two (01 Apr, 02 Apr)
and quiet levels on day three (03 Apr). Protons are expected to cross
threshold on day one (01 Apr), have a chance of crossing threshold on
day two (02 Apr) and have a chance of crossing threshold on day three
(03 Apr).

III.  Event probabilities 01 Apr-03 Apr
Class M    75/75/75
Class X    25/25/25
Proton     80/35/25
PCAF       yellow

IV.  Penticton 10.7 cm Flux
Observed           31 Mar 172
Predicted   01 Apr-03 Apr 175/175/170
90 Day Mean        31 Mar 179

V.  Geomagnetic A Indices
Observed Afr/Ap 30 Mar  008/010
Estimated Afr/Ap 31 Mar  008/008
Predicted Afr/Ap 01 Apr-03 Apr  009/010-008/008-006/005

VI.  Geomagnetic Activity Probabilities 01 Apr-03 Apr
A.  Middle Latitudes
Active                20/20/10
Minor Storm           05/05/01
Major-severe storm    01/01/01
B.  High Latitudes
Active                15/15/15
Minor Storm           30/30/20
Major-severe storm    25/25/20
