Joint USAF/NOAA Solar Geophysical Activity Report and Forecast 28 April 2022

Joint USAF/NOAA Solar Geophysical Activity Report and Forecast
SDF Number 118 Issued at 2200Z on 28 Apr 2022

IA. Analysis of Solar Active Regions and Activity from 27/2100Z to 28/2100Z: Solar activity has been at low levels for the past 24 hours. The largest solar event of the period was a C6 event observed at 28/0306Z from Region 2996 (N25W39). There are currently 8 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 and two (29 Apr, 30 Apr) and likely to be low with a slight chance for an M-class flare on day three (01 May).

IIA. Geophysical Activity Summary 27/2100Z to 28/2100Z: The geomagnetic field has been at quiet to minor storm levels for the past 24 hours. Solar wind speed reached a peak of 551 km/s at 28/1913Z. Total IMF reached 10 nT at 28/0658Z. The maximum southward component of Bz reached -6 nT at 28/0620Z. Electrons greater than 2 MeV at geosynchronous orbit reached a peak level of 405 pfu.

IIB. Geophysical Activity Forecast: The geomagnetic field is expected to be at quiet to minor storm levels on day one (29 Apr), quiet to active levels on day two (30 Apr) and quiet to unsettled levels on day three (01 May). Protons greater than 10 Mev have a slight chance of crossing threshold on days one and two (29 Apr, 30 Apr).

III. Event probabilities 29 Apr-01 May
Class M 25/25/15
Class X 05/05/05
Proton 10/10/05
PCAF green

IV. Penticton 10.7 cm Flux
Observed 28 Apr 132
Predicted 29 Apr-01 May 125/115/110
90 Day Mean 28 Apr 119

V. Geomagnetic A Indices
Observed Afr/Ap 27 Apr 016/018
Estimated Afr/Ap 28 Apr 011/014
Predicted Afr/Ap 29 Apr-01 May 014/018-010/012-008/008

VI. Geomagnetic Activity Probabilities 29 Apr-01 May
A. Middle Latitudes
Active 40/30/20
Minor Storm 25/10/05
Major-severe storm 05/01/01
B. High Latitudes
Active 10/15/15
Minor Storm 25/25/25
Major-severe storm 60/40/25