Joint USAF/NOAA Solar Geophysical Activity Report and Forecast 26 December 2013

Joint USAF/NOAA Solar Geophysical Activity Report and Forecast
SDF Number 360 Issued at 2200Z on 26 Dec 2013

IA. Analysis of Solar Active Regions and Activity from 25/2100Z to
26/2100Z: Solar activity has been at low levels for the past 24 hours.
The largest solar event of the period was a C2 event observed at
26/0702Z from Region 1931 (S15W29). There are currently 6 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 (27 Dec, 28 Dec,
29 Dec).

IIA. Geophysical Activity Summary 25/2100Z to 26/2100Z: 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 286 km/s at
25/2220Z. Total IMF reached 6 nT at 25/2323Z. The maximum southward
component of Bz reached -5 nT at 25/2357Z.

IIB. Geophysical Activity Forecast: The geomagnetic field is expected
to be at quiet to unsettled levels on day one (27 Dec) and quiet levels
on days two and three (28 Dec, 29 Dec).

III. Event probabilities 27 Dec-29 Dec
Class M 25/25/25
Class X 01/01/01
Proton 01/01/01
PCAF green

IV. Penticton 10.7 cm Flux
Observed 26 Dec 125
Predicted 27 Dec-29 Dec 125/125/130
90 Day Mean 26 Dec 142

V. Geomagnetic A Indices
Observed Afr/Ap 25 Dec 006/007
Estimated Afr/Ap 26 Dec 004/004
Predicted Afr/Ap 27 Dec-29 Dec 008/007-005/005-006/005

VI. Geomagnetic Activity Probabilities 27 Dec-29 Dec
A. Middle Latitudes
Active 15/10/05
Minor Storm 01/01/01
Major-severe storm 01/01/01
B. High Latitudes
Active 15/15/15
Minor Storm 25/15/15
Major-severe storm 20/10/05