Joint USAF/NOAA Solar Geophysical Activity Report and Forecast 25 December 2013

Joint USAF/NOAA Solar Geophysical Activity Report and Forecast
SDF Number 359 Issued at 2200Z on 25 Dec 2013

IA. Analysis of Solar Active Regions and Activity from 24/2100Z to
25/2100Z: Solar activity has been at low levels for the past 24 hours.
The largest solar event of the period was a C4 event observed at
25/0639Z from old Region 1928 (S16, L=008). There are currently 5
numbered sunspot regions on the disk.

IB. Solar Activity Forecast: Solar activity is likely to be low with a
chance for M-class flares on days one, two, and three (26 Dec, 27 Dec,
28 Dec).

IIA. Geophysical Activity Summary 24/2100Z to 25/2100Z: The geomagnetic
field has been at quiet to unsettled levels for the past 24 hours. Solar
wind speed, as measured by the ACE spacecraft, reached a peak speed of
338 km/s at 25/0350Z. Total IMF reached 12 nT at 25/0524Z. The maximum
southward component of Bz reached -10 nT at 25/1121Z.

IIB. Geophysical Activity Forecast: The geomagnetic field is expected
to be at quiet to active levels on day one (26 Dec), quiet to unsettled
levels on day two (27 Dec) and quiet levels on day three (28 Dec).

III. Event probabilities 26 Dec-28 Dec
Class M 25/25/25
Class X 01/01/01
Proton 01/01/01
PCAF green

IV. Penticton 10.7 cm Flux
Observed 25 Dec 123
Predicted 26 Dec-28 Dec 125/125/125
90 Day Mean 25 Dec 142

V. Geomagnetic A Indices
Observed Afr/Ap 24 Dec 002/001
Estimated Afr/Ap 25 Dec 009/009
Predicted Afr/Ap 26 Dec-28 Dec 009/010-009/008-005/005

VI. Geomagnetic Activity Probabilities 26 Dec-28 Dec
A. Middle Latitudes
Active 25/20/10
Minor Storm 10/05/01
Major-severe storm 01/01/01
B. High Latitudes
Active 15/15/15
Minor Storm 25/25/15
Major-severe storm 35/25/10