Joint USAF/NOAA Solar Geophysical Activity Report and Forecast 25 December 2012

Joint USAF/NOAA Solar Geophysical Activity Report and Forecast
SDF Number 360 Issued at 2200Z on 25 Dec 2012

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
25/1304Z from Region 1635 (N11W17). There are currently 3 numbered
sunspot regions on the disk.
IB. Solar Activity Forecast: Solar activity is expected to be at low
levels 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 levels for the past 24 hours. Solar wind speed,
as measured by the ACE spacecraft, reached a peak speed of 344 km/s at
25/0252Z. Total IMF reached 5.3 nT at 25/0334Z. The maximum southward
component of Bz reached -3.9 nT at 25/1629Z.
IIB. Geophysical Activity Forecast: The geomagnetic field is expected
to be at quiet levels for the next two days (26 – 27 December). By day
three (28 December), activity is expected to increase to quiet to
unsettled levels.
III. Event probabilities 26 Dec-28 Dec
Class M 05/05/05
Class X 01/01/01
Proton 01/01/01
PCAF green

IV. Penticton 10.7 cm Flux
Observed 25 Dec 113
Predicted 26 Dec-28 Dec 115/115/120
90 Day Mean 25 Dec 119

V. Geomagnetic A Indices
Observed Afr/Ap 24 Dec 002/002
Estimated Afr/Ap 25 Dec 002/003
Predicted Afr/Ap 26 Dec-28 Dec 005/005-005/005-007/008

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