:Product: 1221RSGA.txt
:Issued: 2015 Dec 21 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 355 Issued at 2200Z on 21 Dec 2015

IA.  Analysis of Solar Active Regions and Activity from 20/2100Z to
21/2100Z: Solar activity has been at moderate levels for the past 24
hours. The largest solar event of the period was a M2 event observed at
21/0103Z from Region 2472 (N04E78). There are currently 3 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 (22 Dec, 23 Dec,
24 Dec).

IIA.  Geophysical Activity Summary 20/2100Z to 21/2100Z: The geomagnetic
field has been at quiet to major storm levels for the past 24 hours.
Solar wind speed, as measured by the ACE spacecraft, reached a peak
speed of 452 km/s at 21/0036Z. Total IMF reached 19 nT at 20/2231Z. The
maximum southward component of Bz reached -18 nT at 20/2210Z. Electrons
greater than 2 MeV at geosynchronous orbit reached a peak level of 1545
pfu.
IIB.  Geophysical Activity Forecast: The geomagnetic field is expected
to be at quiet to active levels on day one (22 Dec) and quiet levels on
days two and three (23 Dec, 24 Dec).

III.  Event probabilities 22 Dec-24 Dec
Class M    25/25/25
Class X    05/05/05
Proton     01/01/01
PCAF       green

IV.  Penticton 10.7 cm Flux
Observed           21 Dec 122
Predicted   22 Dec-24 Dec 125/130/130
90 Day Mean        21 Dec 109

V.  Geomagnetic A Indices
Observed Afr/Ap 20 Dec  033/068
Estimated Afr/Ap 21 Dec  025/040
Predicted Afr/Ap 22 Dec-24 Dec  011/010-006/006-006/005

VI.  Geomagnetic Activity Probabilities 22 Dec-24 Dec
A.  Middle Latitudes
Active                15/10/10
Minor Storm           05/01/05
Major-severe storm    01/01/01
B.  High Latitudes
Active                20/15/15
Minor Storm           30/25/25
Major-severe storm    20/10/20