Joint USAF/NOAA Solar Geophysical Activity Report and Forecast 12 December 2015

Joint USAF/NOAA Solar Geophysical Activity Report and Forecast
SDF Number 346 Issued at 2200Z on 12 Dec 2015

IA. Analysis of Solar Active Regions and Activity from 11/2100Z to 12/2100Z: Solar activity has been at low levels for the past 24 hours. The largest solar event of the period was a C7 event observed at 12/1346Z from Region 2470 (N13E76). There are currently 7 numbered sunspot regions on the disk.

IB. Solar Activity Forecast: Solar activity is expected to be low with a chance for M-class flares on days one, two, and three (13 Dec, 14 Dec, 15 Dec).

IIA. Geophysical Activity Summary 11/2100Z to 12/2100Z: 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 720 km/s at 12/0103Z. Total IMF reached 5 nT at 11/2215Z. The maximum southward component of Bz reached -4 nT at 12/0152Z. Electrons greater than 2 MeV at geosynchronous orbit reached a peak level of 6196 pfu.

IIB. Geophysical Activity Forecast: The geomagnetic field is expected to be at quiet to unsettled levels on days one and two (13 Dec, 14 Dec) and quiet to active levels on day three (15 Dec).

III. Event probabilities 13 Dec-15 Dec
Class M 25/25/25
Class X 05/05/05
Proton 01/01/01
PCAF green

IV. Penticton 10.7 cm Flux
Observed 12 Dec 117
Predicted 13 Dec-15 Dec 120/125/125
90 Day Mean 12 Dec 108

V. Geomagnetic A Indices
Observed Afr/Ap 11 Dec 014/016
Estimated Afr/Ap 12 Dec 010/014
Predicted Afr/Ap 13 Dec-15 Dec 009/010-007/008-013/018

VI. Geomagnetic Activity Probabilities 13 Dec-15 Dec
A. Middle Latitudes
Active 15/15/35
Minor Storm 05/01/10
Major-severe storm 01/01/01
B. High Latitudes
Active 20/20/15
Minor Storm 25/30/30
Major-severe storm 20/20/45