Joint USAF/NOAA Solar Geophysical Activity Report and Forecast SDF Number 79 Issued at 2200Z on 20 Mar 2023

IA. Analysis of Solar Active Regions and Activity from 19/2100Z to 20/2100Z: Solar activity has been at moderate levels for the past 24 hours. The largest solar event of the period was a M1 event observed at 20/0148Z from Region 3256 (S20E39). There are currently 6 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, two, and three (21 Mar, 22 Mar, 23 Mar).

IIA. Geophysical Activity Summary 19/2100Z to 20/2100Z: The geomagnetic field has been at quiet to active levels for the past 24 hours. Solar wind speed reached a peak of 486 km/s at 20/1126Z. Total IMF reached 8 nT at 20/2034Z. The maximum southward component of Bz reached -7 nT at 20/1335Z. Electrons greater than 2 MeV at geosynchronous orbit reached a peak level of 335 pfu.

IIB. Geophysical Activity Forecast: The geomagnetic field is expected to be at quiet to active levels on day one (21 Mar) and quiet levels on days two and three (22 Mar, 23 Mar).

III. Event probabilities 21 Mar-23 Mar
Class M 25/25/25
Class X 05/05/05
Proton 01/01/01
PCAF green

IV. Penticton 10.7 cm Flux
Observed 20 Mar 156
Predicted 21 Mar-23 Mar 155/150/150
90 Day Mean 20 Mar 170

V. Geomagnetic A Indices
Observed Afr/Ap 19 Mar 008/007
Estimated Afr/Ap 20 Mar 010/012
Predicted Afr/Ap 21 Mar-23 Mar 015/018-006/005-006/005

VI. Geomagnetic Activity Probabilities 21 Mar-23 Mar
A. Middle Latitudes
Active 35/15/15
Minor Storm 15/01/01
Major-severe storm 01/01/01
B. High Latitudes
Active 15/15/15
Minor Storm 30/20/20
Major-severe storm 50/20/20

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