:Product: 1217RSGA.txt
:Issued: 2021 Dec 17 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 351 Issued at 2200Z on 17 Dec 2021

IA.  Analysis of Solar Active Regions and Activity from 16/2100Z to
17/2100Z: 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
17/0051Z from Region 2911 (N19E54). 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 (18 Dec, 19 Dec,
20 Dec).

IIA.  Geophysical Activity Summary 16/2100Z to 17/2100Z: The geomagnetic
field has been at quiet levels for the past 24 hours. Solar wind speed
reached a peak of 477 km/s at 16/2152Z.  Electrons greater than 2 MeV at
geosynchronous orbit reached a peak level of 159 pfu.
IIB.  Geophysical Activity Forecast: The geomagnetic field is expected
to be at quiet to unsettled levels on days one, two, and three (18 Dec,
19 Dec, 20 Dec).

III.  Event probabilities 18 Dec-20 Dec
Class M    25/25/25
Class X    05/05/05
Proton     05/05/05
PCAF       green

IV.  Penticton 10.7 cm Flux
Observed           17 Dec 121
Predicted   18 Dec-20 Dec 121/121/122
90 Day Mean        17 Dec 088

V.  Geomagnetic A Indices
Observed Afr/Ap 16 Dec  005/005
Estimated Afr/Ap 17 Dec  006/007
Predicted Afr/Ap 18 Dec-20 Dec  007/008-006/008-009/010

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