Joint USAF/NOAA Solar Geophysical Activity Report and Forecast 22 May 2021

Joint USAF/NOAA Solar Geophysical Activity Report and Forecast
SDF Number 142 Issued at 2200Z on 22 May 2021

IA. Analysis of Solar Active Regions and Activity from 21/2100Z to 22/2100Z: 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 22/1711Z from Region 2824 (N21E13). There are currently 1 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 (23 May, 24 May, 25 May).

IIA. Geophysical Activity Summary 21/2100Z to 22/2100Z: The geomagnetic field has been at quiet levels for the past 24 hours. Solar wind speed reached a peak of 520 km/s at 21/2308Z. Electrons greater than 2 MeV at geosynchronous orbit reached a peak level of 1035 pfu.

IIB. Geophysical Activity Forecast: The geomagnetic field is expected to be at quiet levels on days one and two (23 May, 24 May) and quiet to unsettled levels on day three (25 May).

III. Event probabilities 23 May-25 May
Class M 25/25/25
Class X 01/01/01
Proton 01/01/01
PCAF green

IV. Penticton 10.7 cm Flux
Observed 22 May 076
Predicted 23 May-25 May 076/076/076
90 Day Mean 22 May 076

V. Geomagnetic A Indices
Observed Afr/Ap 21 May 008/007
Estimated Afr/Ap 22 May 005/006
Predicted Afr/Ap 23 May-25 May 006/005-006/005-007/008

VI. Geomagnetic Activity Probabilities 23 May-25 May
A. Middle Latitudes
Active 10/10/15
Minor Storm 01/01/01
Major-severe storm 01/01/01
B. High Latitudes
Active 15/15/15
Minor Storm 20/20/25
Major-severe storm 20/20/20