Joint USAF/NOAA Solar Geophysical Activity Report and Forecast 10 April 2021

Joint USAF/NOAA Solar Geophysical Activity Report and Forecast
SDF Number 100 Issued at 2200Z on 10 Apr 2021

IA. Analysis of Solar Active Regions and Activity from 09/2100Z to 10/2100Z: Solar activity has been at very low levels for the past 24 hours. There are currently 0 numbered sunspot regions on the disk.

IB. Solar Activity Forecast: Solar activity is expected to be very low on days one, two, and three (11 Apr, 12 Apr, 13 Apr).

IIA. Geophysical Activity Summary 09/2100Z to 10/2100Z: The geomagnetic field has been at quiet levels for the past 24 hours. Solar wind speed reached a peak of 404 km/s at 09/2205Z. Total IMF reached 5 nT at 10/1848Z. The maximum southward component of Bz reached -4 nT at 10/1451Z. Electrons greater than 2 MeV at geosynchronous orbit reached a peak level of 141 pfu.

IIB. Geophysical Activity Forecast: The geomagnetic field is expected to be at quiet to unsettled levels on day one (11 Apr) and quiet levels on days two and three (12 Apr, 13 Apr).

III. Event probabilities 11 Apr-13 Apr
Class M 01/01/01
Class X 01/01/01
Proton 01/01/01
PCAF green

IV. Penticton 10.7 cm Flux
Observed 10 Apr 070
Predicted 11 Apr-13 Apr 071/071/071
90 Day Mean 10 Apr 076

V. Geomagnetic A Indices
Observed Afr/Ap 09 Apr 002/002
Estimated Afr/Ap 10 Apr 005/005
Predicted Afr/Ap 11 Apr-13 Apr 008/008-006/005-006/005

VI. Geomagnetic Activity Probabilities 11 Apr-13 Apr
A. Middle Latitudes
Active 25/10/10
Minor Storm 05/01/05
Major-severe storm 01/01/01
B. High Latitudes
Active 20/15/15
Minor Storm 30/20/20
Major-severe storm 25/20/15