Joint USAF/NOAA Solar Geophysical Activity Report and Forecast 12 April 2021

Joint USAF/NOAA Solar Geophysical Activity Report and Forecast
SDF Number 102 Issued at 2200Z on 12 Apr 2021

IA. Analysis of Solar Active Regions and Activity from 11/2100Z to 12/2100Z: Solar activity has been at very low levels for the past 24 hours. There are currently 1 numbered sunspot regions on the disk.

IB. Solar Activity Forecast: Solar activity is expected to be very low with a slight chance for a C-class flare on days one, two, and three (13 Apr, 14 Apr, 15 Apr).

IIA. Geophysical Activity Summary 11/2100Z to 12/2100Z: The geomagnetic field has been at quiet levels for the past 24 hours. Solar wind speed reached a peak of 391 km/s at 11/2234Z. Total IMF reached 6 nT at 12/0619Z. The maximum southward component of Bz reached -4 nT at 12/0545Z. Electrons greater than 2 MeV at geosynchronous orbit reached a peak level of 376 pfu.

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

III. Event probabilities 13 Apr-15 Apr
Class M 01/01/01
Class X 01/01/01
Proton 01/01/01
PCAF green

IV. Penticton 10.7 cm Flux
Observed 12 Apr 083
Predicted 13 Apr-15 Apr 078/078/078
90 Day Mean 12 Apr 076

V. Geomagnetic A Indices
Observed Afr/Ap 11 Apr 005/005
Estimated Afr/Ap 12 Apr 005/005
Predicted Afr/Ap 13 Apr-15 Apr 006/005-007/008-007/008

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