Joint USAF/NOAA Solar Geophysical Activity Report and Forecast 17 May 2022

Joint USAF/NOAA Solar Geophysical Activity Report and Forecast
SDF Number 137 Issued at 2200Z on 17 May 2022

IA. Analysis of Solar Active Regions and Activity from 16/2100Z to 17/2100Z: Solar activity has been at low levels for the past 24 hours. The largest solar event of the period was a C9 event observed at 17/1145Z from Region 3010 (S15E10). 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 and a slight chance for an X-class flare on days one, two, and three (18 May, 19 May, 20 May).

IIA. Geophysical Activity Summary 16/2100Z to 17/2100Z: The geomagnetic field has been at quiet to unsettled levels for the past 24 hours. Solar wind speed reached a peak of 617 km/s at 17/1212Z. Total IMF reached 11 nT at 17/0636Z. The maximum southward component of Bz reached -8 nT at 17/0645Z. Electrons greater than 2 MeV at geosynchronous orbit reached a peak level of 256 pfu.

IIB. Geophysical Activity Forecast: The geomagnetic field is expected to be at quiet to unsettled levels on day one (18 May) and quiet to active levels on days two and three (19 May, 20 May).

III. Event probabilities 18 May-20 May
Class M 35/35/35
Class X 15/15/15
Proton 05/05/05
PCAF green

IV. Penticton 10.7 cm Flux
Observed 17 May 171
Predicted 18 May-20 May 170/170/170
90 Day Mean 17 May 121

V. Geomagnetic A Indices
Observed Afr/Ap 16 May 011/010
Estimated Afr/Ap 17 May 011/012
Predicted Afr/Ap 18 May-20 May 009/008-010/014-010/012

VI. Geomagnetic Activity Probabilities 18 May-20 May
A. Middle Latitudes
Active 20/30/30
Minor Storm 05/10/10
Major-severe storm 01/01/01
B. High Latitudes
Active 20/15/15
Minor Storm 30/30/30
Major-severe storm 25/40/40