Joint USAF/NOAA Solar Geophysical Activity Report and Forecast SDF Number 168 Issued at 2200Z on 17 Jun 2023

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 C4 event observed at 17/1657Z from Region 3338 (N11E45). 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 (18 Jun, 19 Jun, 20 Jun).

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 690 km/s at 16/2306Z. Total IMF reached 7 nT at 16/2257Z. The maximum southward component of Bz reached -3 nT at 17/2005Z. Electrons greater than 2 MeV at geosynchronous orbit reached a peak level of 1619 pfu.

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

III. Event probabilities 18 Jun-20 Jun
Class M 30/30/30
Class X 05/05/05
Proton 01/01/01
PCAF green

IV. Penticton 10.7 cm Flux
Observed 17 Jun 158
Predicted 18 Jun-20 Jun 160/155/155
90 Day Mean 17 Jun 153

V. Geomagnetic A Indices
Observed Afr/Ap 16 Jun 024/036
Estimated Afr/Ap 17 Jun 008/008
Predicted Afr/Ap 18 Jun-20 Jun 008/008-011/012-010/012

VI. Geomagnetic Activity Probabilities 18 Jun-20 Jun
A. Middle Latitudes
Active 10/25/25
Minor Storm 01/10/10
Major-severe storm 01/05/05
B. High Latitudes
Active 15/10/10
Minor Storm 15/20/20
Major-severe storm 10/35/35

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