Joint USAF/NOAA Solar Geophysical Activity Report and Forecast 24 December 2015

Joint USAF/NOAA Solar Geophysical Activity Report and Forecast
SDF Number 358 Issued at 2200Z on 24 Dec 2015

IA. Analysis of Solar Active Regions and Activity from 23/2100Z to 24/2100Z: Solar activity has been at moderate levels for the past 24 hours. The largest solar event of the period was a M1 event observed at 24/0212Z from Region 2473 (S22E35). There are currently 3 numbered sunspot regions on the disk.

IB. Solar Activity Forecast: Solar activity is expected to be low with a chance for M-class flares and a slight chance for an X-class flare on days one and two (25 Dec, 26 Dec) and expected to be low with a chance for M-class flares on day three (27 Dec).

IIA. Geophysical Activity Summary 23/2100Z to 24/2100Z: The geomagnetic field has been at quiet to active levels for the past 24 hours. Solar wind speed, as measured by the ACE spacecraft, reached a peak speed of 573 km/s at 24/2041Z. Total IMF reached 10 nT at 24/0434Z. The maximum southward component of Bz reached -7 nT at 24/0418Z. Electrons greater than 2 MeV at geosynchronous orbit reached a peak level of 4505 pfu.

IIB. Geophysical Activity Forecast: The geomagnetic field is expected to be at quiet to active levels on day one (25 Dec) and quiet to unsettled levels on days two and three (26 Dec, 27 Dec).

III. Event probabilities 25 Dec-27 Dec
Class M 45/45/40
Class X 10/10/05
Proton 05/05/05
PCAF green

IV. Penticton 10.7 cm Flux
Observed 24 Dec 133
Predicted 25 Dec-27 Dec 135/130/125
90 Day Mean 24 Dec 110

V. Geomagnetic A Indices
Observed Afr/Ap 23 Dec 007/007
Estimated Afr/Ap 24 Dec 010/013
Predicted Afr/Ap 25 Dec-27 Dec 011/012-010/010-008/008

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