:Product: 1215RSGA.txt
:Issued: 2023 Dec 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 349 Issued at 2200Z on 15 Dec 2023

IA.  Analysis of Solar Active Regions and Activity from 14/2100Z to
15/2100Z: Solar activity has been at high levels for the past 24 hours.
The largest solar event of the period was a M6 event observed at
15/0734Z from Region 3514 (N05W68). There are currently 8 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 days one, two, and three (16 Dec, 17
Dec, 18 Dec).

IIA.  Geophysical Activity Summary 14/2100Z to 15/2100Z: The geomagnetic
field has been at quiet to unsettled levels for the past 24 hours. Solar
wind speed reached a peak of 510 km/s at 15/1545Z. Total IMF reached 23
nT at 15/1443Z. The maximum southward component of Bz reached -12 nT at
15/1110Z.  Protons greater than 10 MeV at geosynchronous orbit reached a
peak level of 6 pfu at 15/1650Z. Electrons greater than 2 MeV at
geosynchronous orbit reached a peak level of 367 pfu.
IIB.  Geophysical Activity Forecast: The geomagnetic field is expected
to be at quiet to major storm levels on day one (16 Dec), unsettled to
major storm levels on day two (17 Dec) and quiet to active levels on day
three (18 Dec). Protons have a chance of crossing threshold on day one
(16 Dec), have a chance of crossing threshold on day two (17 Dec) and
have a slight chance of crossing threshold on day three (18 Dec).

III.  Event probabilities 16 Dec-18 Dec
Class M    55/55/55
Class X    25/25/25
Proton     50/35/10
PCAF       green

IV.  Penticton 10.7 cm Flux
Observed           15 Dec 144
Predicted   16 Dec-18 Dec 145/145/140
90 Day Mean        15 Dec 149

V.  Geomagnetic A Indices
Observed Afr/Ap 14 Dec  013/013
Estimated Afr/Ap 15 Dec  011/012
Predicted Afr/Ap 16 Dec-18 Dec  017/024-025/032-013/018

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