Joint USAF/NOAA Solar Geophysical Activity Report and Forecast 21 April 2022

Joint USAF/NOAA Solar Geophysical Activity Report and Forecast
SDF Number 111 Issued at 2200Z on 21 Apr 2022

IA. Analysis of Solar Active Regions and Activity from 20/2100Z to 21/2100Z: Solar activity has been at high levels for the past 24 hours. The largest solar event of the period was a M9 event observed at 21/0159Z from Region 2993 (N22E08). There are currently 5 numbered sunspot regions on the disk.

IB. Solar Activity Forecast: Solar activity is expected to be moderate with a chance for X-class flares on days one, two, and three (22 Apr, 23 Apr, 24 Apr).

IIA. Geophysical Activity Summary 20/2100Z to 21/2100Z: The geomagnetic at 21/1859Z. Total IMF reached 11 nT at 21/1130Z. The maximum southward component of Bz reached -8 nT at 21/1139Z. Electrons greater than 2 MeV at geosynchronous orbit reached a peak level of 1365 pfu.

IIB. Geophysical Activity Forecast: The geomagnetic field is expected to be at quiet levels on day one (22 Apr), quiet to active levels on day two (23 Apr) and quiet to unsettled levels on day three (24 Apr).

III. Event probabilities 22 Apr-24 Apr
Class M 75/75/75
Class X 25/25/25
Proton 05/05/05
PCAF green

IV. Penticton 10.7 cm Flux
Observed 21 Apr 164
Predicted 22 Apr-24 Apr 160/160/160
90 Day Mean 21 Apr 116

V. Geomagnetic A Indices
Observed Afr/Ap 20 Apr 009/007
Estimated Afr/Ap 21 Apr 010/009
Predicted Afr/Ap 22 Apr-24 Apr 006/005-010/012-009/008

VI. Geomagnetic Activity Probabilities 22 Apr-24 Apr
A. Middle Latitudes
Active 15/30/20
Minor Storm 01/10/05
Major-severe storm 01/01/01
B. High Latitudes
Active 15/15/15
Minor Storm 20/25/25
Major-severe storm 20/40/30