Joint USAF/NOAA Solar Geophysical Activity Report and Forecast 13 April 2021

Joint USAF/NOAA Solar Geophysical Activity Report and Forecast
SDF Number 103 Issued at 2200Z on 13 Apr 2021

IA. Analysis of Solar Active Regions and Activity from 12/2100Z to 13/2100Z: 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 (14 Apr, 15 Apr, 16 Apr).

IIA. Geophysical Activity Summary 12/2100Z to 13/2100Z: The geomagnetic field has been at quiet levels for the past 24 hours. Solar wind speed reached a peak of 383 km/s at 12/2137Z. Total IMF reached 7 nT at 13/1932Z. The maximum southward component of Bz reached -3 nT at 13/0854Z. Electrons greater than 2 MeV at geosynchronous orbit reached a peak level of 126 pfu.

IIB. Geophysical Activity Forecast: The geomagnetic field is expected to be at quiet levels on day one (14 Apr), quiet to unsettled levels on day two (15 Apr) and quiet to active levels on day three (16 Apr).

III. Event probabilities 14 Apr-16 Apr
Class M 01/01/01
Class X 01/01/01
Proton 01/01/01
PCAF green

IV. Penticton 10.7 cm Flux
Observed 13 Apr 073
Predicted 14 Apr-16 Apr 074/074/072
90 Day Mean 13 Apr 076

V. Geomagnetic A Indices
Observed Afr/Ap 12 Apr 004/004
Estimated Afr/Ap 13 Apr 005/005
Predicted Afr/Ap 14 Apr-16 Apr 006/005-007/008-014/018

VI. Geomagnetic Activity Probabilities 14 Apr-16 Apr
A. Middle Latitudes
Active 10/20/40
Minor Storm 01/05/15
Major-severe storm 01/01/01
B. High Latitudes
Active 15/15/10
Minor Storm 20/25/25
Major-severe storm 15/25/50