:Product: 1218RSGA.txt
:Issued: 2021 Dec 18 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 352 Issued at 2200Z on 18 Dec 2021

IA.  Analysis of Solar Active Regions and Activity from 17/2100Z to
18/2100Z: Solar activity has been at low levels for the past 24 hours.
The largest solar event of the period was a C6 event observed at
18/1801Z. There are currently 6 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 (19 Dec, 20 Dec,
21 Dec).

IIA.  Geophysical Activity Summary 17/2100Z to 18/2100Z: The geomagnetic
field has been at quiet levels for the past 24 hours. Solar wind speed
reached a peak of 379 km/s at 17/2115Z.  Electrons greater than 2 MeV at
geosynchronous orbit reached a peak level of 189 pfu.
IIB.  Geophysical Activity Forecast: The geomagnetic field is expected
to be at quiet to unsettled levels on days one and two (19 Dec, 20 Dec)
and quiet to active levels on day three (21 Dec).

III.  Event probabilities 19 Dec-21 Dec
Class M    25/25/25
Class X    05/05/05
Proton     05/05/05
PCAF       green

IV.  Penticton 10.7 cm Flux
Observed           18 Dec 121
Predicted   19 Dec-21 Dec 122/123/125
90 Day Mean        18 Dec 088

V.  Geomagnetic A Indices
Observed Afr/Ap 17 Dec  002/001
Estimated Afr/Ap 18 Dec  004/005
Predicted Afr/Ap 19 Dec-21 Dec  006/008-009/010-013/016

VI.  Geomagnetic Activity Probabilities 19 Dec-21 Dec
A.  Middle Latitudes
Active                10/20/30
Minor Storm           01/05/15
Major-severe storm    01/01/01
B.  High Latitudes
Active                15/15/15
Minor Storm           20/25/30
Major-severe storm    20/25/45