Joint USAF/NOAA Solar Geophysical Activity Report and Forecast
SDF Number 353 Issued at 2200Z on 19 Dec 2014
IA. Analysis of Solar Active Regions and Activity from 18/2100Z to 19/2100Z: Solar activity has been at high levels for the past 24 hours. The largest solar event of the period was a M6 event observed at 18/2158Z from Region 2241 (S09E04). There are currently 8 numbered sunspot regions on the disk.
IB. Solar Activity Forecast: Solar activity is expected to be moderate with a chance for X-class flares on days one, two, and three (20 Dec, 21 Dec, 22 Dec).
IIA. Geophysical Activity Summary 18/2100Z to 19/2100Z: 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 422 km/s at 19/0130Z. Total IMF reached 8 nT at 19/1224Z. The maximum southward component of Bz reached -7 nT at 19/0406Z. Electrons greater than 2 MeV at geosynchronous orbit reached a peak level of 587 pfu.
IIB. Geophysical Activity Forecast: The geomagnetic field is expected to be at quiet to minor storm levels on days one and three (20 Dec, 22 Dec) and quiet to major storm levels on day two (21 Dec). Protons have a slight chance of crossing threshold on days one, two, and three (20 Dec, 21 Dec, 22 Dec).
III. Event probabilities 20 Dec-22 Dec
Class M 75/75/75
Class X 25/25/25
IV. Penticton 10.7 cm Flux
Observed 19 Dec 216
Predicted 20 Dec-22 Dec 220/215/210
90 Day Mean 19 Dec 156
V. Geomagnetic A Indices
Observed Afr/Ap 18 Dec 005/004
Estimated Afr/Ap 19 Dec 009/010
Predicted Afr/Ap 20 Dec-22 Dec 015/018-023/035-015/018
VI. Geomagnetic Activity Probabilities 20 Dec-22 Dec