:Product: 1231RSGA.txt
:Issued: 2023 Dec 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 365 Issued at 2200Z on 31 Dec 2023

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. The largest solar event of the period was a M1 event observed at
31/1912Z from Region 3536 (N05E75). There are currently 4 numbered
sunspot regions on the disk.
IB.  Solar Activity Forecast: Solar activity is expected to be low with
a chance for M-class flares on days one, two, and three (01 Jan, 02 Jan,
03 Jan).

IIA.  Geophysical Activity Summary 30/2100Z to 31/2100Z: The geomagnetic
field has been at quiet levels for the past 24 hours. Solar wind speed
reached a peak of 481 km/s at 31/0123Z. Total IMF reached 8 nT at
31/0538Z. The maximum southward component of Bz reached -5 nT at
31/1714Z.  Electrons greater than 2 MeV at geosynchronous orbit reached
a peak level of 199 pfu.
IIB.  Geophysical Activity Forecast: The geomagnetic field is expected
to be at quiet to active levels on days one and two (01 Jan, 02 Jan) and
quiet levels on day three (03 Jan).

III.  Event probabilities 01 Jan-03 Jan
Class M    30/30/30
Class X    01/01/01
Proton     01/01/01
PCAF       green

IV.  Penticton 10.7 cm Flux
Observed           31 Dec 146
Predicted   01 Jan-03 Jan 145/140/140
90 Day Mean        31 Dec 149

V.  Geomagnetic A Indices
Observed Afr/Ap 30 Dec  004/003
Estimated Afr/Ap 31 Dec  003/004
Predicted Afr/Ap 01 Jan-03 Jan  011/015-012/012-007/008

VI.  Geomagnetic Activity Probabilities 01 Jan-03 Jan
A.  Middle Latitudes
Active                30/20/20
Minor Storm           15/05/05
Major-severe storm    01/01/01
B.  High Latitudes
Active                15/15/15
Minor Storm           30/25/25
Major-severe storm    40/30/25