:Product: 1219RSGA.txt
:Issued: 2023 Dec 19 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 353 Issued at 2200Z on 19 Dec 2023

IA.  Analysis of Solar Active Regions and Activity from 18/2100Z to
19/2100Z: Solar activity has been at low levels for the past 24 hours.
The largest solar event of the period was a C7 event observed at
19/0304Z from Region 3528 (N08E01). There are currently 10 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 (20 Dec, 21 Dec,
22 Dec).

IIA.  Geophysical Activity Summary 18/2100Z to 19/2100Z: The geomagnetic
field has been at quiet to minor storm levels for the past 24 hours.
Solar wind speed reached a peak of 835 km/s at 19/0311Z. Total IMF
reached 10 nT at 18/2126Z. The maximum southward component of Bz reached
-9 nT at 18/2100Z.  Electrons greater than 2 MeV at geosynchronous orbit
reached a peak level of 208 pfu.
IIB.  Geophysical Activity Forecast: The geomagnetic field is expected
to be at quiet to active levels on day one (20 Dec), quiet to unsettled
levels on day two (21 Dec) and quiet levels on day three (22 Dec).

III.  Event probabilities 20 Dec-22 Dec
Class M    25/25/25
Class X    05/05/05
Proton     01/01/01
PCAF       green

IV.  Penticton 10.7 cm Flux
Observed           19 Dec 179
Predicted   20 Dec-22 Dec 180/178/178
90 Day Mean        19 Dec 149

V.  Geomagnetic A Indices
Observed Afr/Ap 18 Dec  016/020
Estimated Afr/Ap 19 Dec  012/016
Predicted Afr/Ap 20 Dec-22 Dec  010/012-007/010-005/005

VI.  Geomagnetic Activity Probabilities 20 Dec-22 Dec
A.  Middle Latitudes
Active                25/15/10
Minor Storm           10/05/01
Major-severe storm    01/01/01
B.  High Latitudes
Active                15/15/15
Minor Storm           20/15/15
Major-severe storm    20/10/10