Joint USAF/NOAA Solar Geophysical Activity Report and Forecast 22 December 2013

Joint USAF/NOAA Solar Geophysical Activity Report and Forecast
SDF Number 356 Issued at 2200Z on 22 Dec 2013

IA. Analysis of Solar Active Regions and Activity from 21/2100Z to
22/2100Z: Solar activity has been at moderate levels for the past 24
hours. The largest solar event of the period was a M3 event observed at
22/1512Z from Region 1928 (S17W61). There are currently 7 numbered
sunspot regions on the disk.

IB. Solar Activity Forecast: Solar activity is likely to be moderate
with a slight chance for an X-class flare on days one, two, and three
(23 Dec, 24 Dec, 25 Dec).

IIA. Geophysical Activity Summary 21/2100Z to 22/2100Z: The geomagnetic
field has been at quiet levels for the past 24 hours. Solar wind speed,
as measured by the ACE spacecraft, reached a peak speed of 354 km/s at
22/0022Z.

IIB. Geophysical Activity Forecast: The geomagnetic field is expected
to be at quiet levels on days one and two (23 Dec, 24 Dec) and quiet to
active levels on day three (25 Dec). Protons have a slight chance of
crossing threshold on days one, two, and three (23 Dec, 24 Dec, 25 Dec).

III. Event probabilities 23 Dec-25 Dec
Class M 60/60/60
Class X 10/10/10
Proton 10/10/10
PCAF green

IV. Penticton 10.7 cm Flux
Observed 22 Dec 138
Predicted 23 Dec-25 Dec 135/135/130
90 Day Mean 22 Dec 141

V. Geomagnetic A Indices
Observed Afr/Ap 21 Dec 004/002
Estimated Afr/Ap 22 Dec 003/003
Predicted Afr/Ap 23 Dec-25 Dec 005/005-005/005-007/010

VI. Geomagnetic Activity Probabilities 23 Dec-25 Dec
A. Middle Latitudes
Active 05/05/25
Minor Storm 01/01/10
Major-severe storm 01/01/01
B. High Latitudes
Active 15/15/15
Minor Storm 15/15/25
Major-severe storm 05/05/35