:Product: 1216RSGA.txt
:Issued: 2023 Dec 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 350 Issued at 2200Z on 16 Dec 2023

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.
The largest solar event of the period was a C8 event observed at
16/1354Z from Region 3514 (N05W82). There are currently 11 numbered
sunspot regions on the disk.
IB.  Solar Activity Forecast: Solar activity is likely to be moderate
with a chance for X-class flares on day one (17 Dec) and expected to be
low with a chance for M-class flares on days two and three (18 Dec, 19
Dec).

IIA.  Geophysical Activity Summary 15/2100Z to 16/2100Z: The geomagnetic
field has been at quiet to active levels for the past 24 hours. Solar
wind speed reached a peak of 524 km/s at 16/0036Z. Total IMF reached 12
nT at 15/2100Z. The maximum southward component of Bz reached -7 nT at
16/1913Z.  Protons greater than 10 MeV at geosynchronous orbit reached a
peak level of 13 pfu at 16/0015Z. Electrons greater than 2 MeV at
geosynchronous orbit reached a peak level of 197 pfu.
IIB.  Geophysical Activity Forecast: The geomagnetic field is expected
to be at unsettled to major storm levels on day one (17 Dec), quiet to
minor storm levels on day two (18 Dec) and quiet to active levels on day
three (19 Dec). Protons greater than 10 Mev have a chance of crossing
threshold on day one (17 Dec).

III.  Event probabilities 17 Dec-19 Dec
Class M    55/25/25
Class X    25/05/05
Proton     30/05/05
PCAF       green

IV.  Penticton 10.7 cm Flux
Observed           16 Dec 149
Predicted   17 Dec-19 Dec 145/140/138
90 Day Mean        16 Dec 149

V.  Geomagnetic A Indices
Observed Afr/Ap 15 Dec  008/011
Estimated Afr/Ap 16 Dec  016/019
Predicted Afr/Ap 17 Dec-19 Dec  025/032-014/018-009/012

VI.  Geomagnetic Activity Probabilities 17 Dec-19 Dec
A.  Middle Latitudes
Active                30/30/25
Minor Storm           30/15/05
Major-severe storm    20/01/01
B.  High Latitudes
Active                15/20/15
Minor Storm           20/20/20
Major-severe storm    20/10/20